Characteristics and drug utilization patterns for heavy users of prescription drugs among the elderly: a Danish register-based drug utilization study.

Abstract

The objectives of this study were to (1) identify and characterize heavy users of prescription drugs among persons aged 60 years and above; (2) investigate the association of demographic, socioeconomic, and health-related variables with being a heavy drug user; and (3) study the most frequently used drugs among heavy drug users and development in use over time. This is a descriptive study. Heavy drug users were defined as the accumulated top 1 percentile who accounted for the largest share of prescription drug use measured in number of dispensed defined daily doses (DDDs). The nationwide Danish registers were used to obtain data. Multivariable logistic binary regression was used to determine which factors were associated with being a heavy drug user. Heavy drug users among persons aged 60 years and above accounted for 6.8, 6.0, and 5.5% of prescription drug use in 2002, 2007, and 2012, respectively. Male gender, those aged 60-69 years, being divorced, shorter education, low annual income, and recent hospitalization were all significantly associated with being in the top 1 percentile group of drug users (p < 0.05). The ten most frequently used drug classes among heavy drug users accounted for 75.4% of their use in 2012, and five of these were cardiovascular drugs. The development over time for the ten most used drug classes followed the same pattern among heavy drug users and in the general population. There is a skewed utilization of prescription drugs. Contrary to earlier findings, being male was associated with heavy prescription drug use both with respect to number of drugs used and drug expenditure.