title: Glycemic control associated with secure patient-provider messaging within a shared electronic medical record: a longitudinal analysis.
abstract: OBJECTIVE
  To study differences in glycemic control and HbA1c testing associated with use of secure electronic patient-provider messaging. We hypothesized that messaging use would be associated with better glycemic control and a higher rate of adherence to HbA1c testing recommendations.
  
  
  METHODS
  Retrospective observational study of secure messaging at Group Health, a large nonprofit health care system. Our analysis included adults with diabetes who had registered for access to a shared electronic medical record (SMR) between 2003 and 2006. We fit log-linear regression models, using generalized estimating equations, to estimate the adjusted rate ratio of meeting three indicators of glycemic control (HbA1c <7%, HbA1c <8%, and HbA1c >9%) and HbA1c testing adherence by level of previous messaging use. Multiple imputation and inverse probability weights were used to account for missing data.
  
  
  RESULTS
  During the study period, 6,301 adults with diabetes registered for access to the SMR. Of these individuals, 74% used messaging at least once during that time. Frequent use of messaging during the previous calendar quarter was associated with a higher rate of good glycemic control (HbA1c <7%: rate ratio, 1.26 [95% CI, 1.15-1.37]) and a higher rate testing adherence (1.20 [1.15-1.25]).
  
  
  CONCLUSIONS
  Among SMR users, recent and frequent messaging use was associated with better glycemic control and a higher rate of HbA1c testing adherence. These results suggest that secure messaging may facilitate important processes of care and help some patients to achieve or maintain adequate glycemic control.
authors.affiliation: Department of Health Services, University of Washington School of Public Health, Seattle, Washington, USA. lynneharris@outlook.com
authors.forename: Lynne T
authors.initials: LT
authors.lastname: Harris
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Koepsell
authors.forename: Sebastien J
authors.initials: SJ
authors.lastname: Haneuse
authors.forename: Diane P
authors.initials: DP
authors.lastname: Martin
authors.forename: James D
authors.initials: JD
authors.lastname: Ralston
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000502:physiology; D003920:Diabetes Mellitus; D057286:Electronic Health Records; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care; D012189:Retrospective Studies
chemical_list: D001786:Blood Glucose