Oral health of high-cost patients and evaluation of oral health measures as predictors for high-cost patients in South Korea: a population-based cohort study

OBJECTIVE: To examine the oral health conditions and oral health behaviour of high-cost patients and evaluate oral health measures as predictors of future high-cost patients. DESIGN: A retrospective, population-based cohort study using administrative healthcare records. SETTING: The National Health Insurance Service (NHIS) medical check-up database (a.k.a. NHIS—national health screening cohort database) in South Korea. PARTICIPANTS: 131 549 individuals who received biennial health check-ups including dental check-ups in 2011 or 2012, aged 49–88. PRIMARY OUTCOME MEASURES: Current and subsequent year high-cost patient status. RESULTS: High-cost patients, on average, incur higher dental costs, suffer more from periodontal disease, brush their teeth less and use secondary oral hygiene products less. Some of the self-reported oral health behaviours and oral symptom variables show statistically significant associations with subsequent year high-cost patient indicators, even after adjusting for demographic, socioeconomic, medical conditions, and prior healthcare cost and utilisation. CONCLUSIONS: We demonstrate that oral health measures are associated with an increased risk of becoming a high-cost patient.