The Nordic prescription databases as a resource for pharmacoepidemiological research--a literature review.

PURPOSE: All five Nordic countries have nationwide prescription databases covering all dispensed drugs, with potential for linkage to outcomes. The aim of this review is to present an overview of therapeutic areas studied and methods applied in pharmacoepidemiologic studies using data from these databases. METHODS: The study consists of a Medline-based structured literature review of scientific papers published during 2005-2010 using data from the prescription databases in Denmark, Finland, Iceland, Norway, and Sweden, covering 25 million inhabitants. Relevant studies were analyzed in terms of pharmacological group, study population, outcomes examined, type of study (drug utilization vs. effect of drug therapy), country of origin, and extent of cross-national collaboration. RESULTS: A total of 515 studies were identified. Of these, 262 were conducted in Denmark, 97 in Finland, 4 in Iceland, 87 in Norway, and 61 in Sweden. Four studies used data from more than one Nordic country. The most commonly studied drugs were those acting on the nervous system, followed by cardiovascular drugs and gastrointestinal/endocrine drugs. A total of 228 studies examined drug utilization and 263 focused on the effects and safety of drug therapy. Pregnant women were the most commonly studied population in safety studies, whereas prescribers' adherence to guidelines was the most frequent topic of drug utilization studies. CONCLUSIONS: The Nordic prescription databases, with their possibility of record-linkage, represent an outstanding resource for assessing the beneficial and adverse effects of drug use in large populations, under routine care conditions, and with the potential for long-term follow-up.

Impact of out-of-pocket expenses on discontinuation of statin therapy: a cohort study in Finland.

WHAT IS KNOWN AND OBJECTIVE: Out-of-pocket expenses of drug therapy may negatively affect adherence. We aimed to analyse 1-year discontinuation rates between cohorts initiating therapy with either generic simvastatin or non-generic atorvastatin. METHODS: Statin-naìve initiators of atorvastatin and generic simvastatin in April-June 2003, and corresponding cohorts in 2005, were identified through the nationwide Finnish prescription register. Persistence with statin therapy was followed for 365 days, considering the treatment to have been discontinued when the tablet-free gap between two consecutive refills exceeded 90 days. Using multivariate-adjusted logistic regression, odds ratios (OR) for discontinuation associated with initiating with simvastatin vs. atorvastatin were estimated separately for each year. RESULTS AND DISCUSSION: In the year 2003, 5838 persons initiated treatment with atorvastatin and 5644 with generic simvastatin. In the year 2005, the respective numbers were 5228 and 10 987. Soon after the introduction of generic substitution in 2003, there was no difference in the risk of discontinuation between the comparator groups [OR 0·97, 95% confidence interval (CI) 0·89-1·05]. Two years later, persons initiating with generic simvastatin were 20% less likely to discontinue statin therapy (OR 0·80; 95% CI 0·74-0·83). Among persons whose medicinal costs were almost completely reimbursed towards the end of the initiation year, the OR was 1·14 (95% CI 0·76-1·64, P = 0·033 for interaction). WHAT IS NEW AND CONCLUSIONS: We found that lower out-of-pocket expenses associated with the initiating statin had a positive impact on persistence with therapy. The finding does not seem to apply to persons with minor copayments towards the end of the initiation year.

Adoption of celecoxib and rofecoxib: a nationwide database study.

BACKGROUND AND OBJECTIVE: Cyclooxygenase 2-selective non-steroidal anti-inflammatory drugs (NSAIDs, coxibs) are recommended primarily for patients at high risk of gastrointestinal bleeding, most of them being elderly. Our objective was to describe and analyse patient- and physician-related factors affecting the adoption of celecoxib and rofecoxib 2 years after their launch in Finland. METHODS: Retrospective analysis of the nationwide Prescription Register. Physicians who had issued at least 200 reimbursed prescriptions in 2002 (n = 12 033, 80% of working-age Finnish physicians) were involved in the analysis. RESULTS AND DISCUSSION: Excluding patients with rheumatoid arthritis (RA), almost one-fifth (18%) of NSAIDs prescriptions were for coxibs. In patients with RA the share was 25%. The share of coxib prescriptions of all NSAIDs increased with age of the patient. Over one half (58%) of coxib prescriptions were issued for patients under 65 years of age. Specialists in physical and rehabilitation medicine were the fastest adopters of coxibs: one-third of their NSAID prescriptions in 2002 were for coxibs. Primary care physicians were the most conservative both in adopting and favouring coxibs. CONCLUSIONS: Coxibs have gained the status of standard prescription NSAIDs within a few years. Their use should be restricted to patients who could benefit most from the use. Routine prescribing of expensive new drugs increases the drug bill without additional health gain.

Parasomnias decline during pregnancy.

OBJECTIVES: A survey of the effects of pregnancy on parasomnias. MATERIAL AND METHODS: In an area of a central hospital and the maternity care units in the nearby rural community, women were interviewed during and after their pregnancy with a series of five questionnaires to assess the frequency of their parasomnias. The first questionnaire covered the 3 months before becoming pregnant, the next three the trimesters of pregnancy and the last one the 3 months after delivery. Altogether 325 mothers filled all the five questionnaires and constitute the study group. RESULTS: The total number of parasomnias declined (P < 0.001) during pregnancy and even more among the primiparas than among the multiparas (difference until third trimester, P=0.02). Among various parasomnias reported, sleep talking and sleepwalking decreased from the prepregnant period to the second trimester (22.8 vs 12.6%, change P=0.003), and the reported sleep starts also diminished from the prepregnant time to the first trimester (78.5 vs 63.1%, P < 0.001), but these phenomena did not change further during the follow-up. Altogether 55.7% of the women reported having nightmares 3 months before the pregnancy, and 47.7, 49.5, 41.2 and 40.3% (change from the prepregnant period, P < 0.001), respectively, at first, second and third trimester and after the delivery. Reported hypnagogic hallucinations decreased from the prepregnant time to the first trimester (9.8 vs 6.5%, P=0.027), but returned thereafter to the previous level. During the prepregnant period, 25.8% of the women reported bruxism and only 19.9% during the first trimester (P=0.009). Though the prevalence of sleep paralysis decreased during the first trimester of pregnancy, it was the only parasomnia that increased during later pregnancy (from 5.7 to 13.3% in the second trimester, P < 0.013). CONCLUSIONS: The reported frequency of most parasomnias decreases during pregnancy and even more in primiparas than multiparas.