[Rewards in questionnaire studies].
D000368:Aged; D001416:Back Pain / Q000453:epidemiology; D004812:Epidemiologic Methods; D005260:Female; D005264:Femoral Fractures / Q000453:epidemiology; D006620:Hip Fractures / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway; D010358:Patient Participation; D011795:Surveys and Questionnaires
Spørreskjemaundersøkelser og belønning.