Trends in Prescription Drug Use Among Adults in the United States From 1999-2012.
Level 4 - case-series / case-control
Serial cross-sectional observational survey data from NHANES.
PubMed 26529160 · doi:10.1001/jama.2015.13766
What was done
Researchers analyzed temporal trends in prescription drug use using nationally representative data from seven continuous NHANES cycles spanning 1999–2000 to 2011–2012. The study included 37,959 noninstitutionalized US adults aged 20 years and older (sample size per cycle: 4,861 to 6,212). Past 30-day prescription medication use overall and by drug class was assessed, and analyses were weighted to represent the civilian US adult population.
What was found
Overall prescription drug use increased from an estimated 51% in 1999–2000 to 59% in 2011–2012 (difference, 8% [95% CI, 3.8%–12%]; P for trend < .001). Polypharmacy (use of ≥5 prescription drugs) increased from 8.2% to 15% (difference, 6.6% [95% CI, 4.4%–8.2%]; P for trend < .001). Both trends remained statistically significant after adjusting for age. Among 18 drug classes used by >2.5% of the population, prevalence rose in 11 classes, including antihyperlipidemics, antidepressants, prescription proton-pump inhibitors, and muscle relaxants.
Why it matters
This study documents a substantial, population-level expansion in overall prescription medication burden and polypharmacy among US adults over a 12-year period, an increase not solely driven by an aging demographic.
Limits
The repeated cross-sectional design captures 30-day self-reported usage rather than continuous individual trajectories or adherence. The survey excluded institutionalized populations (such as nursing home residents), and the abstract does not report clinical indications, appropriateness of prescribing, or over-the-counter drug use.
Cited by
- supports Psychiatric drugs are the second or third most prescribed class of medications, following statins and gastrointestinal drugs.