Regional variation in healthcare usage for Medicare beneficiaries: a cross-sectional study based on the health and retirement study

OBJECTIVES: To investigate whether regional variation changes with different beneficiary health insurance coverage types. DESIGN: A cross-sectional study of the Health and Retirement Study (HRS) in 2018 was used. SETTING: Medicare beneficiaries only covered by Medicare (group 1) are compared with those covered by Medicare and other health insurance (group 2). Outcomes included healthcare usage measures: (1) whether beneficiaries have a hospital stay and (2) the number for those with at least one stay; (3) whether beneficiaries have a doctor’s visit and (4) the number for those with at least one visit. We compared healthcare usage in both groups across the five regions: (1) New England and Mid-Atlantic; (2) East North Central and West North Central; (3) South Atlantic; (4) East South Central and West South Central; (5) Mountain and Pacific. We used logistic regression for binary outcomes and negative binomial regression for count outcomes in each group. PARTICIPANTS: We identified 8749 Medicare beneficiaries, of which 4098 in group 1 and 4651 in group 2. RESULTS: Residents in all non-reference regions had a significantly lower probability of seeking a doctor’s visit in group 1 (OR with 95% CI 0.606 (0.374 to 0.982), 0.619 (0.392 to 0.977), 0.472 (0.299 to 0.746) and 0.618 (0.386 to 0.990) in the order of above regions, respectively), which is not significant in group 2. Residents in most non-reference regions (except South Atlantic) had a significantly fewer number of seeking a hospital stay in group 2 (incident rate ratio (IRR) with 95% CI 0.797 (0.691 to 0.919), 0.740 (0.643 to 0.865), 0.726 (0.613 to 0.859) in the order of above regions, respectively), which is not significant in group 1. CONCLUSION: Regional variation in the likelihood of having a doctor’s visit was reduced in Medicare beneficiaries covered by supplemental health insurance. Regional variation in hospital stays was accentuated among Medicare beneficiaries covered by supplemental health insurance.