Kajsa Kvist

Do antidepressants precipitate youth suicide?: a nationwide pharmacoepidemiological study.

The association between treatment with Selective serotonin reuptake inhibitors (SSRIs) and suicide in children and adolescents on the individual and ecological level were examined in a nationwide Danish pharmacoepidemiological register-linkage study including all persons aged 10–17 years treated with antidepressants during the period 1995–1999 (n=2,569) and a randomly selected control population (n=50,000). A tripartite approach was used. In Part 1, changes in youth suicide and use of antidepressants were examined. In Part 2, we made an assessment of youth suicide characteristics. In Part 3, we analysed the relative risk (RR) of suicide according to antidepressant treatment corrected for psychiatric hospital contact to minimize the problem of confounding by indication. The use of SSRIs among children and adolescents increased substantially during the study period, but the suicide rate remained stable (Part 1). Among 42 suicides nationally aged 10–17 years at death, none was treated with SSRIs within 2 weeks prior to suicide (Part 2). There was an increased rate of suicide associated with SSRIs (RR=4.47), however, not quite significant (95% CI: 0.95–20.96), when adjusted for severity of illness (Part 3). Conclusively, we were not able to identify an association between treatment with SSRIs and completed suicide among children and adolescents.

Structured home visits to older people. Are they only of benefit for women? A randomised controlled trial.

Objective – To investigate whether education of primary care professionals improved functional ability in home-dwelling older people, with special focus on gender differences. Design – A prospective controlled three-year follow-up study (1999–2001) with randomisation and intervention at municipality level and outcomes measured at individual level. Intervention municipality visitors received regular education and GPs were introduced to a short assessment programme. Control municipalities received no education but conducted the preventive programme in their own way. Setting – Primary care, 34 municipalities. Subjects – 5788 home-dwelling 75- and 80-year-olds were invited. 4060 (70.1%) participated: 2104 in 17 intervention- and 1956 in 17 matched control-municipalities. The main outcome measure was obtained from 3383 (95.6%) of 3540 surviving participants. Main outcome measure – Functional ability. Results – Municipality intervention in coordination with GPs was associated with better functional ability in women (OR: 1.26; CI95: 1.08–1.47, p=0.004), but not in men (OR: 1.04; CI95: 1.85–1.27). Accepting and receiving free preventive home visits was associated with better functional ability among women (OR: 1.36; CI95: 1.16–1.60, p=0.0002), but not among men (OR: 0.98; CI95: 0.80–1.21). Conclusion – A brief, feasible educational intervention for primary care professionals and to accept and receive preventive home visits may have effect in older women, but not in older men.

Temporal changes in suicide rates for persons treated and not treated with antidepressants in Denmark during 1995-1999

Objective:  To compare the temporal changes in suicide rate among patients treated with antidepressants with the change in suicide rate among persons who have not been treated with antidepressants during 1995–1999.

Do antidepressants prevent suicide

As in many developed countries, the use of antidepressants in Denmark has been substantially increasing during recent years, coinciding with a decreasing suicide rate. We aimed to investigate the relationship between treatment with antidepressants and suicide on individualized data from a nationwide study comprising an observational cohort study with linkage of registers of all prescribed antidepressants and recorded suicides in Denmark during the period 1995–99. A total of 438 625 patients who purchased at least one prescription of antidepressants and 1073 862 individuals from the general population were included in the study. Patients who continued treatment with selective serotonin reuptake inhibitors (SSRIs) (i.e. who purchased SSRIs twice or more) had a decreased rate of suicide compared with patients who purchased SSRIs once only [rate ratio (RR)=0.63; 95% confidence interval (CI)=0.56–0.71]. Furthermore, the rate of suicide decreased consistently with the number of prescriptions. Similarly, among patients treated with newer antidepressants other than SSRIs, the rate of suicide was decreased compared with the rate for patients who purchased other newer antidepressants once only (RR=0.70; 95% CI=0.52–0.94). Continued antidepressant treatment with SSRIs or other newer antidepressants is found to be associated with a reduced risk of suicide.

Treatment with antidepressants and lithium is associated with increased risk of treatment with antiparkinson drugs: a pharmacoepidemiological study

Objective: To estimate the risk for persons treated with antidepressants or lithium of subsequent treatment with antiparkinson drugs (APD). Methods: The Danish national prescription database supplied data on all persons who received antidepressants, lithium, or antidiabetics (first control group). A second control group was included comprising persons from the general population. Outcome was purchase of APD and the study period was 1995 to 1999. Results: In total, 1 293 789 persons were included. The rate ratio of treatment with APD after treatment with antidepressants was 2.27 (95% CI 2.14 to 2.42) for men and 1.50 (95% CI 1.43 to 1.58) for women. Figures for lithium were almost identical. Conclusion: Persons treated with antidepressants or lithium are at increased risk of subsequently treatment with APD, showing an association between anxiety/affective disorder and Parkinson’s disease.

Use of antiparkinsonian drugs in Denmark: Results from a nationwide pharmacoepidemiological study

The objective of the present study was to record the use of antiparkinsonian drugs (APD) in Denmark and discuss estimates of the incidence and prevalence rates of Parkinsons disease (PD). The main indication for treatment with APD is idiopathic PD. The use of APD is, therefore, an indicator of the epidemiology of PD and Parkinsonism. We used a drug tracer design, which previously has been found applicable in estimating the frequency of PD. From a national prescription database, all persons who purchased APD from 1995 to 2002 could be identified on an individual level. Results show an age‐standardized prevalence rate for APD purchase of 164.0 persons per 100,000, and an incidence rate of 55.9 persons per 100,000. The total number of persons purchasing APD was 11,656 per year on average. Our results showed higher figures of persons purchasing APD than the estimated prevalence of idiopathic PD in Denmark, which is approximately 100 persons per 100,000, corresponding to 5,000 to 6,000 persons. The differences might in part be explained by other indications for APD prescription in addition to PD and in part by misdiagnosis. However, the possibility of somewhat higher incidence and prevalence rates of PD than hitherto estimated should be considered.

Treatment with antiparkinson and antidepressant drugs: A register‐based, pharmaco‐epidemiological study

Depressive symptoms and major depression are frequent in patients with Parkinsons disease (PD). However, a systematic knowledge about the treatment with antidepressant drugs among PD patients is missing. We estimated the frequency of antidepressant drug treatment in a national sample of persons treated with antiparkinson drugs (APDs). All persons treated with APDs were identified in the national Danish Prescription database. The subsequent risk of treatment with antidepressants was estimated and compared with the risks for two large control groups. The study period was 5 years. In total, 1,029,737 persons were included. Persons who got APDs had significantly increased rate ratios (RR) of subsequent antidepressant drug treatment compared with an unexposed control group (RR: 2.10 (95% CI: 2.04–2.16)) and with persons who got anti‐diabetic drugs [RR: 1.58 (95% CI: 1.51–1.65)]. Persons treated with APDs have higher frequency of antidepressant drug treatment than have controls. With the reservation that data on drug consumption cannot be directly transferred into conclusions about specific diseases, the present study supports results from other population‐based studies of an association between PD and depression.

Repeated events and total time on test

We adopt the total time on test procedure to investigate monotone time trends in the intensity in a repeated event setting. The correct model is assumed to be a proportional hazards model, with a random effect to account for dependence within subjects. The method offers a simple routine for testing relevant hypotheses for recurrent event processes, without making distributional assumptions about the frailty. Such assumptions may severely affect conclusions concerning regression coefficients and cause bias in the estimated heterogeneity. The method is illustrated by re-analyzing Danish registry data and a long-term Swiss clinical study on recurrence in affective disorder.