title: Sustained Use of Patient Portal Features and Improvements in Diabetes Physiological Measures.
abstract: Personal health records (PHRs) have the potential to improve patient self-management for chronic conditions such as diabetes. However, evidence is mixed as to whether there is an association between PHR use and improved health outcomes.
  
  
  
  The aim of this study was to evaluate the association between sustained use of specific patient portal features (Web-based prescription refill and secure messaging-SM) and physiological measures important for the management of type 2 diabetes.
  
  
  
  Using a retrospective cohort design, including Veterans with diabetes registered for the My Health e Vet patient portal who had not yet used the Web-based refill or SM features and who had at least one physiological measure (HbA1c, low-density lipoprotein (LDL) cholesterol, blood pressure) in 2009-2010 (baseline) that was above guideline recommendations (N=111,686), we assessed portal use between 2010 and 2014. We calculated the odds of achieving control of each measure by 2013 to 2014 (follow-up) by years of using each portal feature, adjusting for demographic and clinical characteristics associated with portal use.
  
  
  
  By 2013 to 2014, 34.13% (38,113/111,686) of the cohort was using Web-based refills, and 15.75% (17,592/111,686) of the cohort was using SM. Users were slightly younger (P<.001), less likely to be eligible for free care based on economic means (P<.001), and more likely to be women (P<.001). In models adjusting for both features, patients with uncontrolled HbA1c at baseline who used SM were significantly more likely than nonusers to achieve glycemic control by follow-up if they used SM for 2 years (odds ratio-OR=1.24, CI: 1.14-1.34) or 3 or more years (OR=1.28, CI: 1.12-1.45). However, there was no significant association between Web-based refill use and glycemic control. Those with uncontrolled blood pressure at baseline who used Web-based refills were significantly more likely than nonusers to achieve control at follow-up with 2 (OR=1.07, CI: 1.01-1.13) or 3 (OR=1.08, CI: 1.02-1.14) more years of Web-based refill use. Both features were significantly associated with improvements in LDL cholesterol levels at follow-up.
  
  
  
  Although rates of use of the refill function were higher within the population, sustained SM use had a greater impact on HbA1c. Evaluations of patient portals should consider that individual components may have differential effects on health improvements.
authors.affiliation: Center for Healthcare Organization and Implementation Research (CHOIR), Edith Nourse Rogers Memorial Veterans Hospital, Bedford, MA, United States. Stephanie.Shimada@va.gov.
authors.forename: Stephanie L
authors.identifier: 0000-0002-6517-5122
authors.initials: SL
authors.lastname: Shimada
authors.forename: Jeroan J
authors.identifier: 0000-0003-4472-2112
authors.initials: JJ
authors.lastname: Allison
authors.forename: Amy K
authors.identifier: 0000-0002-7539-7749
authors.initials: AK
authors.lastname: Rosen
authors.forename: Hua
authors.identifier: 0000-0002-6163-6550
authors.initials: H
authors.lastname: Feng
authors.forename: Thomas K
authors.identifier: 0000-0002-2909-4018
authors.initials: TK
authors.lastname: Houston
mesh_terms: D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis / Q000473:pathology / Q000628:therapy*; D005260:Female; D055991:Health Records, Personal; D006801:Humans; D008297:Male; D008875:Middle Aged; D000072638:Patient Portals; D012189:Retrospective Studies; D012648:Self Care / Q000379:methods*; D014481:United States; D014493:United States Department of Veterans Affairs / Q000458:organization & administration*; D014728:Veterans
keywords: HbA1c; blood pressure; cholesterol, LDL; diabetes mellitus, type 2; personal health records; self care; veterans