Epidemiological measures of multiple drug use can be estimated from data in a prescription database. From a conceptual point of view, an estimator based on the number of simultaneously used drugs (calculated from the date of purchase and the number of DDD) is preferable, but the number of drugs purchased in a 3-month period may also be a useful estimator.

Early discontinuation is frequent in general practice, and patients of low social status are at greater risk. Adherence-promoting strategies should pay attention to the high prescribing doctors. Further studies may answer the question of whether the association between doctors' prescribing behaviour and early discontinuation is a feature specific to antidepressants or a more general phenomenon.

The registers used provided a comprehensive registry-based description of suicides' contacts with the health-care system. The most prominent features were the high prevalence of psychiatric morbidity and the high rate of contacts with GPs close to suicide.

This study showed that the use of ADs continues to increase because of the increase in the use of the new ADs. There was, however, still a considerable number of patients who started on TCA treatment in 1997. For repeated prescriptions, TCAs were used for longer times than SSRIs. In the very old, there was an apparently inappropriate high use of ADs.

Background: Biochemical liver function tests are widely used in the clinic and are some of the most frequently used tests in screening for diseases in older age groups. The aim of the present study was to estimate the relative importance of genetic and environmental factors to variations in these tests among the elderly. Methods: We conducted a survey among Danish twins, 73–102 years of age, identified in the population-based Danish Twin Registry. Among the 2749 individuals in the study population, an interview was conducted with 79%. From these, a blood sample was collected from 290 same-sex twin pairs, total of 580 subjects, within a 6-month period and analyzed for alanine aminotransferase (ALT), lactate dehydrogenase (LDH), γ-glutamyltransferase (GGT), bilirubin, and albumin. The interview included questions about alcohol consumption and body mass index (BMI; self-calculated height and weight). Heritability (proportion of the population variance attributable to genetic variation) was estimated using structural-equation analyses before and after correction for alcohol consumption and BMI. Results: Structural-equation analyses revealed a substantial heritability (35–61%) for the four biochemical liver function tests: ALT, GGT, LDH, and bilirubin. The remaining variation could be attributed to individuals’ nonfamilial environments. Adjustment for alcohol consumption and BMI had no influence on the heritability for ALT, GGT, LDH, and bilirubin. For albumin, two models fit equally well before adjustment for alcohol and BMI: a model including additive genetic and nonshared environmental factors (AE), and a model including shared and nonshared environmental factors (CE). After adjustment, the model including shared and nonshared environment was clearly the best fitting model. Conclusions: For both males and females, the effect of genetic factors on the biochemical liver function tests ALT, GGT, LDH, and bilirubin is substantial and accounts for one-third to two-thirds of the variation among individuals 73–102 years of age. The heritability is equal for males and females and does not change notably after controlling for alcohol consumption and BMI. For albumin, no major impact of genetic factors was found independent of BMI and alcohol consumption. An understanding of the genetic mechanisms underlying biochemical liver function tests among the very old may be of value in the interpretation of these tests in this age group.