(487) Knee and hip replacements: prevalence and healthcare utilization and costs pre- and post-surgery for Medicare Advantage members

Abstract

During the last decade, knee and hip replacement rates in the US rose dramatically. While joint replacement may result in improvement in pain and functionality, the rise in prevalence and associated high cost call for better selecting appropriate candidates to ensure successful outcomes. This study examined the prevalence of knee and hip replacements in Humana’s Medicare Advantage population, 2007–2012. Knee and hip replacement cohorts were also followed longitudinally to determine changes in osteoarthritis (OA)–related healthcare utilization and costs from 180 days pre-surgery until 360 days post-surgery, relative to members with OA and steroid or viscosupplementation injection(s) into the knee or hip. The rate of knee replacements rose from 6.0 to 6.6 and the rate of hip replacements rose from 4.6 to 4.8 per 1,000 members enrolled during 2007-2012. Demographic characteristics were age: 70.7 years for knee, 71.7 years for hip, and 71.1 years for comparison cohort (P<.0001); RxRisk-V comorbidity score: 4.7 knee, 4.4 hip, 4.8 comparison cohort (P<.0001). Mean pre-index healthcare costs were $610 knee, $523 hip, and $717 comparison cohort (P<.0001). A difference-in-difference (DID) analysis comparing 180 days pre-index to days 181-360 post-index indicated that the decrease in OA-related costs post-surgery was greater in members with joint replacements than the comparison cohort (coefficient for knee replacement*time: -0.165; hip replacement*time: -0.438; P<.001 for both). A subgroup of knee replacement members diagnosed with depression had higher healthcare costs (coefficient: 0.167, P=0.05), implying need to address comorbid conditions and relationship to joint pain. Rates of venous thromboembolic events were greater post-surgery than pre-surgery, and only 55.9% of knee replacement and 56.6% of hip replacement cohorts received anti-coagulants post-surgery. While the overall DID results implied better outcomes among members with joint replacements, their high surgical costs may warrant the provider and patient explore all options prior to undergoing surgery. This study was sponsored by Humana Inc. and Pfizer Inc. During the last decade, knee and hip replacement rates in the US rose dramatically. While joint replacement may result in improvement in pain and functionality, the rise in prevalence and associated high cost call for better selecting appropriate candidates to ensure successful outcomes. This study examined the prevalence of knee and hip replacements in Humana’s Medicare Advantage population, 2007–2012. Knee and hip replacement cohorts were also followed longitudinally to determine changes in osteoarthritis (OA)–related healthcare utilization and costs from 180 days pre-surgery until 360 days post-surgery, relative to members with OA and steroid or viscosupplementation injection(s) into the knee or hip. The rate of knee replacements rose from 6.0 to 6.6 and the rate of hip replacements rose from 4.6 to 4.8 per 1,000 members enrolled during 2007-2012. Demographic characteristics were age: 70.7 years for knee, 71.7 years for hip, and 71.1 years for comparison cohort (P<.0001); RxRisk-V comorbidity score: 4.7 knee, 4.4 hip, 4.8 comparison cohort (P<.0001). Mean pre-index healthcare costs were $610 knee, $523 hip, and $717 comparison cohort (P<.0001). A difference-in-difference (DID) analysis comparing 180 days pre-index to days 181-360 post-index indicated that the decrease in OA-related costs post-surgery was greater in members with joint replacements than the comparison cohort (coefficient for knee replacement*time: -0.165; hip replacement*time: -0.438; P<.001 for both). A subgroup of knee replacement members diagnosed with depression had higher healthcare costs (coefficient: 0.167, P=0.05), implying need to address comorbid conditions and relationship to joint pain. Rates of venous thromboembolic events were greater post-surgery than pre-surgery, and only 55.9% of knee replacement and 56.6% of hip replacement cohorts received anti-coagulants post-surgery. While the overall DID results implied better outcomes among members with joint replacements, their high surgical costs may warrant the provider and patient explore all options prior to undergoing surgery. This study was sponsored by Humana Inc. and Pfizer Inc.