Budget Impact of Funding an Intensive Diet and Exercise Program for Overweight and Obese Patients With Knee Osteoarthritis

ObjectiveDiet and exercise (D+E) for knee osteoarthritis (OA) is effective and cost-effective. However, cost-effectiveness does not imply affordability; the impact of knee OA-specific D+E programs on insurer budgets is unknown. MethodsWe estimated changes in undiscounted medical expenditures (2016 US dollars) with and without a D+E program. We accounted for both additional program outlays and potential savings from reduced use of other knee OA treatments and from reduced incidence of comorbidities. We adopted the perspective of a representative commercial insurance plan covering 200000 individuals aged 25 to 64 years and a representative Medicare Advantage plan covering 200000 Medicare-eligible individuals aged 65 years and older. We used the Osteoarthritis Policy Model, a validated microsimulation model of knee OA, to model D+E efficacy (measured by pain and weight reduction), adherence, and price based on the Intensive Diet and Exercise for Arthritis (IDEA) trial. In sensitivity analyses, we varied time horizon, D+E efficacy, and D+E price. ResultsOver 3 years, the D+E program increased spending by $752200 ($0.10 per member per month [PMPM]) in the commercial plan and by $6.0 million ($0.84 PMPM) in the Medicare plan. Over 3 years, the D+E program reduced opioid use by 6% and 5% and reduced total knee replacements by 5% and 4% in the commercial and Medicare plans, respectively. Expenses were higher in the Medicare plan because it had more patients with knee OA than the commercial plan. ConclusionAlthough there is no established threshold to define affordability, a D+E program for knee OA would likely produce expenditures comparable with outlays for other health-promotion interventions.