Analytical approach:
The effectiveness and cost data were collected from a single clinical trial. The time horizon of the study was two years. The perspectives of the analysis were reported to have been those of the health care system (UK National Health Service) and society.
Effectiveness data:
The effectiveness data were collected from a multi-centre randomised controlled trial. The patients were recruited over a two-year period. The details of the patient selection and methods of randomisation were not reported in this study, but the authors referred readers to the original study (Dziedzic, et al. 2005, see 'Other Publications of Related Interest' below for bibliographic details). The patients were followed-up at six weeks and at six months. The three groups were reported to be comparable in terms of their baseline demographic and clinical characteristics. The sample consisted of 113 patients in the AE group, 115 in the MT group and 120 in the PSWD group. The primary outcomes were neck pain and disability evaluated using the Neck Pain Questionnaire (NPQ).
Monetary benefit and utility valuations:
The patients’ utility was valued using the self-administered European Quality of Life (EQ-5D) questionnaire at baseline, and six weeks and six-months post-randomisation.
Measure of benefit:
The measures of benefit were the point change in the NPQ and quality-adjusted life-years (QALYs).
Cost data:
The direct cost categories included physiotherapy and PSWD sessions (including the purchase and maintenance of equipment), prescription and over the counter medicines, and consultations with general practitioners, nurses, physiotherapists, and other professionals in the outpatient setting. The resource use was recorded by the treating physiotherapist on patient case reports. Non-attendance (did not attend and unable to attend) and attendance were also recorded. The costs for those unable to attend were excluded as it was assumed that these appointments could be reallocated. Additional treatment, specific to the patients' neck conditions, was reported on the self-administered questionnaires. Productivity costs, based on the patient-reported details of their work status, were calculated using the friction cost method. Most costs were obtained from official sources. All of them were reported for the price year 2003 to 2004 and were in UK pounds sterling (£).
Analysis of uncertainty:
The impact of missing data on the NPQ point changes, QALYs and costs was assessed by conducting multiple imputations using the data augmentation method and the relevant details were reported. Cost and effect pairs were bootstrapped and plotted using cost-effectiveness planes, to illustrate the level of uncertainty surrounding the estimates, and cost-effectiveness acceptability curves (CEACs), to show the probability of cost-effectiveness across willingness-to-pay (WTP) thresholds.