Review on the validity of self-report to assess work-related diseases

Abstract

Purpose: Self-report is an efficient and accepted means of assessing population characteristics, risk factors, and diseases. Little is known on the validity of self-reported work-related illness as an indicator of the presence of a work-related disease. This study reviews the evidence on (1) the validity of workers' self-reported illness and (2) on the validity of workers' self-assessed work relatedness of an illness.

Methods: A systematic literature search was conducted in four databases (Medline, Embase, PsycINFO and OSH-Update). Two reviewers independently performed the article selection and data extraction. The methodological quality of the studies was evaluated, levels of agreement and predictive values were rated against predefined criteria, and sources of heterogeneity were explored.

Results: In 32 studies, workers' self-reports of health conditions were compared with the "reference standard" of expert opinion. We found that agreement was mainly low to moderate. Self-assessed work relatedness of a health condition was examined in only four studies, showing low-to-moderate agreement with expert assessment. The health condition, type of questionnaire, and the case definitions for both self-report and reference standards influence the results of validation studies.

Conclusions: Workers' self-reported illness may provide valuable information on the presence of disease, although the generalizability of the findings is limited primarily to musculoskeletal and skin disorders. For case finding in a population at risk, e.g., an active workers' health surveillance program, a sensitive symptom questionnaire with a follow-up by a medical examination may be the best choice. Evidence on the validity of self-assessed work relatedness of a health condition is scarce. Adding well-developed questions to a specific medical diagnosis exploring the relationship between symptoms and work may be a good strategy.

Fig. 1

Search results as the number of scientific articles retrieved in the different stages of the search and selection procedure

Fig. 2

Methodological quality graph: Review authors’ judgements about each methodological quality item presented as percentages across all included studies

Fig. 3

Forest plot of 19 included studies, categorized by type of self-report measure. TP true positive, FP false positive, FN false negative, TN true negative. Between the brackets the 95% confidence intervals (CI) of sensitivity and specificity. The figure shows the estimated sensitivity and specificity of the study (black square) and its 95% CI (black horizontal line)

Fig. 4

Summary ROCs to explore heterogeneity based on overall study quality, type of health condition, and type of self-report measure