Insurance Transitions and Changes in Physician and Emergency Department Utilization: An Observational Study

Publication Name: 
Journal of General Internal Medicine
Publication Authors: 
Barnett ML, Song Z, Rose S, Bitton A, Chernew ME, Landon BE
HCP Authors:Sherri Rose PhD, Asaf Bitton MD, MPH, Michael E. Chernew PhD, Bruce Landon MD, MBA, MSC
Date of Publication: 
May 2017



Shopping for health insurance is encouraged as a way to find the most affordable coverage that best meets an enrollee's needs. However, the extent to which individuals switch insurance and subsequent changes in health care utilization that might arise, particularly new physician visits, are not well understood.


To examine the relationship between insurance switching and new physician and emergency department visits around the time of a switch.


Observational study using a difference-in-differences design to compare those switching insurance carriers with propensity score-matched controls who did not switch, stratified based on whether individuals initially had private or Medicaid insurance coverage. All analyses adjusted for individual and insurance characteristics.


Continuously insured, non-elderly individuals with private or Medicaid insurance coverage in Massachusetts from 2010 to 2013.


Rates of new primary care and specialist physician visits, as well as rates of emergency department visits.


Before matching, among 1,628,057 continuously insured individuals, 418,231 (26%) switched insurance carriers during a 2-year period. Characteristics of switchers and non-switchers were similar after matching (n = 316,343 in each group). After matching, switching plans was associated with a 203% and 47.5% increase in the rate of new primary care physician visits following switching for those initially with Medicaid or private coverage, respectively (both p < 0.001), with a large short-term increase, diminishing over time. Among those with Medicaid coverage, switching was associated with a 14.9% higher rate of ED visits during the month of switching (p < 0.001), but otherwise decreased modestly after switching.


Insurance switching is common, and is associated with increased new physician visits and temporarily increased ED use among the publicly insured. As insurance markets become more volatile in the current policy environment, understanding changes in utilization after insurance switching may become increasingly important.


emergency department utilization; health insurance; insurance exchanges; primary care utilization

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