Volume 45 | Number 4 | August 2010

Abstract List

Anthony T. Lo Sasso, Mona Shah, Bianca K. Frogner


The impact of consumer‐driven health plans (CDHPs) has primarily been studied in a small number of large, self‐insured employers, but this work may not generalize to the wide array of firms that make up the overall economy. The goal of our research is to examine effects of health savings accounts (HSAs) on total, medical, and pharmacy spending for a large number of small and midsized firms.

Data Sources

Health plan administrative data from a national insurer were used to measure spending for 76,310 enrollees over 3 years in 709 employers. All employers began offering a HSA‐eligible plan either on a full‐replacement basis or alongside traditional plans in 2006 and 2007 after previously offering only traditional plans in 2005.

Study Design

We employ difference‐in‐differences generalized linear regression models to examine the impact of switching to HSAs.

Data Extraction Methods

Claims data were aggregated to enrollee‐years.

Principal Findings

For total spending, HSA enrollees spent roughly 5–7 percent less than non‐HSA enrollees. For pharmacy spending, HSA enrollees spent 6–9 percent less than traditional plan enrollees. More of the spending decrease was observed in the first year of enrollment.


Our findings are consistent with the notion that CDHP benefit designs affect decisions that are at the discretion of the consumer, such as whether to fill or refill a prescription, but have less effect on care decisions that are more at the discretion of the provider.