Trends in polypharmacy over 12 years and changes in its social gradients in South Korea

Polypharmacy is associated with adverse drug reactions and represents an economic burden on the health insurance system. The objective of our study was to assess the trends in polypharmacy and its associated factors in South Korea. This cross-sectional study used a nationwide sampled database between 2002 and 2013, including outpatients of all ages who received at least 1 prescription in the same period. Polypharmacy was defined as the concomitant prescription of ≥6 distinct medications on a single prescription at least once without a given duration. The yearly prescribing trends were calculated and plotted. We conducted comparative analyses to identify the changes in social gradients of polypharmacy between the first 2 years, 2002‒2003, and the final 2 years, 2012‒2013. We repeated logistic regressions for pediatrics </div

Changes in age-adjusted prevalence of polypharmacy and the mean number of medications per prescription between 2002 and 2013 in Korea.

Changes in age-adjusted prevalence of polypharmacy and the mean number of medications per prescription between 2002 and 2013 in Korea.</p

Baseline characteristics of outpatients in the Korea National Health Insurance Service–National Sample Cohort according to medication use in the first years of the study, 2002–2003, and the recent years of the study, 2012–2013.

Baseline characteristics of outpatients in the Korea National Health Insurance Service–National Sample Cohort according to medication use in the first years of the study, 2002–2003, and the recent years of the study, 2012–2013.</p

Study flowchart for 12-year polypharmacy trends and the comparative analysis of polypharmacy and non-polypharmacy between 2002–2003 and 2012–2013.

Polypharmacy was defined as ≥6 medications and non-polypharmacy as ≤5 medications, based on the maximum number of concomitantly prescribed medications.</p

Distributions of medication use (mean) by age and economic status, 2002–2003.

Economic status scale: 0 = most deprived and 10 = most affluent.</p

Logistic regression model of the association between participant characteristics and polypharmacy (≥6 medications) in 2002–2003 and 2012–2013.

Logistic regression model of the association between participant characteristics and polypharmacy (≥6 medications) in 2002–2003 and 2012–2013.</p

Changes in the prevalence of polypharmacy in pediatrics and adolescents (<20 years of age) and in adults and the elderly (≥20 years of age) between 2002 and 2013.

Changes in the prevalence of polypharmacy in pediatrics and adolescents (<20 years of age) and in adults and the elderly (≥20 years of age) between 2002 and 2013.</p

Distributions of medication use (mean) by age and economic status, 2012–2013.

Economic status scale: 0 = most deprived and 10 = most affluent.</p

Subgroup analysis for differences in characteristics associated with completeness scores by profession, restricted to reports from manufacturers.

Subgroup analysis for differences in characteristics associated with completeness scores by profession, restricted to reports from manufacturers.</p

Study flow diagram describing reports of adverse drug reactions and their combinations.

Study flow diagram describing reports of adverse drug reactions and their combinations.</p