Changes in Office Visit Use Associated With Electronic Messaging and Telephone Encounters Among Patients With Diabetes in the PCMH

PURPOSE Telephone- and Internet-based communication are increasingly common in primary care, yet there is uncertainty about how these forms of communication affect demand for in-person office visits. We assessed whether use of copay-free secure messaging and telephone encounters was associated with office visit use in a population with diabetes. METHODS We used an interrupted time series design with a patient-quarter unit of analysis. Secondary data from 2008–2011 spanned 3 periods before, during, and after a patient-centered medical home (PCMH) redesign in an integrated health care delivery system. We used linear regression models to estimate proportional changes in the use of primary care office visits associated with proportional increases in secure messaging and telephone encounters. RESULTS The study included 18,486 adults with diabetes. The mean quarterly number of primary care contacts increased by 28% between the pre-PCMH baseline and the postimplementation periods, largely driven by increased secure messaging; quarterly office visit use declined by 8%. In adjusted regression analysis, 10% increases in secure message threads and telephone encounters were associated with increases of 1.25% (95% CI, 1.21%–1.29%) and 2.74% (95% CI, 2.70%–2.77%) in office visits, respectively. In an interaction model, proportional increases in secure messaging and telephone encounters remained associated with increased office visit use for all study periods and patient subpopulations (P <.001). CONCLUSIONS Before and after a medical home redesign, proportional increases in secure messaging and telephone encounters were associated with additional primary care office visits for individuals with diabetes. Our findings provide evidence on how new forms of patient-clinician communication may affect demand for office visits.