Accuracy of annual prescription drug expenditure forecasts in AJHP.

American journal of health-system pharmacy : AJHP : official journal of the American Society of Health-System Pharmacists

PubMedID: 26386105

Hartke PL, Vermeulen LC, Hoffman JM, Shah ND, Doloresco F, Suda KJ, Li EC, Matusiak LM, Hunkler RJ, Schumock GT. Accuracy of annual prescription drug expenditure forecasts in AJHP. Am J Health Syst Pharm. 2015;72(19):1642-8.
PURPOSE
The accuracy of the forecasts of drug expenditures in nonfederal hospitals and clinics published annually in the American Journal of Health-System Pharmacy (AJHP) relative to the accuracy of forecasts produced by the Centers for Medicare and Medicaid Services (CMS) was evaluated.

METHODS
AJHP-published forecasts of drug expenditure growth for nonfederal hospitals (for the years 2003 through 2013) and clinics (for the years 2004 through 2013) were compared with data on actual growth. Data on actual and projected growth published by CMS were analyzed for the years 2003 through 2012. The mean absolute error and directional accuracy of the forecasts published in AJHP for nonfederal hospitals and clinics and the CMS forecasts were determined and compared.

RESULTS
Actual spending growth was within the range of the forecast published in AJHP for 2 of 11 years for nonfederal hospitals and for 3 of 10 years for clinics; the forecasts for nonfederal hospitals and clinics were directionally accurate 27.3% and 60.0% of the time, respectively. The mean absolute errors of the AJHP-published drug expenditure forecasts for the nonfederal hospital and clinic sectors were 2.0 and 4.7 percentage points, respectively. The CMS forecasts of overall drug spending were directionally accurate 70% of the time, and the mean absolute error (2.2 percentage points) was not statistically different from that of either sector forecast published in AJHP.

CONCLUSION
The annual drug expenditure forecasts published in AJHP have been reasonably accurate for predicting growth in prescription expenditures when compared with other available drug expenditure forecasts.