Economic evaluation alongside a randomised controlled crossover trial of modified group cognitive behavioural therapy for anxiety compared to treatment-as-usual in adults with Asperger Syndrome

摘要

There is a growing interest in using group cognitive behavioural therapy (CBT) with people who have Asperger Syndrome (AS) and comorbid mental health problems. This study aims to assess the cost-effectiveness of modified group CBT for adults with AS experiencing co-occurring anxiety compared to treatment-as-usual. Economic evaluation alongside a pilot, multi-centre, single-blind, randomised controlled crossover trial. Costs from the UK public sector (National Health Service and Social Services) and societal perspectives, quality-adjusted life-years (QALYs), incremental net (monetary) benefit (INB), expected value of perfect information, expected value of sample information, expected net gain of sampling, and efficient sample size of a future trial are reported. Over 48 weeks, from the societal perspective, CBT results in additional costs of £6647, with only a 0.015 incremental gain in QALYs, leading to a negative INB estimate of £6206 and a 23% probability of cost-effectiveness at a threshold of £30,000/QALY. Results from sensitivity analyses support the unlikely cost-effectiveness of CBT, but indicate the potential for cost-effectiveness over longer time horizons. Eliminating decision uncertainty is valued at £277 million and the efficient sample size for a future trial is estimated at 1,200 participants per arm. Relatively small sample size and prevalence of missing data present challenges to the interpretation of the results. Current evidence from this small pilot study suggests that on average, modified group CBT is not cost-effective. However, there is much decision uncertainty so such a conclusion could be wrong. A large, full scale trial to reduce uncertainty would be an efficient investment for the UK health economy.