Dieleman, J.P.

The risk of new onset heart failure associated with dopamine agonist use in Parkinson's disease (Article)

2012-03-01T00:00:00Z

The aim of present study was to investigate the risk of heart failure associated with dopamine agonist use in patients with Parkinson's disease. The data sources of this study were four different population-based, healthcare databases in United Kingdom, Italy and Netherlands. A case control study nested within a cohort of Parkinson's disease patients who were new users of either dopamine agonist or levodopa was conducted. Incident cases of heart failure were identified and validated, using Framingham criteria. Controls were matched to cases on age, gender and database. To estimate the risk of newly diagnosed heart failure with ergot and non-ergot derived dopamine agonists, as compared to levodopa, odds ratios and 95% confidence intervals were calculated through conditional logistic regression. In the cohort of 25,459 Parkinson's disease patients (11,151 new users of dopamine agonists, 14,308 new users of levodopa), 518 incident heart failure cases were identified during follow-up. Compared to levodopa, no increased risk of heart failure was found for ergot dopamine agonists (odds ratio: 1.03; 95% confidence interval: 0.69-1.55). Among non-ergot dopamine agonists, only pramipexole was associated with an increased risk of heart failure (odds ratio: 1.61; 95%confidence interval: 1.09-2.38), especially in the first three months of therapy (odds ratio: 3.06; 95% confidence interval: 1.74-5.39) and in patients aged 80 years and older (odds ratio: 3.30; 95% confidence interval: 1.62-7.13). The results of this study indicate that ergot dopamine agonist use in Parkinson's disease patients was not associated with an increased risk of newly diagnosed heart failure. Among non-ergot dopamine agonists, we observed a statistically significant association between pramipexole use and heart failure, especially during the first months of therapy and in very old patients.

Safety of pandemic H1N1 vaccines in children and adolescents (Article)

2011-10-06T00:00:00Z

During the 2009 influenza A (H1N1) pandemic several pandemic H1N1 vaccines were licensed using fast track procedures, with relatively limited data on the safety in children and adolescents. Different extensive safety monitoring efforts were put in place to ensure timely detection of adverse events following immunization. These combined efforts have generated large amounts of data on the safety of the different pandemic H1N1 vaccines, also in children and adolescents. In this overview we shortly summarize the safety experience with seasonal influenza vaccines as a background and focus on the clinical and post marketing safety data of the pandemic H1N1 vaccines in children. We identified 25 different clinical studies including 10,505 children and adolescents, both healthy and with underlying medical conditions, between the ages of 6 months and 23 years. In addition, large monitoring efforts have resulted in large amounts of data, with almost 13,000 individual case reports in children and adolescents to the WHO. However, the diversity in methods and data presentation in clinical study publications and publications of spontaneous reports hampered the analysis of safety of the different vaccines. As a result, relatively little has been learned on the comparative safety of these pandemic H1N1 vaccines - particularly in children. It should be a collective effort to give added value to the enormous work going into the individual studies by adhering to available guidelines for the collection, analysis, and presentation of vaccine safety data in clinical studies and to guidance for the clinical investigation of medicinal products in the pediatric population. Importantly the pandemic has brought us the beginning of an infrastructure for collaborative vaccine safety studies in the EU, USA and globally.

Guillain-Barré syndrome: Background incidence rates in the Netherlands (Article)

2011-09-01T00:00:00Z

Guillain-Barré syndrome (GBS) is a (sub)acute polyradiculoneuropathy, which may occur following immunization. To interpret the occurrence of GBS after introduction of large-scale immunization programmes, it is important to define recent background incidence rates (IRs) of GBS. We used a general practitioner electronic medical record database to assess age-specific GBS IRs between 1996 and 2008 in The Netherlands. All possible GBS cases were manually reviewed. Validated incident cases were reviewed by a neurologist (B. J.) for diagnostic certainty using the GBS case definition of the Brighton Collaboration (BC). In a population of 638,891 persons, we identified 23 validated incident GBS cases (mean age 46 years). IR was 1.14 per 100,000 person years (95% confidence interval [CI] 0.67-1.61) and was lower for people under 50 years (0.76; 95%CI 0.41-1.32) compared with elderly of 50 years or older (1.80; 95%CI 0.98-3.05). Only six cases fulfilled level 1 or 2 of diagnostic certainty of the BC case definition. IR of GBS increases with age. As vaccinations are often targeted at specific age groups, age-specific rates should be used to monitor GBS observed versus expected rates after introduction of large-scale vaccination programmes.

Effectiveness of a MF-59™-adjuvanted pandemic influenza vaccine to prevent 2009 A/H1N1 influenza-related hospitalisation; a matched case-control study (Article)

2011-07-18T00:00:00Z

Background: During the 2009 influenza A/H1N1 pandemic, adjuvanted influenza vaccines were used for the first time on a large scale. Results on the effectiveness of the vaccines in preventing 2009 influenza A/H1N1-related hospitalisation are scanty and varying.Methods: We conducted a matched case-control study in individuals with an indication for vaccination due to underlying medical conditions and/or age ≥ 60 years in the Netherlands. Cases were patients hospitalised with laboratory-confirmed 2009 A/H1N1 influenza infection between November 16, 2009 and January 15, 2010. Controls were matched to cases on age, sex and type of underlying medical condition(s) and drawn from an extensive general practitioner network. Conditional logistic regression was used to estimate the vaccine effectiveness (VE = 1 - OR). Different sensitivity analyses were used to assess confounding by severity of underlying medical condition(s) and the effect of different assumptions for missing dates of vaccination.Results: 149 cases and 28,238 matched controls were included. It was estimated that 22% of the cases and 28% of the controls received vaccination more than 7 days before the date of onset of symptoms in cases. A significant number of breakthrough infections were observed. The VE was estimated at 19% (95%CI -28-49). After restricting the analysis to cases with controls suffering from severe underlying medical conditions, the VE was 49% (95%CI 16-69).Conclusions: The number of breakthrough infections, resulting in modest VE estimates, suggests that the MF-59™ adjuvanted vaccine may have had only a limited impact on preventing 2009 influenza A/H1N1-related hospitalisation in this setting. As the main aim of influenza vaccination programmes is to reduce severe influenza-related morbidity and mortality from influenza in persons at high risk of complications, a more effective vaccine, or additional preventive measures, are needed.

