Validity of two methods for assessing oral health status of populations

Objective: This investigation assessed two methods for estimating epidemiologic indicators of oral health status among children: (1) a visual-only screening, performed independently by a dental hygienist and a registered nurse; and (2) a parent- or guardian-completed questionnaire. The indicators included dichotomous variables measuring dental caries and treatment needs, presence of sealants, injuries to the anterior teeth, and dental fluorosis. Methods: Following training and calibration, data were collected over an eight-day period in April 1994 among 632 elementary schoolchildren (aged 5 to 12 years) in Monticello, Georgia. Both screening and questionnaire findings were compared pairwise with results from visual-tactile examinations done by a dentist. Validity, represented by sensitivity, specificity, and predictive values, was assessed for screening results from the dental hygienist, the nurse, and the parent-completed questionnaire. Results: Validity was high for screening for caries and treatment needs (>90% for sensitivity, specificity, and predictive values in a sample having 30% to 40% prevalence). Less valid data - mainly an effect of false negatives - were obtained for fluorosis, injuries, and presence of sealants. No significant difference in validity was observed between the nurse and the dental hygienist. One-third of respondents to the questionnaire did not know if their children needed fillings (a proxy for untreated decay) or had received sealants; only knowledge of restorations was comparable to results from screening. Intraexaminer reliability far the two screeners ranged from 85 to 100 for percent agreement and 0.70 to 0.93 for kappa scores. Conclusions: Screening by dental hygienists or nurses can provide valid data far surveillance of dental caries and treatment needs. Training for visual assessment of fluorosis and injuries must be improved to diminish the proportion of false negatives A parent-completed questionnaire is less effective than visual screening for evaluating oral health status in children.