The Effect of Healthcare Provider Availability on Spine Spending

Spine conditions are costly and a major cause of disability. A growing body of evidence suggests that healthcare utilization and spending are driven by provider availability, which varies geographically and is a topic of healthcare policy debate.

To estimate the effect of provider availability on spine spending.

Retrospective cohort study using relocation as a natural experiment.

Fee-for-service Medicare beneficiaries over age 65 who relocated to a new hospital referral region between 2010 and 2014.

We used generalized linear models to evaluate how changes in per-beneficiary availability of three types of healthcare providers (primary care physicians, spine surgeons, and chiropractors) affected annual per-beneficiary spine spending. We evaluated increases and decreases in provider availability separately. To account for the relative sizes of the provider workforces, we also calculated estimates of the effects of changes in national workforce size on changes in national spine spending.

The association between provider availability and spending was generally stronger among beneficiaries who experienced a decrease (versus an increase) in availability. Of the three provider groups, spine surgeon availability was most strongly associated with spending. Among beneficiaries who experienced a decrease in availability, a decrease in one spine surgeon per 10,000 beneficiaries was associated with a decrease of $36.97 (95% CI: $12.51, $61.42) in annual spending per beneficiary, versus a decrease of $1.41 (95% CI: $0.73, $2.09) for a decrease in primary care physician availability. However, changes in the national workforce size of primary care physicians were associated with the largest changes in national spine spending.

Provider availability affects individual spine spending, with substantial changes observed at the national level. The effect depends on provider type and whether availability increases or decreases. Policymakers should consider how changes in the size of the physician workforce affect healthcare spending.