RELIABILITY OF A SELF-REPORTED HEALTH QUESTIONNAIRE IN A PERIODONTAL-DISEASE STUDY

This study assesses the reliability of a self-reported health question naire completed by 413 subjects aged 25-74 yr in the Erie County Perio dontal Disease (ECPD) Study. Specific questions on general and oral he alth conditions were completed by each subject during a first visit an d at a followup examination 2 yr later, and the two compared. Results showed that the overall measure of agreement between the two visits is substantial (average kappa, kappa=0.80). Variation by gender and age were minimal. Questions regarding allergy to medications, oral treatme nt, reason for tooth extraction, health symptoms and history of system ic diseases exhibited high levels of agreement (kappa ranged from 0.71 -0.90). Information on vitamin and mineral intake yielded kappa=0.63. Oral conditions scored the lowest but were still acceptable (kappa=0.5 7). These findings indicate that there were no significant discrepanci es in self-reported responses to the health questionnaire used in the ECPD Study. Although the information provided by the subject may not b e as accurate as compared to laboratory testing, it is nevertheless a reliable source of information which can be utilized cost-effectively in research studies.