Assessment of sickness certification and concepts of musculoskeletal disease and illness in the general population

OBJECTIVE: To investigate how laymen assess the need for sickness certification and how they use the concepts "disease" and "illness" in relation to musculoskeletal disorders. DESIGN: Mail questionnaire with simulated case histories. SUBJECTS: A stratified, random sample of 600 Norwegians, aged 16-69 years. MAIN OUTCOME MEASURES: Scores that measured the respondents' use of the concept "illness", and their view on need for sickness certification were constructed and analysed. RESULTS: Response rate was 54%. The respondents perceived seven case histories describing musculoskeletal health problems more often as "illness" (61%) than as "disease" (46%). There was a close correlation between the use of "illness" and assessed need for sickness certification. However, sickness certification could be suggested for cases with neck pain, even if the patient was not perceived as ill. Women suggested sickness certification significantly more often than men. Age, length of education, and personal experience with serious musculoskeletal health problems influenced suggestions on certification among men. However, these variables could not explain any difference in use of the concept "illness".