Age and sex patterns of drug prescribing in a defined American population

Abstract

Objective: To describe the age and sex patterns of drug prescribing in Olmsted County, Minnesota.

Patients and methods: Population-based drug prescription records for the Olmsted County population in 2009 were obtained using the Rochester Epidemiology Project medical records linkage system (n=142,377). Drug prescriptions were classified using RxNorm codes and were grouped using the National Drug File-Reference Terminology.

Results: Overall, 68.1% of the population (n=96,953) received a prescription from at least 1 drug group, 51.6% (n=73,501) received prescriptions from 2 or more groups, and 21.2% (n=30,218) received prescriptions from 5 or more groups. The most commonly prescribed drug groups in the entire population were penicillins and β-lactam antimicrobials (17%; n=23,734), antidepressants (13%; n=18,028), opioid analgesics (12%; n=16,954), antilipemic agents (11%; n=16,082), and vaccines/toxoids (11%; n=15,918). However, prescribing patterns differed by age and sex. Vaccines/toxoids, penicillins and β-lactam antimicrobials, and antiasthmatic drugs were most commonly prescribed in persons younger than 19 years. Antidepressants and opioid analgesics were most commonly prescribed in young and middle-aged adults. Cardiovascular drugs were most commonly prescribed in older adults. Women received more prescriptions than men for several drug groups, in particular for antidepressants. For several drug groups, use increased with advancing age.

Conclusion: This study provides valuable baseline information for future studies of drug utilization and drug-related outcomes in this population.

Figure 1

Age-specific prevalence (per 100 population) of the 15 most commonly prescribed drug groups in men (boys) compared to women (girls). The 15 panels are in descending order of overall age- and sex-adjusted prevalence (see Table 1).

Figure 2

Prevalence (per 100 population) of the 10 most commonly prescribed drug groups in each age category. Overall prevalence is shown with the white bars, prevalence in men (boys) is shown with the blue bars, and prevalence in women (girls) is shown with the red bars.