Hukkelhoven, C.W.P.M.

Validity of self-reported data on pregnancies for childhood cancer survivors: A comparison with data from a nationwide population-based registry (Article)

2013-03-01T00:00:00Z

Study Question: To what degree do records registered in the Netherlands Perinatal Registry (PRN) agree with self-report in a Study Question: naire on pregnancy outcomes in childhood cancer survivors (CCSs)? Summary Answer: This study suggests that self-reported pregnancy outcomes of CCSs agree well with registry data and that outcomes reported by CCSs agree better with registry data than do those of controls. What is Known Already: Many studies have shown that childhood cancer treatment may affect fertility outcomes in female CCSs; however, these conclusions were often based on questionnaire data, and it remains unclear whether self-report agrees well with more objective sources of information. Study Design , Size, Duration In an nationwide cohort study on fertility (inclusion period January 2008 and April 2011, trial number: NTR2922), 1420 CCSs and 354 sibling controls were invited to complete a questionnaire regarding socio-demographic characteristics and reproductive history. In total, 879 CCSs (62%) and 287 controls (81%) returned the questionnaire. Participants/Materials, Setting, Methods The current validation study compared the agreement between pregnancy outcomes as registered in the PRN and self-reported outcomes in the Study Question: naire. A total of 589 pregnancies were reported in CCSs, and 300 pregnancies in sibling controls, of which 524 could be linked to the PRN. Main Results and the Role of Chancea high intra-class correlation coefficient (ICC) was found for birthweight (BW) (0.94 and 0.87 for CCSs and controls, respectively). The self-reported BWs tended to be higher than reported in the PRN. For gestational age (GA), the ICC was high for CCSs (0.88), but moderate for controls (0.49). CCSs overestimated GA more often than controls. The Kappa values for method of conception and for method of delivery were moderate to good. Multilevel analyses on the mean difference with regard to BW and GA showed no differences associated with time since pregnancy or educational level. Limitations, Reasons For Caution Not all pregnancies reported could be linked to the registry data. In addition, the completeness of the PRN could not be assessed precisely, because there is no information on the number of missing records. Finally, for some outcomes there were high proportions of missing values in the PRN registry. Wider Implications of the Findings: Our study suggests that questionnaires are a reliable method of data collection, and that for most variables, self-report agrees well with registry data. Study Funding/Competing Interes: TThis work was supported by the Dutch Cancer Society (grant no. VU 2006-3622) and by Foundation Children Cancer Free. None of the authors report a conflict of interest. Study Funding/Competing Interes: 2922 http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2922. © 2013 The Author.

Advanced maternal age, short interpregnancy interval, and perinatal outcome (Article)

2011-05-01T00:00:00Z

Objective: The purpose of this study was to evaluate whether the association between short interpregnancy intervals and perinatal outcome varies with maternal age. Study Design: We performed a retrospective cohort study among 263,142 Dutch women with second deliveries that occurred between 2000 and 2007. Outcome variables were preterm delivery (<37 weeks of gestation), low birthweight in term deliveries (<2500 g) and small-for-gestational age (<10th percentile for gestational age on the basis of sex- and parity-specific Dutch standards). Results: Short interpregnancy intervals (<6 months) was associated positively with preterm delivery and low birthweight, but not with being small for gestational age. The association of short interpregnancy interval with the risk of preterm delivery was weaker among older than younger women. There was no clear interaction between short interpregnancy interval and maternal age in relation to low birthweight or small for gestational age. Conclusion: The results of this study indicate that the association of short interpregnancy interval with preterm delivery attenuates with increasing maternal age.

Increased adverse perinatal outcome of hospital delivery at night (Article)

2010-08-01T00:00:00Z

Objective To determine whether delivery in the evening or at night and some organisational features of maternity units are related to perinatal adverse outcome. Design A 7-year national registry-based cohort study. Setting All 99 Dutch hospitals. Population From nontertiary hospitals (n = 88), 655 961 singleton deliveries from 32 gestational weeks onwards, and, from tertiary centres (n = 10), 108 445 singleton deliveries from 22 gestational weeks onwards. Methods Multiple logistic regression analysis of national perinatal registration data over the period 2000-2006. In addition, multilevel analysis was applied to investigate whether the effects of time of delivery and other variables systematically vary across different hospitals. Main outcome measures Delivery-related perinatal mortality (intrapartum or early neonatal mortality) and combined delivery-related perinatal adverse outcome (any of the following: intrapartum or early neonatal mortality, 5-minute Apgar score below 7, or admission to neonatal intensive care). Results After case mix adjustment, relative to daytime, increased perinatal mortality was found in nontertiary hospitals during the evening (OR, 1.32; 95% CI, 1.15-1.52) and at night (OR, 1.47; 95% CI, 1.28-1.69) and, in tertiary centres, at night only (OR, 1.20; 95% CI, 1.06-1.37). Similar significant effects were observed using the combined perinatal adverse outcome measure. Multilevel analysis was unsuccessful; extending the initial analysis with nominal hospital effects and hospital-delivery time interaction effects confirmed the significant effect of night in nontertiary hospitals, whereas other organisational effects (nontertiary, tertiary) were taken up by the hospital terms. Conclusion Hospital deliveries at night are associated with increased perinatal mortality and adverse perinatal outcome. The time of delivery and other organisational features representing experience (seniority of staff, volume) explain hospital-to-hospital variation.

