The use of case histories to explore concepts of disease, illness and sickness certification.

A questionnaire with 12 case histories was constructed to investigate views on sickness certification and concepts of disease and illness among GPs and laymen. It was mailed to random samples of 436 Norwegian GPs and 600 Norwegians, stratified for gender, age and residence. Response rates were low, 44% for doctors, and 54% for laymen, probably indicating that the method was more suitable for smaller surveys. Case histories could be used to compare views of GPs and laymen on the concepts of disease and illness. They were also useful in examining views on sickness certification, but, in that case, they probably only reveal what respondents thought should be done. From this study it was not safe to conclude how often, and for what medical conditions doctors would issue sickness certificates in practice. ICPC was useful for coding diagnostic suggestions, set by GPs, but will be more useful after inclusion of criteria and more extensive synonym lists.