Hugo M. Smeets

Thiopurines prevent advanced colorectal neoplasia in patients with inflammatory bowel disease

Background and aims Previous studies have suggested a chemopreventive effect of 5-aminosalicylic acid (5-ASA) therapy in patients with inflammatory bowel disease (IBD). This effect has not been reported in IBD patients using thiopurines. We investigated the association between thiopurine or 5-ASA use and the risk of advanced neoplasia (AN), including high-grade dysplasia and colorectal cancer, in a large cohort of patients with IBD in the Netherlands. Methods PALGA, the nationwide network and registry of histo- and cytopathology in The Netherlands was linked to an anonymised computerised database of a Dutch health insurance company to identify patients with IBD with or without AN. Pharmaceutical data, including type and duration of medication use, were collected between January 2001 and December 2009. Cox proportional hazard regression analysis was used to calculate risk of AN in patients with and without thiopurine or 5-ASA use. Results A total of 2578 patients with IBD were included. Of these, 973 patients (38%) used 5-ASA, 314 (12%) thiopurines, 456 (18%) both 5-ASA and thiopurines and 835 (32%) none of these drugs. Twenty-eight patients (1%) developed AN during 16 289 person-years of follow-up. Of these, 11 patients (39%) had used 5-ASA, two (7%) thiopurines and one (4%) both drugs. Thiopurine use was associated with a significantly decreased risk of developing AN (adjusted HR 0.10, 95% CI 0.01 to 0.75). 5-ASA therapy also had a protective effect on developing AN, but this was not statistically significant (adjusted HR 0.56, 95% CI 0.22 to 1.40). Conclusion Thiopurine use protects IBD patients against the development of AN. The effect of 5-ASA appeared to be less pronounced.

Routine health insurance data for scientific research: potential and limitations of the Agis Health Database

OBJECTIVE Observational studies performed within routine health care databases have the advantage of their large size and, when the aim is to assess the effect of interventions, can offer a completion to randomized controlled trials with usually small samples from experimental situations. Institutional Health Insurance Databases (HIDs) are attractive for research because of their large size, their longitudinal perspective, and their practice-based information. As they are based on financial reimbursement, the information is generally reliable. STUDY DESIGN The database of one of the major insurance companies in the Netherlands, the Agis Health Database (AHD), is described in detail. Whether the AHD data sets meet the specific requirements to conduct several types of clinical studies is discussed according to the classification of the four different types of clinical research; that is, diagnostic, etiologic, prognostic, and intervention research. The potential of the AHD for these various types of research is illustrated using examples of studies recently conducted in the AHD. CONCLUSION HIDs such as the AHD offer large potential for several types of clinical research, in particular etiologic and intervention studies, but at present the lack of detailed clinical information is an important limitation.

Prescription patterns for psychotropic drugs in cancer patients; a large population study in the Netherlands

Psychotropic drugs are commonly prescribed for various psychological complaints in cancer patients. We aim to examine the prescription pattern in cancer patients of three common psychotropic drugs: benzodiazepine, antidepressant and antipsychotic.

Glucocorticosteroids associated with a decreased risk of psychosis.

The hypothesis that chronic inflammation may play a role in psychosis receives increasing attention. In this study, we aim to investigate whether the use of steroidal anti-inflammatory drugs is associated with a decreased risk of psychosis. A longitudinal nested case-control study was performed investigating the association of glucocorticosteroid (GCS) consumption with a new diagnosis of a psychotic disorder. Significantly reduced odds ratios of 0.52 (95% confidence interval, 0.36-0.75) were found for GCS in men only (odds ratio in women, 0.84 [95% confidence interval, 0.590-1.20]). Similar risk reductions were present for the inhaled and systemic GCSs. A dose-response relationship was present. Our finding of an inverse relation between GCS consumption and new psychotic episodes may promote further research into inflammation in schizophrenia.

What factors explain the differences in morbidity estimations among general practice registration networks in the Netherlands? A first analysis

Background: Information on the incidence and prevalence of diseases is a core indicator for public health. There are several ways to estimate morbidity in a population (e.g., surveys, healthcare registers). In this paper, we focus on one particular source: general practice based registers. Dutch general practice is a potentially valid source because nearly all non-institutionalized inhabitants are registered with a general practitioner (GP), and the GP fulfils the role as “gatekeeper”. However, there are some unexplained differences among morbidity estimations calculated from the data of various general practice registration networks (GPRNs). Objective: To describe and categorize factors that may explain the differences in morbidity rates from different GPRNs, and to provide an overview of these factors in Dutch GPRNs. Results: Four categories of factors are distinguished: “healthcare system”, “methodological characteristics”, “general practitioner”, and “patient”. The overview of 11 Dutch GPRNs reveals considerable differences in factors. Conclusion: Differences in morbidity estimation depend on factors in the four categories. Most attention is dedicated to the factors in the “methodology characteristics” category, mainly because these factors can be directly influenced by the GPRN.