Pregnancy outcome in female childhood cancer survivors (Article)

2010-05-01T00:00:00Z

BACKGROUND: The number of childhood cancer survivors has dramatically increased and consequently, an increasing number of survivors may now wish to conceive. Recently, several studies have described that previous treatment with abdominal radiotherapy may increase the risk of adverse pregnancy outcome.METHODSWe conducted a retrospective single centre cohort study of childhood cancer survivors with a singleton live birth between January 2000 and December 2005. Pregnancy outcome was compared with data from the Netherlands Perinatal Registry, a nationwide database of pregnancy outcome parameters of all births in the Netherlands registered by midwives, obstetricians and paediatricians.RESULTSData were available on 40 survivors and 9031 controls. Median age at diagnosis was 6.9 years (range 0.1-16.8 years). The median interval between diagnosis and date of delivery was 21.6 years (range 7.4-36.1 years). In the whole cohort, pregnancy outcome was not different between survivors and controls. However, survivors treated with abdominal radiotherapy delivered preterm and had post-partum haemorrhage (mean gestational age in survivors = 34.9 versus 39.2 weeks in controls, P = 0.001; 33 in survivors versus 5 in controls, P = 0.007, respectively). The offspring of survivors had normal birthweight after adjustment for gestational age (mean birthweight in offspring of survivors 2503 versus 1985 g; P = 0.22).CONCLUSIONChildhood cancer survivors irradiated to the abdomen have an earlier delivery and higher incidence of post-partum haemorrhage. This stresses the need for close monitoring of the delivery, including inpatient perinatal care, in this group of childhood cancer survivors.

Neonatal outcome following elective cesarean section beyond 37 weeks of gestation: a 7-year retrospective analysis of a national registry (Article)

2010-03-01T00:00:00Z

Objective: We sought to evaluate number and timing of elective cesarean sections at term and to assess perinatal outcome associated with this timing. Study Design: We conducted a recent retrospective cohort study including all elective cesarean sections of singleton pregnancies at term (n = 20,973) with neonatal follow-up. Primary outcome was defined as a composite of neonatal mortality and morbidity. Results: More than half of the neonates were born at <39 weeks of gestation, and they were at significantly higher risk for the composite primary outcome than neonates born thereafter. The absolute risks were 20.6% and 12.5% for birth at <38 and 39 weeks, respectively, as compared to 9.5% for neonates born ≥39 weeks. The corresponding adjusted odds ratios (95% confidence interval) were 2.4 (2.1-2.8) and 1.4 (1.2-1.5), respectively. Conclusion: More than 50% of the elective cesarean sections are applied at <39 weeks, thus jeopardizing neonatal outcome.

A systematic review finds methodological improvements necessary for prognostic models in determining traumatic brain injury outcomes (Article)

2008-04-01T00:00:00Z

Objectives: To describe the modeling techniques used for early prediction of outcome in traumatic brain injury (TBI) and to identify aspects for potential improvements. Study Design and Setting: We reviewed key methodological aspects of studies published between 1970 and 2005 that proposed a prognostic model for the Glasgow Outcome Scale of TBI based on admission data. Results: We included 31 papers. Twenty-four were single-center studies, and 22 reported on fewer than 500 patients. The median of the number of initially considered predictors was eight, and on average five of these were selected for the prognostic model, generally including age, Glasgow Coma Score (or only motor score), and pupillary reactivity. The most common statistical technique was logistic regression with stepwise selection of predictors. Model performance was often quantified by accuracy rate rather than by more appropriate measures such as the area under the receiver-operating characteristic curve. Model validity was addressed in 15 studies, but mostly used a simple split-sample approach, and external validation was performed in only four studies. Conclusion: Although most models agree on the three most important predictors, many were developed on small sample sizes within single centers and hence lack generalizability. Modeling strategies have to be improved, and include external validation.

Prognosis after traumatic brain injury (Doctoral Thesis)

2005-12-22T00:00:00Z

This thesis describes studies on prognosis after severe or moderate traumatic brain injury (TBI). In Chapter 1, the clinical problem of TBI is discussed. TBI is generally defined as an injury to the brain caused by an external physical force, such as a traffic accident, a fall or a gunshot. TBI is an important public health care problem in the western world. It is one of the most common causes of death in young adults and it can affect people’s lives enormously. The focus of this thesis is on developing and validating prognostic models: statistical models that combine individual patient characteristics to predict the probability of a particular outcome or disease state. The objectives of this thesis were: (1) to study methodological developments in prognostic modeling in TBI; (2) to develop and validate prognostic models that predict long- term outcome for patients with severe or moderate TBI an (3) to predict the need of specialized intensive care to aid a more efficient triage of patients.