Validity of self-reported number of teeth in middle-aged Finnish adults: The Northern Finland Birth Cohort Study 1966

• Main Authors: Nieminen, P. (Author), Similä, T. (Author), Virtanen, J.I (Author)
• Format: Article
• Language: English
• Published: BioMed Central Ltd. 2018
• Subjects: Adult; Cross-Sectional Studies; cross-sectional study; female; Female; Finland; human; Humans; Longitudinal Studies; longitudinal study; male; Male; middle aged; Middle Aged; periodontal disease; psychology; questionnaire; reproducibility; Reproducibility of Results; self report; Self report; Self Report; Surveys and Questionnaires; Tooth; Tooth loss; Tooth Loss; Validity
• Online Access: View Fulltext in Publisher

 Background: We examined the validity of self-reported number of teeth in middle-aged adults by using representative cohort data to compare corresponding self-reported and clinical values. Methods: This validity study is part of the representative 46-year-old follow-up of the Northern Finland Birth Cohort 1966 (NFBC1966) Study. Mailed questionnaires (n=5950) requested information on self-reported number of teeth and background variables (education, tooth brushing and smoking), while clinical oral health examinations (n=1891) assessed the number of teeth (the 'gold standard'). The main analyses compared the self-reported and clinical values for the number of teeth in 1669 participants. Scatterplot and Bland-Altman plot served for visual analyses, and alternative correlation coefficients (Pearson, Spearman, intraclass) for numerical comparisons separately for men and women, with stratification according to background variables. Results: The clinical assessment revealed that the mean value for the number of teeth was 27.46 (SD=2.38), while the corresponding value based on self-reported information was 27.48 (SD=2.78). According to the Bland-Altman plot, the mean difference between the clinical and self-reported values was 0.02 (95% limits of agreement, LoA: 3.37 to 3.32). The observed ranges of intraclass correlation coefficients (ICC) among men and women were 0.72 to 0.95 and 0.72 to 0.85, respectively, depending on the background variables. Conclusions: Self-reported number of teeth in middle-aged Finnish adults agreed closely with the corresponding clinical measure. © 2018 The Author(s).