Guillain-Barré syndrome and adjuvanted pandemic influenza A (H1N1) 2009 vaccine: Multinational case-control study in Europe (Article)

2011-07-16T00:00:00Z

Objective: To assess the association between pandemic influenza A (H1N1) 2009 vaccine and Guillain-Barré syndrome. Design: Case-control study. Setting: Five European countries. Participants: 104 patients with Guillain-Barré syndrome and its variant Miller-Fisher syndrome matched to one or more controls. Case status was classified according to the Brighton Collaboration definition. Controls were matched to cases on age, sex, index date, and country. Main outcome measures: Relative risk estimate for Guillain-Barré syndrome after pandemic influenza vaccine. Results: Case recruitment and vaccine coverage varied considerably between countries; the most common vaccines used were adjuvanted (Pandemrix and Focetria). The unadjusted pooled risk estimate for all countries was 2.8 (95% confidence interval 1.3 to 6.0). After adjustment for influenza-like illness/upper respiratory tract infection and seasonal influenza vaccination, receipt of pandemic influenza vaccine was not associated with an increased risk of Guillain-Barré syndrome (adjusted odds ratio 1.0, 0.3 to 2.7). The 95% confidence interval shows that the absolute effect of vaccination could range from one avoided case of Guillain-Barré syndrome up to three excess cases within six weeks after vaccination in one million people. Conclusions: The risk of occurrence of Guillain-Barré syndrome is not increased after pandemic influenza vaccine, although the upper limit does not exclude a potential increase in risk up to 2.7-fold or three excess cases per one million vaccinated people. When assessing the association between pandemic influenza vaccines and Guillain-Barré syndrome it is important to account for the effects of influenza-like illness/upper respiratory tract infection, seasonal influenza vaccination, and calendar time.

Suboptimal gastroprotective coverage of NSAID use and the risk of upper gastrointestinal bleeding and ulcers: An observational study using three European databases (Article)

2011-06-02T00:00:00Z

Background: Gastro-protective agents (GPA) are co-prescribed with non-steroidal anti-inflammatory drugs (NSAID) to lower the risk of upper gastrointestinal (UGI) events. It is unknown to what extent the protective effect is influenced by therapy adherence. Aim: To study the association between GPA adherence and UGI events among non-selective (ns) NSAID users. Methods: The General Practice Research Database (UK 1998e2008), the Integrated Primary Care Information database (the Netherlands 1996-2007) and the Health Search/CSD Longitudinal Patient Database (Italy 2000-2007) were used. A nested case-control design was employed within a cohort of nsNSAID users aged ≥50 years, who also used a GPA. UGI event cases (UGI bleeding and/or symptomatic ulcer with/without obstruction/perforation) were matched to event-free members of the cohort for age, sex, database and calendar time. Adherence to GPA was calculated as the proportion of nsNSAID treatment days covered by a GPA prescription. Adjusted OR with 95% CI were calculated. Results: The cohort consisted of 618 684 NSAID users, generating 1 107 266 nsNSAID episodes. Of these, 117 307 (10.6%) were (partly) covered by GPA, 4.9% of which with a GPA coverage <20% (non-adherence), and 68.1% with a GPA coverage >80% (full adherence). 339 patients experienced an event. Among non-adherers, the OR was 2.39 (95% CI 1.66 to 3.44) for all UGI events and 1.89 (95% CI 1.09 to 3.28) for UGI bleeding alone, compared to full adherers. Conclusions: The risk of UGI events was significantly higher in nsNSAID users with GPA non-adherence. This underlines the importance of strategies to improve GPA adherence. Copyright Article author (or their employer) 2011.

A nationwide study of three invasive treatments for trigeminal neuralgia (Article)

2011-03-01T00:00:00Z

Invasive procedures for treatment of trigeminal neuralgia (TGN) include percutaneous radiofrequency thermocoagulation (PRT), partial sensory rhizotomy (PSR), and microvascular decompression (MVD). Using a nationwide discharge registry from The Netherlands, we assessed the frequency of use and patient characteristics, and evaluated treatment failure for each patient undergoing PRT, PSR, or MVD from January 2002 through December 2004. Only patients without a procedure in the year prior were included. Primary outcome was readmission for repeat procedures for TGN or known complications within 1 year. Comparability of patient populations was assessed through propensity scores based on hospital, age, sex, and comorbidity. Conditional logistic regression matched on propensity score was used to calculate relative risks (RR) with 95% confidence intervals (CIs) for repeat procedures or complications. During the study period, 672 patients with TGN underwent PRT, 39 underwent PSR, and 87 underwent MVD. Hospital type was the predominant determinant of procedure type; age, sex, and comorbidity were weak predictors. The RR for repeat procedures for PSR was 0.21 (95% CI: 0.07 to 0.65) and for MVD was 0.13 (95% CI: 0.05 to 0.35) compared with PRT (RR 1). For complications, the RR of PSR was 5.36 (95% CI: 1.46 to 19.64) and of MVD was 4.40 (95% CI: 1.44 to 13.42). Sex, urbanization, and comorbidity did not influence prognosis, but hospital and surgical volume did. In conclusion, although PSR and MVD are associated with a lower risk of repeat procedure than PRT, they seem to be more prone to complications requiring hospital readmission. Microvascular decompression and partial sensory rhizotomy are associated with a lower risk of undergoing a repeat procedure compared with percutaneous radiofrequency thermocoagulation but are more prone to complications requiring readmission to hospital.

A nationwide study of three invasive treatments for trigeminal neuralgia (Article)

2011-01-01T00:00:00Z

Association between calcium channel blockers and gingival hyperplasia (Article)

2010-07-01T00:00:00Z

Aim: To study the effect of the dose and type of calcium channel blockers (CCBs) on the risk of gingival hyperplasia and to quantify this association. Methods: The study was conducted within the Integrated Primary Care Information Project in The Netherlands. A nested case-control study was designed within a cohort of all patients who were new users of either CCBs or drugs interacting with the renin-angiotensin system (RAS). Cases were all individuals with a validated diagnosis of gingival hyperplasia. Controls were matched on age, gender and index date. Results: Within the study population, 103 cases of gingival hyperplasia were identified and matched to 7677 controls. The risk of gingival hyperplasia was higher in current users of CCBs [adjusted odds ratio (ORadj) 2.2, 95% confidence intervals (95% CI): 1.4-3.4], especially in dihydropyridines (ORadj2.1, 95% CI: 1.3-3.5) and benzothiazepine derivatives (ORadj2.9, 95% CI: 1.3-6.5) than in RAS drug users. The risk increased in patients using more than the recommended daily dose (ORadj3.0, 95% CI: 1.6-5.5) and when the duration of current use was <1 month (ORadj5.2, 95% CI: 2.1-12.6). Conclusion: This study shows that the risk of gingival hyperplasia is twofold higher in current users of CCBs than in users of RAS drugs. The association was dose dependent and the highest for dihydropyridines or benzothiazepine derivates.

Risk of Ischemic Stroke Associated with Antidepressant Drug Use in Elderly Persons (Article)

2010-06-01T00:00:00Z

Competing hypotheses have been formulated about a possible association between selective serotonin reuptake inhibitors (SSRIs) and ischemic stroke. However, the relationship between antidepressant drug use and ischemic stroke is still unclear. The aim of the study was to assess the association between the use of different types of antidepressants and the risk of ischemic stroke in elderly outpatients.A population-based, nested, case-control study was conducted in persons 65 years and older in the Integrated Primary Care Information database (1996-2005). Cases were all patients with a validated first ischemic stroke. Controls were matched on year of birth, sex, and index date. Exposure to antidepressants was divided in current, past, and nonuse and further categorized by type (SSRI, tricyclic, and other antidepressants), dose, and duration. Conditional logistic regression was used to compare the risk of ischemic stroke between users of antidepressants and nonusers.Overall, 996 incident ischemic strokes were identified. Current use of SSRIs was associated with a significantly increased risk as compared with nonuse (odds ratio, 1.55; 95% confidence interval, 1.07-2.25) in elderly patients, particularly when used for less than six months. No associations were observed for current use of tricyclic and other antidepressant drugs.To summarize, compared with nonuse, only SSRI use seems to be associated with an increased risk of ischemic stroke in elderly patients, particularly as a short-term effect.

