Self-reported skin complaints: validation of a questionnaire for population surveys.
BACKGROUND
Estimation of skin diseases in the community is challenging because we do not easily have access to the nonhealthcare-seeking population. A potential tool is a questionnaire asking for self-reported skin complaints. Such an instrument has not yet been developed.


OBJECTIVE
To validate a simple instrument assessing skin morbidity in the general adult population, to predict clinical skin morbidity from self-reported skin complaints.


METHODS
A questionnaire was drawn up in Norwegian and validated against clinical signs in two samples of an urban population, 100 healthcare-seeking adults in a dermatological clinic, and 100 nonhealthcare-seeking adults. A total self-reported score was calculated and validated against severity of clinical signs (no sign, trivial, moderate or severe). The inter-rater agreement was assessed in a small study including 16 patients from a dermatological clinic.


RESULTS
The participation rate was 98%. The sensitivity was 61%, the specificity 69% and the positive predictive value 82% when the caseness criterion was any clinical sign of skin disease. The agreement was good between the two observers for clinical skin morbidity, with kappa = 0.67.


CONCLUSIONS
This questionnaire is a simple tool to evaluate skin morbidity in an adult population. The use of self-reported complaints to predict clinical morbidity may be of value in quantifying and exploring skin diseases at the population level. Further studies are needed to improve the instrument. It is our intention to demonstrate the potential usefulness of this questionnaire in a forthcoming population survey in Norway.
Dalgard
F
F
Institute of General Practice and Community Medicine, P.B. 1130 Blindern, 0318 Oslo, Norway. florence.dalgard@samfunnsmed.uio.no
Svensson
A
A
Holm
J Ø
JØ
Sundby
J
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006302:Health Services Research / Q000379:methods; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway; D010342:Patient Acceptance of Health Care; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012871:Skin Diseases / Q000175:diagnosis* / Q000453:epidemiology*; D011795:Surveys and Questionnaires