Impact of Patient Portal Use on Duplicate Laboratory Tests in Diabetes Management.

Background: Patients seek care across multiple health care settings. One coordination issue is the unnecessary duplication of laboratory across different health care settings. This analysis examined the association between patient portal use and duplication of laboratory testing among Veterans who are dual users of Veterans Affairs (VA) and non-VA providers. Materials and Methods: A national sample of Veterans who were newly authenticated users of the portal during fiscal year (FY) 2013 who used Blue Button at least once were compared with a random sample of Veterans who were not registered to use the portal. From these two groups, Veterans who were also Medicare-eligible users in FY2014 were identified. Duplicate testing was defined as receipt of more than five HbA1c (hemoglobin A1c) in 1 year. Results: Use of the Blue Button decreased the odds of duplicate HbA1c testing in VA and Medicare-covered facilities across three comparisons: (1) overall between users and nonusers: portal users were less likely to have duplicate testing; (2) pre-post comparison: there was a trend toward lower duplicate testing in both groups across time; and (3) pre-post comparisons accounting for use of the portal: the trend toward lower duplicate testing was greater in Blue Button users. Conclusion: Duplicate HbA1c testing was significantly lower in dual users of VA and Medicare services who used the Blue Button feature of their VA patient portal. Non-VA providers encounter barriers to access of complete information about Veterans who also use VA health care. Provider endorsement of consumer-mediated health information exchange could help further this model of sharing information.