CG123 Common mental health disorders - National Institute for ...

Methods used to develop this guidelineFigure 2: Receiver operator characteristic curveNegative and positive likelihood ratiosNegative and positive likelihood ratios (LR–/LR) are considered not to bedependent on prevalence. LR– is calculated by sensitivity/1-specificity and LR is1-sensitivity/specificity. A value of LR 5 and LR– 0.3 suggests the test is relativelyaccurate (Fischer et al., 2003).Diagnostic odds ratioThe diagnostic OR is LR/LR–; a value of 20 or greater suggests a good level ofaccuracy (Fischer et al., 2003).Publication biasWhere there was sufficient data, the intention was to use funnel plots to explore thepossibility of publication bias. Asymmetry of the plot would be taken to indicatepossible publication bias and investigated further. However, due to a paucity of data,funnel plots could not be used.3.6 HEALTH ECONOMIC METHODSThe aim of the health economics was to contribute to the guideline’s development byproviding evidence on the cost effectiveness of interventions for common mentalhealth disorders covered in the guideline. This was achieved by:● systematic literature review of existing economic evidence● decision-analytic economic modelling.Systematic reviews of economic literature were conducted in all areas covered inthe guideline. Economic modelling was undertaken in areas with likely major resource51