Assessment of the reliability and validity of the Dental Neglect Scale in Norwegian adults

AIMS: To evaluate the reliability and construct validity of the Dental Neglect Scale (DNS) and to estimate the level of dental neglect in the adult Norwegian population. METHODS: A questionnaire containing socio-demographics, oral health attitude variables, self-reported service use and a translated version of the original DNS was tested in two samples: 1) a convenience sample of University employees (n=263) and 2) a proportionate random sample (n=2000) drawn from the national population register (age 16-79 years). The reliability assessment of the instrument was by internal consistency (Cronbach's alpha) and factor analysis (principal component) (n=1309). The test-retest comparisons (n=108) were analyzed by Spearman's rho for the sum-scores, and kappa statistics for single items. Logistic regression analyses were used to evaluate the construct validity of the DNS. RESULTS: The Cronbach's alpha coefficient for the overall construct of DNS was 0.67 (n=173) and 0.57 (n=1301). Only one factor was extracted, explaining a total of 36% of the scale variance (n=1301). Cohen's kappa for the test-retest comparisons ranged from 0.21-0.79 (n=108), and Spearman's rho for the test-retest sum-scores was 0.60. Higher neglect scores were positively related to a negative opinion about own dental health (OR=3.3), last dental appointment because of pain or other problems (OR=2.3), less than 20 teeth (OR=2.2), drinking soft drinks with sugar every day (OR=2.1), non-regular dental service use (OR=2.2) and using floss or toothpicks seldom or never (OR=1.6). The prevalence of high dental neglect was 20%. CONCLUSIONS: The analyses indicated construct validity for the Dental Neglect Scale but low reliability for some of its items. One fifth of this representative sample of Norwegian adults reported a high level of dental neglect.