OBJECTIVES

: We evaluated the prevalence of price changes associated with drug shortages in the United States (US), and further assessed how price changes differed with the number of manufacturers supplying each drug.

METHODS

: Using the US Food and Drug Administration website, we identified all drug shortages active in the US as of December 2015 and December 2016, and extracted national drug codes (NDC) and shortage start dates. Using 2005-2016 pricing data from AnalySource, we extracted the monthly wholesale acquisition cost (WAC) for each NDC in the month of shortage initiation, 12 months before, and 12 months after. Our final sample included 617 NDCs for 90 drugs. We constructed an interrupted time-series analysis with a linear mixed model regressing the monthly relative difference in WAC against fixed effects for time, period after shortage initiation, the supply of each drug by >3 manufacturers, the two second-order interactions between these effects, the third-order interaction between the 3 of them, route of administration, and a random effect for drug.

RESULTS

: Prices increased 6.3% in the year before the shortage, but 18.0% in the year after shortage initiation. Prices of drugs supplied by ≤3 manufacturers increased 3 times faster after shortage initiation: from 9.6% in the year before to 31.6% in the year after. Among drugs supplied by >3 manufacturers, the rate of increase doubled from 2.6% in the year before to 5.2% in the year after. Mixed models showed that WACs increased significantly faster after shortage initiation (p-value for trend change<0.001), but the shortage effect did not differ between drugs supplied by ≤3 vs. >3 manufacturers (p-value=0.927).

CONCLUSIONS

: Among drugs experiencing shortages in 2015 and 2016, list prices increased significantly faster in the year after the start of a shortage than in the year before. Prescription drug shortages require greater attention from policymakers.