Objective Despite emerging evidence that electronic health records (EHRs) can improve the efficiency and quality of medical care, most physicians in office practice in the United States do not currently use an EHR. We sought to measure the correlates of EHR adoption.

Design Mailed survey to a stratified random sample of all medical practices in Massachusetts in 2005, with one physician per practice randomly selected for survey.

Measurements EHR adoption rates.

Results The response rate was 71 percent (1345/1884). Overall, while 45 percent of physicians were using an EHR, EHRs were present in only 23 percent of practices. In multivariate analysis, practice size was strongly correlated with EHR adoption; 52 percent of practices with 7 or more physicians had an EHR, as compared with 14 percent of solo practices (adjusted odds ratio, 3.66; 95 percent confidence interval, 2.28 - 5.87). Hospital-based practices (adjusted odds ratio, 2.44; 95 percent confidence interval, 1.53 - 3.91) and practices that teach medical students or residents (adjusted odds ratio, 2.30; 95 percent confidence interval, 1.60 - 3.31) were more likely to have an EHR. The most frequently cited barriers to adoption were start-up financial costs (84 percent), ongoing financial costs (82 percent), and loss of productivity (81 percent).

Conclusions While almost half of physicians in Massachusetts are using an EHR, fewer than one in four practices in Massachusetts have adopted. Adoption rates are lower in smaller practices, those not affiliated with hospitals, and those that do not teach medical students or residents. Interventions to expand EHR use must address both financial and non-financial barriers, especially among smaller practices.