http://repub.eur.nl/res/aut/29803/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/34782/ 2012-01-01T00:00:00Z BACKGROUND: In the literature there is a range from 1% to 20% of duplication (up to 20%) of the great saphenous vein (GSV) reported, because there is a lack of an accurate definition of the GSV and objective parameters for an anatomical identification. OBJECTIVE: To investigate the frequency of true duplications of the GSV. MATERIALS AND METHODS: A systematic review of the literature, a retrospective analysis of duplex examinations, and a prospective study of duplex examinations to investigate the frequency of true duplications of the GSV. RESULTS: In the literature review, a great variety of definitions is used for duplication of the GSV. Before the consensus of the Union International de Phlébologie (UIP) in 2006, Only in a small number of studies, the definition of the GSV in the saphenous compartment between the fascial blades is mentioned. CONCLUSION: Phlebographic studies have been the criterion standard for the identification of venous anatomy. Now, duplex is regarded as the criterion standard for accurate detection of the veins. True duplication of the GSV is less common than the previous literature has suggested, namely 1.6% to 2%. It is recommended that the duplicated GSV should be treated to avoid an important risk of recurrence of venous insufficiency. http://repub.eur.nl/res/pub/24115/ 2009-03-09T00:00:00Z Purpose: Antidepressants are used for many indications besides depression. This makes investigating depression treatment outcomes in prescription databases problematic when the indication is unknown. The aim of our study is to develop an algorithm to identify antidepressant drug users from prescription data that suffer from depression. Methods: Data for deriving the algorithm were obtained from the Second Dutch National Survey of General Practice, carried out in 2001 by The Netherlands Institute for Health Services Research (NIVEL), and for validation the Integrated Primary Care Information (IPCI) database was used. Both sets included adults receiving their first antidepressant drug in 2001 (n = 1855 and 3321, respectively). The outcome was a registered diagnosis of depression. Covariates investigated for developing the algorithm were patient and prescribing characteristics, and co-medication. Results: The predictive algorithm included age, SSRI prescribed on the index date, prescribed dose, general practitioner as prescriber and the number of antidepressant prescriptions prescribed plus medication for treating acid related disorders, laxatives, cardiac therapy or hypnotics/ sedatives prescribed in the 6 months prior to index date. The probability that the algorithm correctly identified an antidepressant drug user as having a depression diagnosis was 79% with a sensitivity of 79.6% and a specificity of 66.9%. Conclusion: In conclusion, we developed and validated an algorithm that can be used to compose cohorts of patients treated with antidepressants for depression from prescription databases. Copyright http://repub.eur.nl/res/pub/30376/ 2008-02-26T00:00:00Z Background. In pre-school children a diagnosis of asthma is not easily made and only a minority of wheezing children will develop persistent atopic asthma. According to the general consensus a diagnosis of asthma becomes more certain with increasing age. Therefore the congruence between asthma medication use and doctor-diagnosed asthma is expected to increase with age. The aim of this study is to evaluate the relationship between prescribing of asthma medication and doctor-diagnosed asthma in children age 0-17. Methods. We studied all 74,580 children below 18 years of age, belonging to 95 GP practices within the second Dutch national survey of general practice (DNSGP-2), in which GPs registered all physician-patient contacts during the year 2001. Status on prescribing of asthma medication (at least one prescription for beta2-agonists, inhaled corticosteroids, cromones or montelukast) and doctor-diagnosed asthma (coded according to the International Classification of Primary Care) was determined. Results. In total 7.5% of children received asthma medication and 4.1% had a diagnosis of asthma. Only 49% of all children receiving asthma medication was diagnosed as an asthmatic. Subgroup analyses on age, gender and therapy groups showed that the Positive Predictive Value (PPV) differs significantly between therapy groups only. The likelihood of having doctor-diagnosed asthma increased when a child received combination therapy of short acting beta2-agonists and inhaled corticosteroids (PPV = 0.64) and with the number of prescriptions (3 prescriptions or more, PPV = 0.66). Both prescribing of asthma medication and doctor-diagnosed asthma declined with age but the congruence between the two measures did not increase with age. Conclusion. In this study, less than half of all children receiving asthma medication had a registered diagnosis of asthma. Detailed subgroup analyses show that a diagnosis of asthma was present in at most 66%, even in groups of children treated intensively with asthma medication. Although age strongly influences the chance of being treated, remarkably, the congruence between prescribing of asthma medication and doctor-diagnosed asthma does not increase with age.