Modelled cost-effectiveness analysis of the Support and Treatment After Replacement (STAR) care pathway for chronic pain after total knee replacement compared with usual care

Background

The aim of the study was to estimate the long-term cost-effectiveness of the Support and Treatment After Replacement (STAR) care pathway for chronic pain after total knee replacement compared with usual postoperative care.

Methods

Study design: A decision-analytic (cohort Markov) model was used for the simulation with time dependent annual transition probabilities and a time horizon of five years.

Setting: Patients treated by National Health Service (NHS) hospitals in England and Wales.

Study population: Adults classified as having chronic pain three months after undergoing a total knee replacement.

Intervention: The STAR care pathway following a total knee replacement.

Comparator: Usual postoperative care following a total knee replacement.

Perspective: The study was undertaken from the perspective of the NHS.

Outcome measures: Quality-adjusted life years and healthcare costs.

Discounting: A rate of 3.5% for both costs and health utility.

Results

Model results indicate that the STAR intervention would dominate current practice by providing a gain in quality-adjusted life years (QALYs) of 0.086 and a reduction of £375 (per person) in costs over the first five years. The incremental net monetary benefit of the STAR intervention was estimated at £2,086 (at a threshold of £20,000 per QALY). Probabilistic sensitivity analysis suggests the STAR intervention is likely to be cost-effective with a probability of 0.62.

The results remain robust to changes in model assumptions on comparator utility and the timing of the start of the intervention. If hospital admission costs are assumed not to be reduced by the STAR intervention, it would no longer be cost saving, but it would likely be cost-effective based on probabilistic sensitivity analysis (0.59).

Conclusion

Evidence from the economic model suggests that the STAR care pathway is likely to be cost-effective and potentially dominant from an NHS perspective.

Trial registration

The STAR trial is registered with ISRCTN, ISRCTN92545361.