Analytical approach:
The effectiveness and resource use evidence was from a clinical trial. The time horizon was one year. The authors reported that the perspective was that of the UK NHS.
Effectiveness data:
The clinical and effectiveness evidence was from a clinical trial (Foster, et al. 2007, see 'Other Publications of Related Interest' below for bibliographic details). Patients were recruited to the trial between November 2003 and October 2005, and followed-up for one year. There were 1,061 eligible patients, and 352 were randomly allocated to the groups; advice and exercise (n=116), advice, exercise, and acupuncture (n=117), and advice, exercise, and non-penetrative acupuncture (n=119). The primary clinical outcome was the change from baseline to six months, in the score on the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index. Multiple imputation was used for incomplete data.
Monetary benefit and utility valuations:
The utility estimates were derived using the European Quality of life (EQ-5D) questionnaire, administered at baseline, six weeks, six months, and one year. These responses were converted into utility values, using estimates from a large sample of the UK population.
Measure of benefit:
The measure of benefit was quality-adjusted life-years (QALYs) gained. These were calculated for the year, using area-under-the-curve analysis, adjusting for baseline utility, using multiple regression.
Cost data:
The direct costs to the NHS included those of consultations with primary care practitioners, hospital consultant visits, treatment sessions, contacts with other health care providers, and prescription medications. The number and content of treatment sessions were from standard forms completed by the therapists. All other health care resource use was collected from patient-completed postal questionnaires, which included over-the-counter medication use. Multiple imputation was used for incomplete data. The unit costs were from a compendium of UK health care costs, NHS reference costs, and the British National Formulary. The price year was 2004 to 2005 and the costs were in UK pounds sterling (£).
Analysis of uncertainty:
The uncertainty was assessed, using 5,000 bootstrapped replications of the mean QALY and cost differences, with the data pairs plotted on the cost-utility plane. The results were presented in a cost-effectiveness acceptability curve. Several other sensitivity analyses were performed, including the exploration of the impact of missing data by conducting a complete-case analysis, and the inclusion of non-NHS health care resources.