title: Sensitivity and specificity of self-reported acne in 18-year-old adolescent males.
abstract: BACKGROUND
  Self-reporting is widely used in medical research. The objective of the present study was to evaluate the specificity and sensitivity of self-reported lesions of acne (scars and active lesions) obtained by an interview with the examination carried out by a dermatologist.
  
  
  METHODS
  A questionnaire was applied to male adolescents who registered for obligatory military service. After that, skin examination was carried out.
  
  
  RESULTS
  Of the 2,191 adolescents examined, 474 (21.60%) showed acne scars, and 625 (28.51%) admitted to having scars. The sensitivity of self-reported scars was 50.84%, and the specificity was 77.65%. The prevalence of active acne obtained by the dermatological examination was 85.76% and from self-reported acne was 76.12%, with a sensitivity of 80.95% and a specificity of 52.88%. Neither schooling nor social class made any difference to sensitivity or specificity.
  
  
  CONCLUSIONS
  Our findings showed that sensitivity and specificity of self-reported acne was very low, pointing out that, in a sample of adolescents, self-reporting of acne shows itself as an inadequate instrument for epidemiological studies.
authors.affiliation: Department of Dermatology, Catholic University of Pelotas, Pelotas, Brazil Department of Dermatology, Federal University of Pelotas, Pelotas, RS, Brazil. hiramalmeidajr@hotmail.com
authors.forename: Hiram de
authors.initials: Hd
authors.lastname: Almeida
authors.forename: Josayres
authors.initials: J
authors.lastname: Cecconi
authors.forename: Rodrigo P
authors.initials: RP
authors.lastname: Duquia
authors.forename: Paulo R
authors.initials: PR
authors.lastname: Souza
authors.forename: Juliano
authors.initials: J
authors.lastname: Breunig
mesh_terms: D000152:Acne Vulgaris / Q000175:diagnosis* / Q000453:epidemiology*; D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D006801:Humans; D008297:Male; D008889:Military Personnel / Q000706:statistics & numerical data*; D015995:Prevalence; D057566:Self Report; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires