Background/Purpose: The American College of Rheumatology (ACR) strongly recommends exercise therapy as a first-line conservative treatment for individuals with knee osteoarthritis (OA).¹ Evidence supporting manual therapy for knee OA has shown varying levels of effectiveness.¹ In this population, there is minimal research regarding the use of “booster” physical therapy (PT) sessions– visits spaced across a longer period of time to supplement initial treatments.²The purpose of this study was to compare the cost-effectiveness of combinations of exercise therapy and manual therapy with or without booster sessions in individuals with knee OA.

Methods: Data were collected as part of a 2-year multi-site study of 300 individuals who met ACR criteria for knee OA. A Markov model was constructed to compare 4 PT treatment strategies: (1) 12 visits of exercise therapy alone (EX); (2) 9 visits of exercise therapy plus 3 booster sessions spaced across a 12-month period (EX+B); (3) 12 visits of exercise therapy plus manual therapy (EX+MT); (4) 9 visits of exercise therapy plus manual therapy and 3 booster sessions (EX+MT+B). Total health care costs were estimated from the societal perspective using patient reported outcome measures as well as data from the Healthcare Utilization Project and the Medicare physician fee schedule. Utilities were measured using the U.S. version of the Euroqol-5-Dimension tool. Incremental cost-effectiveness ratios (ICERs) are expressed in Quality-Adjusted Life Years (QALYs).

Results: In the 2-year base case analysis, the booster strategies (EX+MT+B and EX+B) dominated (lower health care costs and greater effectiveness) the no-booster strategies (EX+MT and EX). EX+MT+B had the lowest total health care costs. The EX+B group cost $1,061 more and gained 0.082 more QALYs compared with EX+MT+B, for $12,900/QALY gained. In 1-way sensitivity analyses of all parameters, EX+B continued to be cost-effective (<$100,000/QALY gained) compared with EX+MT+B, unless the likelihood of staying in good or poor function was varied to a degree that would be highly improbable given what was observed in this study. In a preliminary model projecting costs and utilities over a 5-year period, the EX+B strategy remained well within the range that most would consider to be cost-effective by third-party payers.  

Conclusion: Spacing exercise-based PT sessions over 12 months using periodic “booster” sessions was less costly and more effective over 2 years than strategies not containing “booster” sessions. Among booster strategies, the group receiving manual therapy in addition to exercise therapy (EX + MT + B) had lower costs but lower gains in QALYs than the EX + B group.

1. Hochberg MC, Altman RD, April KT, et al. American College of Rheumatology 2012 recommendations for the use of nonpharmacologic and pharmacologic therapies in osteoarthritis of the hand, hip, and knee. Arthritis Care Res 2012;64(2):465-74.
2. Bennell KL, Kyriakides M, Hodges PW, Hinman RS. Effects of two physiotherapy booster sessions on outcomes with home exercise in people with knee osteoarthritis: a randomized controlled trial. Arthritis Care Res 2014;66(11):1680-7.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/what-is-the-most-cost-effective-physical-therapy-strategy-to-treat-knee-osteoarthritis/