title: Measuring risk perceptions of skin cancer: reliability and validity of different operationalizations.
abstract: OBJECTIVE
  Risk perceptions play a pivotal role in health behaviour theories. Accurate measurement is essential in order to investigate the explanatory value and effectiveness of interventions influencing these beliefs. This study investigated the reliability and predictive validity of different risk perception operationalizations related to skin cancer and sunscreen use in order to explain the inconsistent findings in literature regarding the relationship between risk perceptions and (cancer related) behaviours.
  
  
  METHODS
  Two on-line surveys were conducted. Study 1 (N= 175) was conducted among university students to investigate the test-retest reliability of different operationalizations of perceived likelihood and perceived severity and to assess their correlations with sunscreen use. Study 2 (N= 418) was a prospective study among Dutch adults and assessed longitudinal correlations between the different operationalizations and sunscreen use.
  
  
  RESULTS
  Internal consistency (alpha) ranged between .13 and .90 for likelihood measures and between .37 and .88 for severity measures. Test-retest correlations (r/ICC) ranged between .51 and .82 for the likelihood measures and between .58 and .75 for the severity measures. Conditional likelihood estimates, particularly when phrased affectively (feeling at risk), and comparative severity questions were the strongest correlates of behaviour.
  
  
  CONCLUSIONS
  Conditional likelihood and comparative severity might be better predictors of health behaviour than commonly used operationalizations of risk perception. These measures may be relevant for use in the development and evaluation of intervention programmes, and should be acknowledged by health behaviour theories. Suggestions for future research are discussed.
authors.affiliation: School for Public Health and Primary Care (Caphri), Department of Health Promotion, Faculty of Health, Medicine and Life Sciences, Maastricht University, The Netherlands. eva.janssen@maastrichtuniversity.nl
authors.forename: Eva
authors.initials: E
authors.lastname: Janssen
authors.forename: Liesbeth
authors.initials: L
authors.lastname: van Osch
authors.forename: Hein
authors.initials: H
authors.lastname: de Vries
authors.forename: Lilian
authors.initials: L
authors.lastname: Lechner
mesh_terms: D000328:Adult; D005260:Female; D015438:Health Behavior; D007722:Health Knowledge, Attitudes, Practice; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009426:Netherlands; D011446:Prospective Studies; D015203:Reproducibility of Results; D012307:Risk Factors; D040242:Risk Reduction Behavior; D012878:Skin Neoplasms / Q000517:prevention & control* / Q000523:psychology*; D013472:Sunlight / Q000009:adverse effects; D013473:Sunscreening Agents / Q000627:therapeutic use*; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D013473:Sunscreening Agents