Exposure to colorectal examinations before a colorectal cancer diagnosis: A case-control study (Article)

2010-04-01T00:00:00Z

Objectives: To assess the prior exposure to colorectal examinations between colorectal cancer (CRC) patients and matched control participants to estimate the effect of these examinations on the development of CRC and to obtain insight into the background incidence of colorectal examinations. Methods: A population-based case-control study was conducted within the Dutch Integrated Primary Care Information database over the period 1996-2005. All incident CRC cases were matched with up to 18 controls (n=7790) for age, sex, index date (date of CRC diagnosis) and follow-up before diagnosis. All colorectal examinations performed in symptomatic participants in the period 0.5-5 years before index date were considered in the analyses. Results: Within the source population of 457024 persons, we identified 594 incident cases of CRC. In the period 0.5-5 years before index date 2.9% (17 of 594) of the CRC cases had undergone colorectal examinations, compared with 4.4% (346 of 7790) in the control population [odds ratio (ORadj): 0.56, 95% confidence interval (CI): 0.33-0.94]. For left-sided CRC, significantly more controls than cases had undergone a colorectal examination (4.7 vs. 2.0%, respectively, ORadj: 0.36, 95% CI: 0.17-0.76), which was not seen for right-sided CRCs (3.3 vs. 3.9%, respectively, ORadj: 0.98, 95% CI: 0.42-2.25). Conclusion: Patients diagnosed with CRC were less likely than controls to have had a colorectal examination in previous years, being more pronounced in patients diagnosed with left-sided CRCs. If diagnostic examinations have a similar protective effect as screening examinations, this finding supports the concept that colorectal examination can have a major impact on the reduction of CRC risk.

Pharmacological Treatment of Neuropathic Facial Pain in the Dutch General Population (Article)

2010-03-01T00:00:00Z

Few drugs are registered for treatment of neuropathic facial pain (NFP), and not much is known about treatment choices for NFP in daily practice. Patients with NFP were identified in the IPCI-database with longitudinal electronic general practitioner (GP) records. We described prescription patterns of pain medication following first symptoms. Off-label, off-guideline use, failure and reasons for failure were assessed. Failure was defined as treatment switch, exacerbation, adverse event, or invasive treatment for NFP. Of 203 NFP cases, 160 (79%) received pharmacological pain treatment. Most patients (90%) were initially treated by a GP with anti-epileptic drugs (55%) or NSAIDs (16%) as monotherapy. The median treatment delay was 0 days (range 0 to 2,478 days). Adverse events were experienced by 16 (10%) of patients. Sixty-two percent of first prescriptions were in adherence to guidelines and 59% were considered on-label while 34% of prescriptions were both off-label and off-guideline. Of the first therapy, 38% failed within 3 months. The median duration until failure was 251 days. General practitioners usually are the first to treat NFP. They usually prescribe drugs licensed for NFP and according to guidelines, but the extent of off-label use is substantial. Initial treatment often failed within a short period after starting therapy. Perspective: This drug-utilization study describes the pharmacological treatment of different forms of neuropathic facial pain in daily practice. Although treatment is mostly initiated rapidly by general practitioners in a correct way, it often contains off-label or off-guideline medication. Failure of the initial treatment is common and occurs rapidly as well.

Incidence of facial pain in the general population (Article)

2009-12-15T00:00:00Z

Facial pain has a considerable impact on quality of life. Accurate incidence estimates in the general population are scant. The aim was therefore to estimate the incidence rate (IR) of trigeminal neuralgia (TGN), postherpetic neuralgia (PHN), cluster headache (CH), occipital neuralgia (ON), local neuralgia (LoN), atypical facial pain (AFP), glossopharyngeal neuralgia (GPN) and paroxysmal hemicrania (PH) in the Netherlands. In the population-based Integrated Primary Care Information (IPCI) medical record database potential facial pain cases were identified from codes and narratives. Two medical doctors reviewed medical records, questionnaires from general practitioners and specialist letters using criteria of the International Association for the Study of Pain. A pain specialist arbitrated if necessary and a random sample of all cases was evaluated by a neurologist. The date of onset was defined as date of first specific symptoms. The IR was calculated per 100,000 PY. Three hundred and sixty-two incident cases were ascertained. The overall IR [95% confidence interval] was 38.7 [34.9-42.9]. It was more common among women compared to men. Trigeminal neuralgia and cluster headache were the most common forms among the studied diseases. Paroxysmal hemicrania and glossopharyngeal neuralgia were among the rarer syndromes. The IR increased with age for all diseases except CH and ON, peaking in the 4th and 7th decade, respectively. Postherpetic neuralgia, CH and LoN were more common in men than women. From this we can conclude that facial pain is relatively rare, although more common than estimated previously based on hospital data.

Outcome of the complex regional pain syndrome (Article)

2009-09-01T00:00:00Z

Objectives: The outcome of complex regional pain syndrome (CRPS) is relatively unknown. High disease resolution rates have been reported, but also long-lasting impairments in many patients. This study aims to assess CRPS outcome in a population-based cohort of CRPS patients. Methods: CRPS patients were retrospectively identified (1996 to 2005) in a Dutch general practitioners database, the integrated primary care information project, and included if at onset (ie, in the past) they had complied with the International Association for the Study of Pain (IASP) diagnostic criteria. The disease status at minimum of 2 years since onset was assessed during visits using questionnaires, interviews, and physical examination. Symptoms and signs were compared with reference patients with an identical past injury but without CRPS. Actual fulfillment of the IASP criteria, treatment status, self-reported recovery, and working status were recorded. Moreover, to identify the potential prognostic factors, baseline patient characteristics were compared across subgroups according to the CRPS outcome. These subgroups were derived by cluster analysis on actual symptoms and signs. Results: One hundred and two CRPS patients were assessed at on average 5.8 years (range: 2.1 to 10.8) since onset. CRPS patients displayed higher symptom and sign prevalences in all categories (sensory, vasomotor, sudomotor, and motor/trophic) than controls. Sixteen percent (95% CI: 9-22) reported the CRPS as still progressive, whereas 31% (95% CI: 19-43) were incapable of working. Patients in the poorest outcome cluster more often had their upper extremity affected, event other than a fracture, and cold CRPS. Discussion: Severe CRPS outcome is rare, but a majority of patients has persistent impairments at 2 or more years since onset.