Risk of Nonmelanoma Skin Cancer in Patients With Inflammatory Bowel Disease Who Use Thiopurines Is Not Increased

0.94 (0.58–1.50) 0.85 (0.51–1.41) Presence of ulcerative colitis 1.08 (0.69–1.67) 0.62 (0.40–0.98) Female gender 0.45 (0.29–0.69) 0.47 (0.30–0.74) Increasing age, y 1.06 (1.05–1.07) 1.06 (1.04–1.08) Duration of IBD, mo 1.01 (1.00–1.01) 1.00 (1.00–1.01) HR, hazard ratio; 95% CI, 95% confidence interval. a Adjusted for all the covariates listed in the table.

A comorbid anxiety disorder does not result in an excess risk of death among patients with a depressive disorder

BACKGROUND Several studies have demonstrated increased mortality associated with depression and with anxiety. Mortality due to comorbidity of two mental disorders may be even more increased. Therefore, we investigated the mortality among patients with depression, with anxiety and with both diagnoses. METHODS By linking the longitudinal Psychiatric Case Register Middle-Netherlands, which contains all patients of psychiatric services in the Utrecht region, to the death register of Statistics Netherlands, hazard ratios of death were estimated overall and for different categories of death causes separately. RESULTS We found an increased risk of death among patients with an anxiety disorder (N=6919): HR=1.45 (95%CI: 1.25-1.69), and among patients with a depression (N=14,778): HR=1.83, (95%CI: 1.72-1.95), compared to controls (N=103,824). The hazard ratios among both disorders combined (N=4260) were similar to those with only a depression: HR=1.91, (95% CI: 1.64-2.23). Among patients with a depression, mortality across all important disease-related categories of death causes (neoplasms, cardiovascular, respiratory, and other diseases) and due to suicide was increased, without an excess mortality in case of comorbid anxiety. LIMITATIONS The presented data are restricted to broad categories of patients in specialist services. No data on behavioral or intermediate factors were available. CONCLUSIONS Although anxiety is associated with an increased risk of death, the presence of anxiety as comorbid disorder does not give an additional increase in the risk of death among patients with a depressive disorder. The increased mortality among patients with depression is not restricted to suicide and cardiovascular diseases, but associated with a broad range of death causes.

Trends and determinants of adequate gastroprotection in patients chronically using NSAIDs

To identify determinants and trends of gastroprotection in patients chronically using NSAIDs.

The Psychiatric Case Register Middle Netherlands

BackgroundThe Psychiatric Case Register Middle Netherlands (PCR-MN) registers the mental healthcare consumption of over Dutch 760,000 inhabitants in the centre of the Netherlands. In 2010 the follow-up period was over ten years. In this paper we describe the content, aims and research potential of this case register.DescriptionAll mental healthcare institutions in the middle-western part of the province of Utrecht participate in the PCR-MN case register. All in- and out-patients treated in these institutions have been included in the database from the period 2000 to 2010. Diagnosis according to DSM-IV on axis I to IV, visits to in- and out-patient clinics and basic demographics are recorded. A major advantage of this register is the possibility to link patients anonymously from the PCR-MN cohort to other databases to analyze relationships with determinants and outcomes, such as somatic healthcare consumption, mortality, and demographics, which further increases the research potentialConclusionsThe PCR-MN database has a large potential for scientific research because of its size, duration of follow-up and ability to link with additional databases, and is accessible for academic researchers.

Psychosis and suicide risk by ethnic origin and history of migration in the Netherlands.

BACKGROUND There is an increased incidence of non-affective psychotic disorders (NAPD) among first- and second-generation migrants in Europe. The purpose of this population-based study was to compare the risk of suicide in Dutch natives and immigrants with or without NAPD. METHODS Cases of NAPD (n=12 580) from three Dutch psychiatric registers were linked to the cause of death register of Statistics Netherlands and were compared to matched controls (n=244 792) from the population register, who had no such diagnosis. Hazard ratios (HRs) of suicide were estimated and adjusted for age and gender by Cox regression analysis. RESULTS The presence of NAPD was strongly associated with suicide risk in each ethnic group. However, for all ethnic minority groups the HRs were somewhat lower than among Dutch natives, for whom the HR was 23.4 (95%-CI; 18.5-29.7). A closer examination revealed that suicide risk was influenced by the history of migration. While the risk for immigrants of the first generation, diagnosed with NAPD, was significantly lower than that for native Dutch patients (HR=0.45; 95%-CI: 0.28-0.73), the risk for those of the second generation was more similar to that for the Dutch (HR=0.85; 95%-CI: 0.51-1.40) (P value of history of migration=0.005). CONCLUSION Immigrants diagnosed with NAPD of the first generation appear to be protected against suicide, whereas this protection is waning among those of the second generation. This is the first study worldwide on suicide in migrants with NAPD and the first study of suicide in patients with NAPD in the Netherlands.