Does the type of medical insurance influence outcome after hip or knee total joint replacement?

Abstract

Introduction: The purpose of this study was to determine if Medicaid, Medicare and private patients undergoing primary total knee and hip arthroplasty reported different outcome scores.

Methods: From 2014-2016, 1076 patients that underwent a total hip arthroplasty and 1936 patients that underwent a total knee arthroplasty and completed a series KOOS/HOOS patient reported outcomes surveys. Available demographic information included gender, age, BMI and payer status. Baseline (pre-surgery) , 3-month and 1-year post-surgery survey responses were collected utilizing a web-based data collection system and reporting platform. Parametric and non-parametric methods of comparing central tendency measures for the captured responses between the insurance types (Medicare, Medicaid, BCBS, Private) were utilized to determine if significant differences exist. The difference between the baseline (pre-op) of the HOOS and KOOS score was calculated as delta, the difference between baseline and 3 months, baseline and 12 months and 3 months to 12 months. Results: The average overall KOOS and HOOS score at base line (pre-op) was 42.8 (KOOS) and 36.9 (HOOS). The average score at 3 months for KOOS and HOOS was 73.8 and 81.7 respectively. At one year the average score for the KOOS and HOOS was 81.2 and 86.5 respectively. The delta changes for the HOOS score in patients with Medicare at baseline to 3 months, baseline to 12 months and 3 months to 12 months were 45.1, 49.3 and 4.45 respectively. The delta changes for the HOOS score in patients with Medicaid at baseline to 3 months, baseline to 12 months and 3 months to 12 months were 47.7, 42.6 and -0.25 respectively. The delta changes for the HOOS score in patients with BCBS/Manage at baseline to 3 months, baseline to 12 months and 3 months to 12 months were 44.1, 49 and 4.88 respectively. The delta changes for the HOOS score in patients labeled as other/private at baseline to 3 months, baseline to 12 months and 3 months to 12 months were 44.4, 49.7 and 4.81 respectively. The delta changes for the KOOS score in patients with Medicare at baseline to 3 months, baseline to 12 months and 3 months to 12 months were 30.7, 36.7 and 6.03 respectively. The delta changes for the KOOS score in patients with Medicaid at baseline to 3 months, baseline to 12 months and 3 months to 12 months were 26.4, 32.6 and 9.25 respectively. The delta changes for the KOOS score in patients with BCBS/Manage at baseline to 3 months, baseline to 12 months and 3 months to 12 months were 32, 39.4 and 7.79 respectively. The delta changes for the KOOS score in patients with other/private at baseline to 3 months, baseline to 12 months and 3 months to 12 months were 31.3, 39.3 and 7.19 respectively.

Conclusion: Overall, the best reported outcome for the HOOS and HOOS was at 1 year, with minimal improvement between the 3 months follow up and 12 month follow up. At one year, there was no significant difference in KOOS/HOOS score for all three payer types. Medicaid and private insurance patients were significantly younger than Medicare patients (p<0.001). There was no significant difference in gender or BMI characteristics. Medicaid payer status was associated with lower improvement in KOOS and HOOS scores at one year post total knee arthroplasty or hip arthroplasty, compared to patients having Medicare or private health insurance. The difference at 3 month or, 3 to 12 months post-surgery was minimal. The data supports performing total knee replacements or hip arthroplasty in the Medicaid population. Additional investigation may shed light on why Medicaid patients demonstrate a slower recovery on patient reported outcome surveys.