Mind the gap: an administrative data analysis of dental treatment outcomes and severe mental illness.

Background: Oral health of people with severe mental illness (SMI) remains an important public health issue, despite evidence pointing suboptimal dental health outcomes in this population.

Aims: We test the hypotheses that individuals with SMI have lower contact with dental services and higher levels of fillings and extractions. We also examine effect modification by age-group.

Methods: We used linked administrative data from general practitioner (GP), hospital and dental records to examine dental service use and treatments (extractions, fillings, crowns and x-rays) among the Northern Ireland hospital population between January 2015 and November 2019 (N = 798,564).

Results: After adjusting for available socio-demographic characteristics, analysis indicated lower levels of dental service use (OR = 0.80, 95% CI = 0.77, 0.84), including lower likelihood of fillings (OR = 0.81, 0.77, 0.84) and x-rays (OR = 0.77, 0.74, 0.81), but higher levels of extractions (OR = 1.23, 1.18, 1.29) among patients with SMI. We also found effect modification by age-group, with older individuals with SMI less likely to have each of the four dental treatments.

Conclusions: We suggest that in the general area of physical healthcare for people with SMI, oral healthcare is neglected. There is a need for improved understanding of the barriers to routine care and treatment, and development of psychoeducational interventions.