Rehabilitation in resurfacing hip arthroplasty patients: cost-effectiveness results from a randomised clinical trial

Background: In young active adults hip resurfacing arthroplasty (RHA) has been shown to provide good outcomes. A randomised controlled trial recently showed a programme of accelerated physiotherapy (AP) to be effective in terms of improving functional outcomes and range of motion when compared with standard physiotherapy (Barker et al., 2013). Purpose: This study reports trial-based cost-effectiveness estimates of AP compared with standard physiotherapy following RHA. Methods: 80 male patients undergoing RHA were randomised either to standard physiotherapy (n= 40) or to AP (n= 40). The AP program was without hip precautions and patients were fully weight bearing. AP exercises included on-going gait re-education, direction, activities to increase the range of hip movement and lower limb strength, and balance training and weight bearing exercises. AP patients also received an additional rehabilitation session two weeks after surgery. Patients in the standard arm received conventional physiotherapy with hip precautions and standard post operative hip exercises. Costs: An NHS and patients’ perspective was used when costing. Patients recorded NHS and private health care contacts at 6, 16, and 52 weeks post randomisation. Patients in the AP arm were assigned the cost of an additional rehabilitation visit. Resource use data were costed used using 2012/13 unit costs in UK £ Sterling. Outcome: The 3-level EuroQoL EQ-5D questionnaire was used to measure Health Related Quality of Life (HRQoL) with responses converted into utilities using the UK social tariff. Utilities were combined with survival data to calculate Quality Adjusted Life Years (QALYs) for each patient. Statistics: Multiple imputation (MI) was used to handle missing data. Results within arms are reported using means and standard errors (SE). Differences between arms are described using mean differences and 95% confidence intervals. Uncertainty around cost-effectiveness results was examined using 2000 non-parametric bootstraps. Results: The mean (SE) overall QALY in the accelerated group was 0.84 (0.02) and in the standard group was 0.71 (0.03) (mean QALY difference 0.13 in favour of AP (95% CI 0.05 to 0.21, p< 0.01). Mean HRQoL over time was lower on average in the standard physiotherapy arm. The overall mean cost difference (including the extra physiotherapy visit for Accelerated patients at £34)was−£170.43 (95% CI −£550.69 to £209.84. The mean (SE) cost per patient of NHS health care contacts reported by patients to 52 weeks was £410.99 (£91.14) in the AP arm and £615.41 (£150.70) in the standard arm (mean cost difference −£204.43, 95% CI −£584.69 to £175.84). AP patients had more physiotherapy home visits but fewer (albeit not significantly) visits to surgeons, hospital doctors, physiotherapists, and hospital inpatients days. Conclusion(s): The preliminary results of the study showed an encouraging economic profile for the AP programme for RHA patients when compared with standard physiotherapy. Adopting a £20,000 per QALY threshold, the AP programme is highly cost-effective; even lowering the threshold to £0 per QALY the AP still has a high probability of being cost-effective (0.88). Implications: The findings demonstrate that a new protocol that may increase delivery costs can still be cost-effective when other healthcare costs and cost effectiveness is evaluated.