Referral and treatment patterns for complex regional pain syndrome in the Netherlands (Article)

2009-07-01T00:00:00Z

Background: Patients with complex regional pain syndrome (CRPS) are seen and treated by a variety of physicians. The present study aims to describe referral and treatment patterns for CRPS patients in the Netherlands. Methods: Patients, who were selected (1996-2005) from an electronic general practice (GP) database (Integrated Primary Care Information Project), were invited for study participation, involving diagnosis verification (International Association for the Study of Pain criteria) and assessment of referrals and treatment through information retrieved from GP journals, patients' questionnaires, pharmacy dispensing lists and specialist letters if available. Results: One hundred and two patients were included. Sixty-one percent had presented first at the GP, while 80% subsequently consulted one or more medical specialists, most frequently an anesthetist (55% of the cases) or a specialist in rehabilitation medicine (41%). Over 90% of the patients received oral or topical pharmacotherapy, 45% received intravenous therapy, 89% received non-invasive therapy (i.e. physiotherapy) and 18% received nerve blocks. Analgesics and free radical scavengers were administered early during CRPS, while vasodilating drugs and drugs against neuropathic pain (antidepressants and anti-epileptics) were administered later on. Pharmacotherapy was usually initiated by a medical specialist. Conclusion: The Dutch treatment guidelines, issued in 2006, recommend free radical scavenger prescription (plus physiotherapy) as the initial treatment step for CRPS. Until 2005 only half of the patients received a scavenger within 3 months after disease onset, and the majority presents first at the GP, in particular GPs may be encouraged to initiate treatment with scavengers, while waiting for the results of further specialist consultation.

The association between ACE inhibitors and the complex regional pain syndrome: Suggestions for a neuro-inflammatory pathogenesis of CRPS (Article)

2009-04-01T00:00:00Z

Antihypertensive drugs interact with mediators that are also involved in complex regional pain syndrome (CRPS), such a neuropeptides, adrenergic receptors, and vascular tone modulators. Therefore, we aimed to study the association between the use of antihypertensive drugs and CRPS onset. We conducted a population-based case-control study in the Integrated Primary Care Information (IPCI) database in the Netherlands. Cases were identified from electronic records (1996-2005) and included if they were confirmed during an expert visit (using IASP criteria), or if they had been diagnosed by a medical specialist. Up to four controls per cases were selected, matched on gender, age, calendar time, and injury. Exposure to angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor antagonists, β-blockers, calcium channel blockers, and diuretics was assessed from the automated prescription records. Data were analyzed using multivariate conditional logistic regression. A total of 186 cases were matched to 697 controls (102 confirmed during an expert visit plus 84 with a specialist diagnosis). Current use of ACE inhibitors was associated with an increased risk of CRPS (ORadjusted: 2.7, 95% CI: 1.1-6.8). The association was stronger if ACE inhibitors were used for a longer time period (ORadjusted: 3.0, 95% CI: 1.1-8.1) and in higher dosages (ORadjusted: 4.3, 95% CI: 1.4-13.7). None of the other antihypertensive drug classes was significantly associated with CRPS. We conclude that ACE inhibitor use is associated with CRPS onset and hypothesize that ACE inhibitors influence the neuro-inflammatory mechanisms that underlie CRPS by their interaction with the catabolism of substance P and bradykinin.

Estrogens and the risk of complex regional pain syndrome (CRPS) (Article)

2009-03-09T00:00:00Z

Objective: Since complex regional pain syndrome (CRPS) shows a clear female predominance, we investigated the association between the cumulative as well as current exposure to estrogens, and CRPS. Methods: A population-based case-control study was conducted in the Integrated Primary Care Information (IPCI) project in the Netherlands. Cases were identified from electronic records (1996-2005) and included if they were confirmed during a visit (using International Association for the Study of Pain Criteria), or had been diagnosed by a specialist. Controls were matched to cases on gender, age, calendar time, and injury. Measures of cumulative endogenous estrogen exposure were obtained by questionnaire and included age of menarche and menopause, menstrual life, and cumulative months of pregnancy and breast-feeding. Current estrogen exposure at CRPS onset was retrieved from the electronic medical records and determined by current pregnancy or by the use of oral contraceptive (OC) drugs or hormonal replacement therapy (HRT). Results: Hundred and forty-three female cases (1493 controls) were included in analyses on drug use and pregnancies, while cumulative endogenous estrogen exposure was studied in 53 cases (58 controls) for whom questionnaire data were available. There was no association between CRPS and either cumulative endogenous estrogen exposure, OC, or HRT use. CRPS onset was increased during the first 6 months after pregnancy (OR: 5.6, 95%CI: 1.0-32.4), although based on small numbers. Discussion: We did not find an association between CRPS onset and cumulative endogenous estrogen exposure or current OC or HRT use, but more powered studies are needed to exclude potential minor associations. Copyright

No modification of the beneficial effect of NSAIDs on colorectal cancer by CYP2C9 genotype (Article)

2009-01-01T00:00:00Z

Background: CYP2C9 enzymes are involved in non-steroidal anti-inflammatory drug (NSAID) metabolism. Therefore, we investigated whether CYP2C9*2 and *3 variant alleles, encoding for enzymes with lower activity, increased the protective effect of NSAIDs on colorectal cancer. Methods: Individual and combined associations of NSAIDs and CYP2C9*2 and 3 variant alleles with colorectal cancer were studied in 7757 Caucasian individuals of The Rotterdam Study, a population-based prospective cohort since 1990. Additive and multiplicative effect modification models were used to examine drug-gene interactions. Results: There were 212 incident cases of colorectal cancer during follow-up. A reduced risk of colorectal cancer was observed in individuals who used NSAIDs for more than a year (HR 0.45; 95% CI 0.28 to 0.71), and in carriers of an CYP2C9 variant allele associated with lower enzymatic activity (HR 0.67; 95% CI 0.47 to 0.96). The combination of both determinants was associated with a further risk reduction but without synergy. Conclusion: Both NSAID use and CYP2C9*2 and/or *3 carriage are associated with a reduced risk of colorectal cancer. However, no interaction between the determinants was found, which might indicate independent pathophysiological mechanisms.

Medical history and the onset of complex regional pain syndrome (CRPS) (Article)

2008-10-15T00:00:00Z

Knowledge concerning the medical history prior to the onset of complex regional pain syndrome (CRPS) might provide insight into its risk factors and potential underlying disease mechanisms. To evaluate prior to CRPS medical conditions, a case-control study was conducted in the Integrated Primary Care Information (IPCI) project, a general practice (GP) database in the Netherlands. CRPS patients were identified from the records and validated through examination by the investigator (IASP criteria) or through specialist confirmation. Cases were matched to controls on age, gender and injury type. All diagnoses prior to the index date were assessed by manual review of the medical records. Some pre-specified medical conditions were studied for their association with CRPS, whereas all other diagnoses, grouped by pathogenesis, were tested in a hypothesis-generating approach. Of the identified 259 CRPS patients, 186 cases (697 controls) were included, based on validation by the investigator during a visit (102 of 134 visited patients) or on specialist confirmation (84 of 125 unvisited patients). A medical history of migraine (OR: 2.43, 95% CI: 1.18-5.02) and osteoporosis (OR: 2.44, 95% CI: 1.17-5.14) was associated with CRPS. In a recent history (1-year before CRPS), cases had more menstrual cycle-related problems (OR: 2.60, 95% CI: 1.16-5.83) and neuropathies (OR: 5.7; 95% CI: 1.8-18.7). In a sensitivity analysis, including only visited cases, asthma (OR: 3.0; 95% CI: 1.3-6.9) and CRPS were related. Psychological factors were not associated with CRPS onset. Because of the hypothesis-generating character of this study, the findings should be confirmed by other studies.

