4). Fig. 4 Summary ROCs to explore heterogeneity based on overall study quality, type of health condition, and type of self-report measure In the sROC plot on the type of health condition, a comparison is made between the results of 8 symptom questionnaires on Alvocidib musculoskeletal disorders (MSD), 8 on skin disorders, and 2 on hearing loss. Although the outcomes were highly variable, the combined sensitivity and specificity of symptom questionnaires

on skin disorders was slightly better than for symptom questionnaires on musculoskeletal PCI-32765 molecular weight disorders and hearing loss. However, there were only a few self-report measures with a optimal balance between sensitivity and specificity. In the sROC plot on type of self-report measure, a comparison is made between the results for 15 symptom questionnaires (i.e., questionnaires reporting symptoms of illness such as aches, pain, cough, dyspnoea, or itch), eight self-diagnostic questionnaires, (i.e., usually a single question asking whether the respondent suffered from a specified illness or symptom in a certain time frame), and two measures rating the severity of a health problem (i.e., how do you rate your hearing loss on a scale from 1 to 5). Although again the outcomes were highly variable, the combined sensitivity and specificity click here of symptom-based questionnaires was slightly better than for self-diagnosis or

than for severity rating. In addition, symptom-based questionnaires tended to have better sensitivity, whereas self-diagnosis questionnaires tended to have better specificity. Another source of heterogeneity may come from the variety in case definitions used in the studies for both self-report and reference standard. In the large cohorts

of Descatha et al. (2007), the agreement differed substantially acetylcholine depending on the definition of a “positive” questionnaire result. If the definition was extensive (i.e., “at least one symptom in the past 12 months”), the agreement between the Nordic Musculoskeletal Questionnaire (NMQ) and clinical examination was low. With a more strict case definition (i.e., requiring the presence of symptoms at the time of the examination), the agreement with the outcomes of clinical examination was higher. Comparable results on the influence of case definition were reported by Perreault et al. (2008) and Vermeulen et al. (2000). Looking at the influence of heterogeneity in the reference standard, it showed that comparison of self-report with clinical examination seemed to result in mainly moderate agreement, whereas comparison of self-report with test results was low for exposure-related symptoms and tests (Lundström et al. 2008; Dasgupta et al. 2007) and moderate for hearing loss (Gomez et al. 2001) and self-rated pulmonary health change (Kauffmann et al. 1997).