Objectives: To assess the cost-effectiveness of providing practical training to general practitioners (GPs) in shoulder problems, and administering a local anaesthetic (lignocaine) vs steroidal (cortisone) injection.
Methods: A cost-effectiveness analysis conducted alongside a cluster randomized trial with a factorial design, in general practices across five centres within the UK. A total of 155 participant GPs were randomized to receive training or no training with 200 participants randomized to either lignocaine or cortisone. Health care costs, quality-adjusted life years (QALYs) and incremental cost per QALY gained over 1 year estimated from a health system and a societal perspective were the main outcomes measured.
Results: Over 1 year, training GPs costs on average an additional pound sterling 211 (95% credibility interval - pound sterling 237, pound sterling 661) than no training and produces higher mean QALYs (0.075; -0.004, 0.154) per patient, yielding an incremental cost-effectiveness ratio of pound sterling 2813 per QALY gained for trained GPs. Over the same period of 1 year, lignocaine costs an average of pound sterling 122 more (- pound sterling 232, pound sterling 476) than cortisone and produces virtually no differential gain in mean QALYs (0.001; -0.068, 0.070), yielding an incremental cost per QALY gained of pound sterling 122,000 for lignocaine compared with cortisone. Across a range of cost-effectiveness thresholds, cortisone is as cost effective to inject as lignocaine. The probability that training is cost effective is above 0.95 at thresholds above pound sterling 20,000.
Conclusions: Providing practical training to GPs about shoulder problems is cost effective and there is little uncertainty regarding this decision. The choice between lignocaine and cortisone is more uncertain and it is likely that there is significant value of further research to reduce this uncertainty.
Trial registration: The International Standard Randomised Controlled Trial Number is 58 537 244.