Prevalence and treatment of hypertensive patients with multiple concomitant cardiovascular risk factors in The Netherlands and Italy (Article)

2008-08-01T00:00:00Z

The Anglo-Scandinavian Cardiac Outcomes Trial-Lipid-Lowering Arm (ASCOT-LLA) trial demonstrated the benefits of combined antihypertensive/ lipid-lowering treatment over antihypertensive treatment alone in hypertensive patients with ≥3 additional cardiovascular (CV) risk factors. We assessed the prevalence and treatment of patients with hypertension and ≥3 additional CV risk factors in The Netherlands and Italy in a retrospective cohort study using the Integrated Primary Care Information (IPCI) database in The Netherlands and the Health Search/ Thales Database (HSD) in Italy. Patients aged ≥16 years, with 1 year of valid database history, diagnosed and/or treated for hypertension (>140/90 mmHg) during 2000-2002 were included in the study. The IPCI and HSD populations consisted of ∼175 000 and ∼325 000 patients, respectively. The prevalence of hypertension increased from 20.3 to 22.3% in the IPCI, and from 19.0 to 21.8% in the HSD during 2000-2002. The prevalence of ≥3 concomitant risk factors among hypertensive patients increased from 31.2 and 31.1% in 2000 to 34.2 and 39.3% in 2002 in the IPCI and HSD, respectively. From 2000 to 2002, among hypertensive patients with ≥3 CV risk factors and no prior symptomatic CV disease (CVD) approximately 54-57% in the IPCI and 80-83% in the HSD received antihypertensive treatment. In these patients, the use of combined antihypertensive and lipid-lowering treatment increased from 14.2 to 17.6% in the IPCI and from 15.5 to 17.4% in the HSD from 2000 to 2002. This study shows that primary prevention of CVD in hypertensive patients in The Netherlands and Italy could be improved.

Selective serotonin reuptake inhibiting antidepressants are associated with an increased risk of nonvertebral fractures (Article)

2008-08-01T00:00:00Z

BACKGROUND:: Fractures related to osteoporosis and falling constitute a major health problem in the elderly population. Exposure to antidepressants is associated with an increased risk of falls and fractures, but most previous studies incriminate tricyclic antidepressants (TCAs) rather than selective serotonin reuptake inhibitors (SSRIs). OBJECTIVE:: To examine the association between antidepressants, including TCAs, SSRIs, and other antidepressants and the risk of nonvertebral fractures in elderly. DESIGN:: Prospective population-based cohort study. SETTING:: The Rotterdam Study, consisting of 7983 individuals aged 55 years and older. PARTICIPANTS:: All persons from the Rotterdam Study. RESULTS:: One thousand two hundred nineteen persons experienced a nonvertebral fracture, 25 during TCA use and 18 during SSRI use. After adjustment for age, sex, lower-limb disability, and depression, the risk of nonvertebral fracture was 2.35 (95% confidence interval, 1.32-4.18) for current users of SSRIs compared with nonusers of antidepressants. Multiple adjusting for many possible risk factors did not affect the association. To deal with potential confounding by indication, we subsequently restricted the analysis to antidepressant users (n = 1217). Compared with past users of TCAs or SSRIs, current users of SSRIs had a 2.07-fold (95% confidence interval, 1.23-3.50) increased risk of fracture, which further increased with prolonged use. In this analysis, depressive state at baseline and during follow-up did not play a role, suggesting absence of confounding by indication. The use of TCAs was associated with an increased fracture risk that decreased with prolonged use. CONCLUSIONS:: Not only users of TCAs but also of SSRIs have a significantly increased risk of nonvertebral fractures, in SSRI users especially after prolonged use. Despite fewer early adverse effects of SSRIs, physicians treating elderly depressive patients should be aware of the unfavorable long-term consequence of SSRIs on fracture risk.

Mortality benefits of influenza vaccination in elderly people (Article)

2008-08-01T00:00:00Z

Incidence rates and treatment of neuropathic pain conditions in the general population (Article)

2008-07-31T00:00:00Z

Incidence rate estimates of neuropathic pain are scanty and mostly address single types whereas the scope of the disease is wide. We aimed to calculate the incidence rates of neuropathic pain conditions in the Dutch general population and to assess treatment strategies in primary care. The study population included persons registered for at least one year in the Integrated Primary Care Information (IPCI) database between 1996 and 2003. Neuropathic pain was ascertained and classified by systematic review of computerized longitudinal medical records. Incidence rates (IR) were calculated, and the treatment for pain was compared to age and gender matched controls. Among 362,693 persons contributing 1,116,215 person years (PY), we identified 9135 new cases of neuropathic pain (IR: 8.2/1000 PY, 95%CI: 8.0-8.4). Mononeuropathy and carpal tunnel syndrome were the most frequent types with 4.3 and 2.3 cases/1000 PY followed by diabetic peripheral neuropathy and post-herpetic neuralgia at 0.72 and 0.42/1000 PY. Neuropathic pain was 63% more common in women than in men and peaked between the ages 70 and 79. More than 50% of cases received pain medication within 6 months after diagnosis, mostly consisting of NSAIDs or aspirin. Anticonvulsants and tricyclic antidepressants were only used by 4.8 and 4.7% of cases. Neuropathic pain is a rather frequent condition with an annual incidence of almost 1% of the general population and affecting women and middle-aged persons more often. The treatment mostly consisted of regular analgesics suggesting that pharmacological treatment of neuropathic pain is suboptimal.

Gastro-oesophageal reflux, medical resource utilization and upper gastrointestinal endoscopy in patients at risk of oesophageal adenocarcinoma (Article)

2008-07-01T00:00:00Z

Background: Early identification of patients at risk of oesophageal adenocarcinoma (OAC) might improve survival. Aim: To assess the medical resource utilization in the 3 years before OAC diagnosis as potential markers for early identification and intervention. Methods: We identified 65 incident OAC within the Integrated Primary Care Information database. For comparison, we randomly selected 260 age- and gender-matched population controls. We abstracted the use of gastric acid inhibitors, general practitioner (GP) and specialist care, and gastroscopies in the 3 years before the detection of OAC. Results: Approximately 20% of the cases used gastric acid inhibitors in the third and second year before OAC, which increased to almost 50% in the last year, compared to approximately 10% among controls. Only in the 6 months before OAC, the proportion of patients visiting a GP (97%) or specialist (41%) increased compared to controls. Of 13 gastroscopies performed in the 3 years, six (46%) were not suspect for a malignancy. Conclusions: Only a minority of all OAC patients used acid inhibitors before diagnosis. The use of medical care between cases and controls differed only in the final year before OAC diagnosis. Detection of early neoplastic changes proves to be difficult.

