Trends in Prevalence and Determinants of Potentially Inappropriate Prescribing in the United States: 2007 to 2012.
OBJECTIVE
To estimate the prevalence and determinants of the use of potentially inappropriate medications (PIMs) in older U.S. adults using the 2012 Beers criteria.


METHODS
Retrospective cohort study in a random national sample of Medicare beneficiaries.


METHODS
Fee-for-service Medicare beneficiaries from 2007 to 2012.


METHODS
U.S. population aged 65 and older with Parts A, B, and D enrollment in at least 1 month during a calendar year (N = 38,250 individuals; 1,308,116 observations).


METHODS
The 2012 Beers criteria were used to estimate the prevalence of the use of PIMs in each calendar month and over a 12-month period using data on diagnoses or conditions present in the previous 12 months. Generalized estimating equations were used to account for the dependence of multiple monthly observations of a single person when estimating 95% confidence intervals (CIs), and logistic regression was used to identify independent determinants of PIM use.


RESULTS
The point prevalence of the use of PIMs decreased from 37.6% (95% CI = 37.0-38.1) in 2007 to 34.2% (95% CI = 33.6-34.7) in 2012, with a statistically significant 2% (95% CI = 1-3%) decline per year assuming a linear trend. The 1-year period prevalence declined from 64.9% in 2007 to 56.6% in 2012. The strongest predictor of PIM use was the number of drugs dispensed. Individuals aged 70 and older and those seen by a geriatrician were less likely to receive a PIM.


CONCLUSIONS
From 2007 to 2012, the prevalence of PIM use in older U.S. adults decreased according to the 2012 Beers criteria, although it remains high, still affecting one-third each month and more than half over 12 months. The number of dispensed prescriptions could be used to target future interventions.
Farmacia Clínica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile.|Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill, North Carolina.
Marcela
M
Jirón
Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill, North Carolina.
Virginia
V
Pate
Division of Geriatric Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina.
Laura C
LC
Hanson
Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill, North Carolina.
Jennifer L
JL
Lund
Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill, North Carolina.
Michele
M
Jonsson Funk
Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill, North Carolina.
Til
T
Stürmer
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D057970:Inappropriate Prescribing / Q000639:trends*; D008297:Male; D006278:Medicare; D010818:Practice Patterns, Physicians' / Q000639:trends*; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States
Beers criteria; Medicare; database study; older adults; pharmacoepidemiology; potentially inappropriate medications