title: Derivation and validation of a risk-factor model for detection of oral potentially malignant disorders in populations with high prevalence.
abstract: BACKGROUND
  Oral and pharyngeal cancers constitute the sixth most common type of cancer globally, with high morbidity and mortality. In many countries, most cases of oral cancer arise from long-standing, pre-existing lesions, yet advanced malignancies prevail. A new approach to early detection is needed. We aimed to validate a model for screening so that only high-risk individuals receive the clinical examination.
  
  
  METHODS
  A community-based case-control study (n=1029) in rural Sri Lanka assessed risk factors and markers for oral potentially malignant disorders (OPMD) by administering a questionnaire followed by an oral examination. We then developed a model based on age, socioeconomic status and habits of betel-quid chewing, alcohol drinking and tobacco smoking, with weightings based on odds ratios from the multiple logistic regression. A total, single score was calculated per individual. Standard receiver-operator characteristic curves were plotted for the total score and presence of OPMD. The model was validated on a new sample of 410 subjects in a different community.
  
  
  RESULTS
  A score of 12.0 produced optimal sensitivity (95.5%), specificity (75.9%), false-positive rate (24.0%), false-negative rate (4.5%), positive predictive value (35.9%) and negative predictive value (99.2%).
  
  
  CONCLUSIONS
  This model is suitable for detection of OPMD and oral cancer in high-risk communities, for example, in Asia, the Pacific and the global diaspora therefrom. A combined risk-factor score of 12.0 was optimal for participation in oral cancer/OPMD screening in Sri Lanka. The model, or local adaptations, should have wide applicability.
authors.affiliation: Dental Institute, Maharagama, Colombo 10280, Sri Lanka. hemanthaamarasinghe@yahoo.com
authors.forename: H K
authors.initials: HK
authors.lastname: Amarasinghe
authors.forename: N W
authors.initials: NW
authors.lastname: Johnson
authors.forename: R
authors.initials: R
authors.lastname: Lalloo
authors.forename: M
authors.initials: M
authors.lastname: Kumaraarachchi
authors.forename: S
authors.initials: S
authors.lastname: Warnakulasuriya
mesh_terms: D000328:Adult; D000428:Alcohol Drinking / Q000009:adverse effects; D001114:Areca / Q000009:adverse effects; D006801:Humans; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000453:epidemiology* / Q000517:prevention & control; D016017:Odds Ratio; D010610:Pharyngeal Neoplasms / Q000453:epidemiology* / Q000517:prevention & control; D015995:Prevalence; D012372:ROC Curve; D018570:Risk Assessment; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D012959:Socioeconomic Factors; D013188:Sri Lanka / Q000453:epidemiology; D011795:Surveys and Questionnaires