Adverse drug reaction-related hospitalisations: A population-based cohort study (Article)

2008-04-01T00:00:00Z

Purpose: To evaluate the extent, charscteristics and determinants of adverse drug reaction (ADR)-related hospitalisations on a population-based level in 2003. Methods: We performed a cohort study in the Integrated Primary Care Information (IPCI) database, a general practitioners (GPs) research database with longitudinal data from electronic patient records of a group of 150 GP throughout the Netherlands. Hospital discharge letters and patient records were reviewed to evaluate ADR-related hospitalisations applying WHO causality criteria. The prevalence of ADR-related hospitalisations per total admissions and the incidence per drug group were calculated. Avoidability and seriousness of the ADRs causing admission were assessed applying the algorithm from Hallas. Results: We identified 3515 hospital admissions, 1277 elective and 2238 acute. Of the acute admissions, 115 were caused by an ADR giving a prevalence of 5.1% (95% confidence intervals (Cl): 4.3-6.1%). The prevalence of ADR-related acute admissions increased with age up to 9.8% (95%CI: 7.5-12.7) for persons >75 years. The ADRs that most frequently caused hospitalisations were gastro-intestinal bleeding with anti-thrombotics, bradycardia/hypotension with cardiovascular drugs and neutropenic fever with cytostatics. The incidence rate of ADR-related hospitalisations per drug group was highest for anti-thrombotics and anti-infectives and was relatively low for cardiovascular drugs. Fatality as a direct consequence of the ADR-related admission was 0.31 %. In elderly patients 40% of the ADRs causing hospitallisation werejudged to be avoidable. Conclusions: The extent and potential avoidability of ADR-related hospitalisations is still substantial, especially in elderly patients. Measures need to be put into place to reduce the burden of ADRs. Copyright

Common ATP-binding cassette B1 variants are associated with increased digoxin serum concentration (Article)

2008-04-01T00:00:00Z

BACKGROUND AND OBJECTIVE: Digoxin is a known substrate of ATP-binding cassette B1 (ABCB1/MDR1). The results of studies on the association between ABCB1 polymorphisms and digoxin kinetics, however, remain contradictory. Almost all studies were small and involved only single dose kinetics. The goal of this study was to establish ABCB1 genotype effect on digoxin blood concentrations in a large cohort of chronic digoxin users in a general Dutch European population. METHODS: Digoxin users were identified in the Rotterdam Study, a prospective population-based cohort study of individuals aged 55 years and above. Digoxin blood levels were gathered from regional hospitals and laboratories. ABCB1 single nucleotide polymorphisms (SNPs) 1236C→T, 2677G→T/A, and 3435C→T were assessed on peripheral blood DNA using Taqman assays. We studied the association between the ABCB1 genotypes and haplotypes, and digoxin blood levels using linear regression models adjusting for potential confounders. RESULTS: Digoxin serum levels and DNA were available for 195 participants (56.4% women, mean age 79.4 years). All three ABCB1 variants were significantly associated with serum digoxin concentration (0.18-0.21 μg/l per additional T allele). The association was even stronger for the 1236-2677-3435 TTT haplotype allele [0.26 μg/l (95% CI 0.14-0.38)], but absent for other haplotypes (CGC allele considered referent), suggesting an interaction of SNPs in a causal haplotype instead of individual SNP effects. CONCLUSION: We found that the common ABCB1 1236C→T, 2677G→T, and 3435C→T variants and the associated TTT haplotype were associated with higher digoxin serum concentrations in a cohort of elderly European digoxin users in the general population.

The effect of anticholinergic agents on gastro-oesophageal reflux and related disorders (Article)

2008-03-01T00:00:00Z

The most important risk factor of oesophageal adenocarcinoma is gastro-oesophageal reflux disease. Gastro-oesophageal reflux disease is in itself a common disorder, giving bothersome symptoms. In daily clinical practice, anticholinergic drugs are believed to increase the risk of gastro-oesophageal reflux through effects on the lower oesophageal sphincter. In this review we discuss the available literature on the potential association between the use of drugs with anticholinergic properties and the risk of gastro-oesophageal reflux-related disorders.

Tricyclic antidepressants and the risk of reflux esophagitis (Article)

2007-09-01T00:00:00Z

OBJECTIVE: Incompetence of the lower esophageal sphincter (LES) is a key factor in the pathogenesis of gastroesophageal reflux disease (GERD). Drugs with anticholinergic properties, such as tricyclic antidepressants (TCAs), may facilitate GERD by a relaxing effect on the LES. AIM: To investigate whether the use of TCAs is associated with an increased risk of reflux esophagitis (RE). METHOD: A population-based case-control study was conducted within a large Dutch primary care database over the period 1996-2005. Cases with endoscopy-confirmed RE were identified and matched with up to 10 controls on gender, age, GP practice, and calendar time. Exposure to TCAs was assessed in the year prior to diagnosis and categorized as current (last prescription covered or ended within one month prior to the index date), past, and no use. The relative risk of RE was estimated by odds ratios (OR) with 95% confidence intervals (95% CI) using multivariate conditional logistic regression analysis. RESULTS: During the study period, 1,462 cases with endoscopy-confirmed RE were identified. The risk of RE was increased in current TCA users (ORadj1.61, 95% CI 1.04-2.50). Drug-specific analyses revealed that only clomipramine was associated with an increased risk of RE (ORadj4.6, 95% CI 2.0-10.6) in a duration- and dose-dependent manner (ORadj7.1, 95% CI 2.7-19.2 for use >180 days and ORadj9.2, 95% CI 1.6-51.5 for >1 DDD equivalent/day). CONCLUSION: No association was observed between the risk of RE and the use of TCAs other than clomipramine. The association between RE and clomipramine might be drug-related or a result of the underlying indication.

