title: Changes in office visit use associated with electronic messaging and telephone encounters among patients with diabetes in the PCMH.
abstract: OBJECTIVE
  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.
authors.affiliation: Division of General Internal Medicine and Geriatrics, Northwestern University Fein-berg School of Medicine, Chicago, Illinois Group Health Research Institute, Seattle, Washington david.liss@northwestern.edu.
authors.forename: David T
authors.initials: DT
authors.lastname: Liss
authors.affiliation: Group Health Research Institute, Seattle, Washington Department of Health Services, University of Washington School of Public Health, Seattle, Washington.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Reid
authors.affiliation: Group Health Research Institute, Seattle, Washington Department of Health Services, University of Washington School of Public Health, Seattle, Washington.
authors.forename: David
authors.initials: D
authors.lastname: Grembowski
authors.affiliation: Group Health Research Institute, Seattle, Washington Department of Health Services, University of Washington School of Public Health, Seattle, Washington Department of Biostatistics, University of Washington School of Public Health, Seattle, Washington.
authors.forename: Carolyn M
authors.initials: CM
authors.lastname: Rutter
authors.affiliation: Group Health Research Institute, Seattle, Washington.
authors.forename: Tyler R
authors.initials: TR
authors.lastname: Ross
authors.affiliation: Group Health Research Institute, Seattle, Washington Department of Health Services, University of Washington School of Public Health, Seattle, Washington.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Fishman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003142:Communication; D003920:Diabetes Mellitus / Q000628:therapy*; D034742:Electronic Mail; D005260:Female; D006801:Humans; D020407:Internet; D065186:Interrupted Time Series Analysis; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009819:Office Visits / Q000706:statistics & numerical data*; D018802:Patient-Centered Care / Q000706:statistics & numerical data* / Q000639:trends; D017216:Telemedicine / Q000706:statistics & numerical data*; D013689:Telephone / Q000706:statistics & numerical data*; D055815:Young Adult
keywords: communication; electronic mail; family practice; health services needs and demand; office visits; practice redesign; practice-based research; primary care; telephone; utilization