Potential of prescription registries to capture individual-level use of aspirin and other nonsteroidal anti-inflammatory drugs in Denmark: trends in utilization 1999–2012

Abstract

BackgroundDue to over-the-counter availability, no consensus exists on whether adequate information on nonsteroidal anti-inflammatory drug (NSAID) use can be obtained from prescription registries.ObjectivesTo examine utilization of aspirin and nonaspirin NSAIDs in Denmark between 1999 and 2012 and to quantify the proportion of total sales that was sold on prescription.MethodBased on nationwide data from the Danish Serum Institute and the Danish National Prescription Registry, we retrieved sales statistics for the Danish primary health care sector to calculate 1-year prevalences of prescription users of aspirin or nonaspirin NSAIDs, and to estimate the corresponding proportions of total sales dispensed on prescription.ResultsBoth low-dose aspirin and nonaspirin NSAIDs were commonly used in the Danish population between 1999 and 2012, particularly among elderly individuals. The 1-year prevalence of prescribed low-dose aspirin increased throughout the study period, notably among men. Nonaspirin NSAID use was frequent in all age groups above 15 years and showed a female preponderance. Overall, the prevalence of prescribed nonaspirin NSAIDs decreased moderately after 2004, but substantial variation according to NSAID subtype was observed; ibuprofen use increased, use of all newer selective cyclooxygenase-2 inhibitors nearly ceased after 2004, diclofenac use decreased by nearly 50% after 2008, and naproxen use remained stable. As of 2012, the prescribed proportion of individual-level NSAID sales was 92% for low-dose aspirin, 66% for ibuprofen, and 100% for all other NSAIDs.ConclusionThe potential for identifying NSAID use from prescription registries in Denmark is high. Low-dose aspirin and nonaspirin NSAID use varied substantially between 1999 and 2012. Notably, use of cyclooxygenase-2 inhibitors nearly ceased, use of diclofenac decreased markedly, and naproxen use remained unaltered.

Diclofenac use and cardiovascular risks: series of nationwide cohort studies

“…The study had no missing data on exposure, confounders, or events. The prescription registry permitted identification of diclofenac use and is virtually complete 79. Our new user design resembled drug allocation in randomised controlled trials 24.…”

Frequency of cancer in patients operated on for acute peripheral arterial thrombosis and the impact on prognosis

“…In the same period, cardiovascular prophylactic medical treatment with antithrombotics and anticoagulation has increased. 22 This increased medical prophylaxis could explain the observed decline in acute thrombotic events. We do not, however, consider this a limitation, as this increased treatment has potentially benefited all groups.…”

Use of nonsteroidal anti-inflammatory drugs and risk of endometrial cancer: a nationwide case–control study

“…We had no information on drugs sold over-the-counter. However, during the study period, about 80-90 % of lowdose aspirin and non-aspirin NSAIDs were on prescription [28]. Furthermore, as 50 % of the cost of these drugs is reimbursed when they are prescribed by a physician, chronic use is by prescription in the majority of patients.…”

“…We added musculoskeletal disorders and headache to the full model, as proxy measures of over-the-counter analgesic use, and this analysis yielded risk estimates on nonaspirin NSAID use similar to the main analysis. In our study, we did not include high-dose aspirin in the analysis since it is mainly sold over-the-counter (90-95 %) [28]. However, in Denmark, high-dose aspirin is primarily used as short-term therapy for acute pains, and therefore, we assume that high-dose aspirin use resulted in only minor misclassification.…”

“…We did not include high-dose aspirin in the analyses because it is mainly sold over-thecounter (90 %) and used transiently for acute pains [28]. The Danish Prescription Registry holds information on all prescriptions redeemed at Danish pharmacies since 1995.…”