Adherence to gastroprotection and the risk of NSAID-related upper gastrointestinal ulcers and haemorrhage (Article)

2007-07-01T00:00:00Z

Background: Upper gastrointestinal (UGI) complications are a well-recognized risk of NSAID treatment, requiring preventive measures in high-risk patients. Adherence to gastroprotective agents (GPAs) in NSAID users has been suggested to be suboptimal. Aim: To investigate the association between adherence to GPAs (proton pump inhibitors or H2-receptor antagonists) and the risk of NSAID-related UGI ulcers or haemorrhage in high-risk patients. Methods: A population-based nested case-control study was conducted within a cohort of new NSAID users with at least one risk factor for a NSAID-related UGI complication, identified in the Dutch IPCI database during 1996-2005. Adherence to GPAs was calculated as the proportion of NSAID treatment days covered (PDC) by a GPA prescription. Multivariate conditional logistic regression analysis was used to calculate odds ratios with 95% confidence intervals (95% CI). Results: Fifteen percent of the non-selective NSAID users received GPAs. The risk of a NSAID-related UGI complication among NSAID users increased 16% for every 10% decrease in adherence. Compared to patients with a PDC of >80%, patients with PDCs of 20-80% and <20% had a 2.5-fold (95% CI: 1.0-6.7) respectively 4.0-fold (95% CI: 1.2-13.0) increased risk. Conclusion: There is a strong inverse relationship between adherence to GPAs and the risk of UGI complications in high-risk NSAID users.

The incidence of complex regional pain syndrome: A population-based study (Article)

2007-05-01T00:00:00Z

The complex regional pain syndrome (CRPS) is a painful disorder that can occur in an extremity after any type of injury, or even spontaneously. Data on the incidence of CRPS are scarce and mostly hospital based. Therefore the size of the problem and its burden on health care and society are unknown. The objective of the present study was to estimate the incidence of CRPS in the general population. A retrospective cohort study was conducted during 1996-2005 in the Integrated Primary Care Information (IPCI) project, a general practice research database with electronic patient record data from 600,000 patients throughout the Netherlands. Potential CRPS cases were identified by a sensitive search algorithm including synonyms and abbreviations for CRPS. Subsequently, cases were validated by electronic record review, supplemented with original specialist letters and information from an enquiry of general practitioners. The estimated overall incidence rate of CRPS was 26.2 per 100,000 person years (95% CI: 23.0-29.7). Females were affected at least three times more often than males (ratio: 3.4). The highest incidence occurred in females in the age category of 61-70 years. The upper extremity was affected more frequently than the lower extremity and a fracture was the most common precipitating event (44%). The observed incidence rate of CRPS is more as four times higher than the incidence rate observed in the only other population-based study, performed in Olmsted County, USA. Postmenopausal woman appeared to be at the highest risk for the development of CRPS.

Spironolactone and risk of upper gastrointestinal events: population based case-control study (Article)

2006-01-01T00:00:00Z

OBJECTIVE: To confirm and quantify any association between spironolactone and upper gastrointestinal bleeding and ulcers. DESIGN: Population based case-control study. SETTING: A primary care information database in the Netherlands. PARTICIPANTS: All people on the database who were aged 18 or more between 1 January 1996 and 30 September 2003. Patients with a history of alcoholism or gastrointestinal cancer were excluded. Ten controls were matched to each case of gastroduodenal ulcer or upper gastrointestinal bleeding by age (year of birth), sex, and index date. MAIN OUTCOME MEASURES: The occurrence of an upper gastrointestinal event (bleeding or ulcers), adjusted for potential confounders with conditional logistic regression analysis. RESULTS: Within the source population of 306 645 patients, 523 cases of gastric or duodenal ulcer or upper gastrointestinal bleeding were identified and matched to 5230 controls. Current use of spironolactone was associated with a 2.7-fold (95% confidence interval 1.2 to 6.0) increased risk of a gastrointestinal event. CONCLUSION: The risk of gastroduodenal ulcers or upper gastrointestinal bleeding is significantly increased in patients using spironolactone.

Non-cardiac QTc-prolonging drugs and the risk of sudden cardiac death. (Article)

2005-10-01T00:00:00Z

AIMS: To assess the association between the use of non-cardiac QTc-prolonging drugs and the risk of sudden cardiac death. METHODS AND RESULTS: A population-based case-control study was performed in the Integrated Primary Care Information (IPCI) project, a longitudinal observational database with complete medical records from more than 500,000 persons. All deaths between 1 January 1995 and 1 September 2003 were reviewed. Sudden cardiac death was classified based on the time between onset of cardiovascular symptoms and death. For each case, up to 10 random controls were matched for age, gender, date of sudden death, and general practice. The exposure of interest was the use of non-cardiac QTc-prolonging drugs. Exposure at the index date was categorized into three mutually exclusive groups of current use, past use, and non-use. The study population comprised 775 cases of sudden cardiac death and 6297 matched controls. Current use of any non-cardiac QTc-prolonging drug was associated with a significantly increased risk of sudden cardiac death (adjusted OR: 2.7; 95% CI: 1.6-4.7). The risk of death was highest in women and in recent starters. CONCLUSION: The use of non-cardiac QTc-prolonging drugs in a general population is associated with an increased risk of sudden cardiac death.

Increasing incidence of Barrett's oesophagus in the general population (Article)

2005-01-01T00:00:00Z

BACKGROUND: Barrett's oesophagus (BO) predisposes to oesophageal adenocarcinoma. Epidemiological data suggest that the incidence of BO is rising but it is unclear whether this reflects a true rise in incidence of BO or an increase in detection secondary to more upper gastrointestinal endoscopies performed. This study aimed to examine the changes in BO incidence relative to the number of upper gastrointestinal endoscopies performed in the general population. METHODS: We conducted a cohort study using the Integrated Primary Care Information database. This general practice research database contains the complete and longitudinal electronic medical records of more than 500,000 persons. RESULTS: In total, 260 incident cases of BO were identified during the study period. The incidence of BO increased from 14.3/100,000 person years in 1997 (95% confidence interval (CI) 8.6-22.4) to 23.1/100,000 person years (95% CI 17.2-30.6) in 2002 (r2 = 0.87). The number of upper gastrointestinal endoscopies decreased from 7.2/1000 person years (95% CI 6.7-7.7) to 5.7/1000 person years (95% CI 5.4-6.1) over the same time period. This resulted in an overall increase in detected BO per 1000 endoscopies from 19.8 (95% CI 12.0-31.0) in 1997 to 40.5 (95% CI 30.0-53.5) in 2002 (r2 = 0.93). The incidence of adenocarcinoma increased from 1.7/100,000 person years (95% CI 0.3-5.4) in 1997 to 6.0/100,000 person years (95% CI 3.3-10.2) in 2002 (r2 = 0.87). CONCLUSION: The incidence of diagnosed BO is increasing, independent of the number of upper gastrointestinal endoscopies that are being performed. This increase in BO incidence will likely result in a further increase in the incidence of oesophageal adenocarcinomas in the near future.

