Abstract
Research Type:
Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies
Introduction/Purpose:
Insurance type, as a social determinant of health, impacts healthcare utilization and access. Understanding its effect on outcomes is essential for addressing health disparities. Socioeconomic status (SES) has been studied as a risk factor for complications following ankle fracture surgery. While prior literature has investigated the effect of SES on functional outcomes as measured by the validated Patient Reported Outcome Measurement Information System (PROMIS) after various orthopedic injuries, limited studies have analyzed whether SES impacts functional outcomes after ankle fracture surgery specifically. This study therefore assessed the relationship between insurance type and PROMIS physical function (PF) and pain interference (PI) after ankle fracture surgery. We hypothesized that there would be no significant differences in outcomes among anatomically reduced fractures when stratified by insurance type.
Methods:
This was a retrospective review of 782 patients who underwent ankle fracture surgery at a single institution between January 2016-December 2021. Two foot and ankle fellowship-trained orthopaedic surgeons independently reviewed all radiographs and assessed reduction quality at final follow-up. Patients with multiple extremity injuries at time of presentation, open fractures, and pilon variants were excluded. Final analysis included 182 patients at final follow-up with an anatomic reduction of the ankle who completed post-operative PROMIS PF and PI computerized adaptive tests. Insurance was categorized as “private,” “Medicaid,” “Medicare,” or “worker’s compensation.” The Kruskal-Wallis test assessed differences in PROMIS scores across insurance types and Dunn’s test with a Bonferroni correction identified significant pairwise comparisons. Linear regression was used to evaluate the effect of insurance on PROMIS scores. PI scores showed a right-skewed distribution, and thus were modeled with a gamma distribution and log-link. Models were adjusted for clinically relevant covariates.
Results:
12/182 patients (6.6%) had Medicaid, 21/182 (11.5%) had Medicare, 142/182 (78.0%) had private, and 7/182 (3.9%) received worker’s compensation. Medicaid had the lowest mean PF (47.36±9.57) and highest mean PI (55.53±8.15). When adjusting for multiple comparisons, no significant differences in PF by insurance existed (p=0.06), while differences in PI remained significant (p=0.01). Medicaid was significantly associated with lower PF scores compared to private insurance (p=0.03) when adjusting for age alone. This association was no longer significant after adjusting for fear of reinjury (p=0.25). Medicaid was associated with higher PI scores (p < 0.01). After adjusting for fear of reinjury, this association remained significant (p=0.02). Differences in the proportion of patients with fear of reinjury were statistically significant (p=0.04) with the highest proportion in Medicaid patients (50%).
Conclusion:
Anatomic fixation of ankle fractures results in patients achieving population mean PF regardless of insurance type. Patients with Medicaid demonstrated higher PI and higher proportions of fear of reinjury postoperatively, which may stem from a larger proportion of these patients with jobs requiring physical labor and continuous weight-bearing while experiencing an inability to modulate their lifestyle to promote optimal recovery due to financial necessity. To reduce such disparities, future investigations should address fear of reinjury and higher postoperative pain in this population.