Implications for practice Self-report measures of a work-related illness are used to estimate the prevalence of a work-related disease and the differences in prevalence between populations, such as different occupational groups representing

different exposures. From this review, we know that prevalence estimated with symptom questionnaires was mainly higher than prevalence estimated with the reference standards, except for hand eczema and respiratory disorders. If prevalence MAPK Inhibitor Library was estimated with self-diagnosis questionnaires, questionnaires that use a combined score of health symptoms, or for instance use pictures to identify skin diseases, they tended to agree more with the prevalence based on the reference standard. The choice for a certain type of questionnaire depends also on the expected prevalence of the health condition in the target population. If the expected prevalence in the target population is high enough (e.g., over 20%), a self-report measure with high specificity (>0.90) and acceptable sensitivity (0.70–0.90) may be the best choice. It will reflect the “true” prevalence because it will find many true cases with a limited number Sirolimus of false negatives. But if the expected prevalence is low (e.g., under 2%), the same self-report measure will overestimate the “true” prevalence considerably; it will successfully identify

most of the non-cases but at the expense of a large number of false positives. This holds equally true if self-report is used for case finding in a workers’ health surveillance program. Therefore, when choosing a self-report questionnaire for this purpose, one should also take into account other aspects of the

target condition, including the severity of the condition and treatment possibilities. If in workers’ health surveillance it is important to find as many cases as possible, the use a sensitive symptom-based self-report questionnaire (e.g., the NMQ for musculoskeletal disorders or a symptom-based questionnaire for skin problems) is recommended, under the condition of a follow-up including a medical examination Cepharanthine or a clinical test able to filter out the large number of false positives (stepwise diagnostic procedure). Although the agreement between self-assessed work relatedness and expert assessed work relatedness was rather low on an individual basis, workers and physicians seemed to agree better on work relatedness compared with the non-work relatedness of a health condition. Adding well-developed questions to a specific medical diagnosis exploring the relationship between symptoms and work may be a good strategy. Implications for research In the validation of patients’ and workers’ self-report of symptoms, signs, or illness, it is necessary to find out more about the way sources of heterogeneity like health condition, type of self-report, and type of reference standard influence the diagnostic accuracy of self-report.