Analyses
REGRESSION, REGRESSIONS
To reduce the risk of biasThe R package Costs and outcomes were analysed simultaneously with bivariate regression models, allowing for correlations between costs and outcomes to be incorporated (in contrast to separate regressions). Such regressions are generally robust to skewed data.The estimated coefficient of arm in these regressions allowed the incremental cost-effectiveness ratio (ICER) to be estimatedUncertainties in the mean incremental costs and mean incremental effect (for each outcome), which determines estimated levels of cost-effectiveness, were explored using bootstrapIn the base case (primary) economic analysis, the QALYs and costs up to T2—in line with the primary clinical-effectiveness outcome in CCA—repeats the base case, but only including participants for whom we have complete data; investigates the impact of MIPer-protocol analysis—investigates how results differ if we only consider those attending at least 50% (four out of eight) of the mindfulness sessions.Conduct evaluation at 12 months—extend the base case analysis to include costs and benefits up to T3, investigating whether benefits continue beyond the examination term.Conduct a cost-effectiveness analysis (CEA) for CORE-OM—as for the base case, but measure benefits in terms of CORE-OM at T2 (eg, calculate the cost per CORE-OM point).Conduct a CEA for WEMWBS—as for the base case, but measure benefits in terms of WEMWBS at T2 (eg, calculate the cost per WEMWBS point).All analyses were conducted in 