Annual revaccination against influenza and mortality risk in community-dwelling elderly persons. (Article)

2004-11-03T00:00:00Z

CONTEXT: Although large-scale observational studies have demonstrated the effectiveness of influenza vaccination, no large studies have systematically addressed the clinical benefit of annual revaccinations. OBJECTIVE: To investigate the effect of annual influenza revaccination on mortality in community-dwelling elderly persons. DESIGN, SETTING, AND PARTICIPANTS: A population-based cohort study using the computerized Integrated Primary Care Information (IPCI) database in the Netherlands including community-dwelling individuals aged 65 years or older from 1996 through 2002. For each year, we computed the individual cumulative exposure to influenza vaccination since study start. MAIN OUTCOME MEASURE: Association between the number of consecutive influenza vaccinations and all-cause mortality vs no vaccination after adjusting for age, sex, chronic respiratory and cardiovascular disease, hypertension, diabetes mellitus, renal failure, and cancer. RESULTS: The study population included 26,071 individuals, of whom 3485 died during follow-up. Overall, a first vaccination was associated with a nonsignificant annual reduction of mortality risk of 10% (hazard ratio [HR], 0.90; 95% confidence interval [CI], 0.78-1.03) while revaccination was associated with a reduced mortality risk of 24% (HR, 0.76; 95% CI, 0.70-0.83). Compared with a first vaccination, revaccination was associated with a reduced annual mortality risk of 15% (HR, 0.85; 95% CI, 0.75-0.96). During the epidemic periods this reduction was 28% (HR, 0.72; 95% CI, 0.53-0.96). Similar estimates were obtained for persons with and without chronic comorbidity and those aged 70 years or older at baseline. Overall, influenza vaccination is estimated to prevent 1 death for every 302 vaccinees at a vaccination coverage that varied between 64% and 74%. CONCLUSION: Annual influenza vaccination is associated with a reduction in all-cause mortality risk in a population of community-dwelling elderly persons, particularly in older individuals.

Underutilization of preventive strategies in patients receiving NSAIDs. (Article)

2003-01-01T00:00:00Z

BACKGROUND: Multiple treatment guidelines for non-steroidal anti-inflammatory drugs (NSAIDs) suggest that patients with one or more risk factors for NSAID-associated upper gastrointestinal (UGI) ulcer complications should be prescribed preventive strategies such as acid-suppressive drugs, misoprostol or cyclooxygenase (COX)-2-specific inhibitors to reduce their risk of serious ulcer complications. The purpose of the present study was to evaluate the extent to which new NSAID users receive recommended preventive strategies and to assess the association between risk factors and a prescription of acid suppressive drugs or misoprostol. METHOD: A retrospective observational cohort study was conducted using the Integrated Primary Care Information (IPCI) database, a longitudinal database of electronic general practitioner patient records in The Netherlands. The study population comprised all new NSAID users, defined as users of non-specific NSAIDs, COX-2-preferential NSAIDs and COX-2-specific inhibitors, during the period from January 1996 to April 2002. Subjects were excluded if they had an H2-receptor antagonist (H2RA), proton pump inhibitor (PPI) or misoprostol prescription in the 3 months prior to the first NSAID prescription. Preventive use of acid-suppressive drugs or misoprostol was identified by the coprescription for these drugs on the same day (+/-2 days) as the NSAID prescription. The drug use for each patient was validated as having a preventive indication by reviewing the physician-recorded symptoms and diagnoses. Risk factors for UGI ulcer events were defined as age >65 yr, UGI history (gastroduodenal ulcer, UGI bleeding, dyspepsia) and concomitant medications (anticoagulants, aspirin, oral corticosteroids). The study population comprised 69 648 new NSAID users. RESULTS: Overall, 7.9% of NSAID users received a preventive strategy (6.6% received a gastroprotective agent and an additional 1.3% received COX-2-specific inhibitors). Patients using preventive drugs had higher odds of having one or more UGI risk factors than patients without preventive drugs [adjusted odds ratio (OR) 1.78, 95% confidence interval 1.66-1.92]. Despite the greater rate of preventive drug prescriptions in patients who may have been at higher risk, 86.6% of patients with one risk factor and 81.2% with two or more risk factors received no preventive strategies. In contrast to non-specific NSAIDs, patients who received a prescription for a COX-2-specific inhibitor had significantly lower adjusted odds (OR = 0.22) of having H2RA/PPI or misoprostol coprescribed. CONCLUSIONS: Although patients who are treated with preventive strategies have higher odds of having gastrointestinal risk factors than those not prescribed preventive therapies, the majority (>80%) of patients with one or more gastrointestinal risk factors do not receive the recommended NSAID treatment regimen of a COX-2-specific inhibitor or NSAID + H2RA/PPI or misoprostol and are therefore undertreated.

Safety aspects of HIV-protease inhibitors (Doctoral Thesis)

2002-06-12T00:00:00Z

The objectives of this thesis were to provide more insight into the risk and risk factors of adverse drug reactions associated with HIV-protease inhibitor treatment under non-experimental everyday circumstances. By recognition of risk factors, patients at risk can be identified beforehand and risk management can be targeted more efficiently, hence ultimately improving the safety of HIV-protease inhibitor treatment. In the studies presented in this thesis we applied multiple research strategies. tn which the nationwide ATHENA cohort played a central role.

Persistent sterile leukocyturia is associated with impaired renal function in human immunodeficiency virus type 1-infected children treated with indinavir (Article)

2002-01-01T00:00:00Z

BACKGROUND: Prolonged administration of indinavir is associated with the occurrence of a variety of renal complications in adults. These well-documented side effects have restricted the use of this potent protease inhibitor in children. DESIGN: A prospective study to monitor indinavir-related nephrotoxicity in a cohort of 30 human immunodeficiency virus type 1-infected children treated with indinavir. METHODS: Urinary pH, albumin, creatinine, the presence of erythrocytes, leukocytes, bacteria and crystals, and culture were analyzed every 3 months for 96 weeks. Serum creatinine levels were routinely determined at the same time points. Steady-state pharmacokinetics of indinavir were done at week 4 after the initiation of indinavir. RESULTS: The cumulative incidence of persistent sterile leukocyturia (> or =75 cells/ micro L in at least 2 consecutive visits) after 96 weeks was 53%. Persistent sterile leukocyturia was frequently associated with a mild increase in the urine albumin/creatinine ratio and by microscopic hematuria. The cumulative incidence of serum creatinine levels >50% above normal was 33% after 96 weeks. Children with persistent sterile leukocyturia more frequently had serum creatinine levels of 50% above normal than those children without persistent sterile leukocyturia. In children younger than 5.6 years, persistent sterile leukocyturia was significantly more frequent than in older children. A higher cumulative incidence of persistent leukocyturia was found in children with an area under the curve >19 mg/L x h or a peak serum level of indinavir >12 mg/L. In 4 children, indinavir was discontinued because of nephrotoxicity. Subsequently, the serum creatinine levels decreased, the urine albumin/creatinine ratios returned to zero, and the leukocyturia disappeared within 3 months. CONCLUSIONS: Children treated with indinavir have a high cumulative incidence of persistent sterile leukocyturia. Children with persistent sterile leukocyturia more frequently had an increase in serum creatinine levels of >50% above normal. Younger children have an additional risk for renal complications. The impairment of the renal function in these children occurred in the absence of clinical symptoms of nephrolithiasis. Indinavir-associated nephrotoxicity must be monitored closely, especially in children with risk factors such as persistent sterile leukocyturia, age <5.6 years, an area under the curve of indinavir >19 mg/L x h, and a C(max) >12 mg/L.