Comparing approaches to determining poor oral health among older adults in a national survey.

Objectives: To compare the clinical validity of the three approaches in residential care facility residents.

Background: In NZ residential care facilities, the interRAI assessment tool is used by trained registered nurses for assessing oral status when new residents are admitted, but its validity has been questioned. Although Locker's global oral health item has been used to measure oral health in surveys and health services research, it is not routinely used in care facilities, yet its clinical validity has been demonstrated in population-based samples. Self-perceived oral health need may also be useful.

Materials and methods: Using a secondary analysis of clinical and self-reported data from a national survey of nursing home residents (the 2012 New Zealand Older People's Oral Health Survey, or OPOHS), we compared the validity of Locker's item, the interRAI tool and self-reported treatment need for identifying three key clinical indicators of poor oral health among dentate older adults; those were coronal caries (3+ teeth affected), root caries (1+ teeth affected) and xerostomia. Analyses were conducted using STATA, and survey weighting was used to obtain estimates for a source population of 25-843 individuals.

Results: The prevalence of 3+ teeth with coronal caries was 28.7% (23.9, 34.0), the prevalence of 1+ teeth with root caries was 33.7% (28.7, 39.0), the prevalence of xerostomia was 23.1% (18.4, 28.3). Marked gradients in prevalence risk ratio were seen across different categories of Locker's global oral health item and the interRAI assessment tooth for coronal caries and xerostomia. Locker's global oral health item gave a better fitting model and was more discriminative in detecting coronal caries than the interRAI assessment tool (Lockers AIC = 0.76, interRAI AIC = 0.81). None of the approaches was particularly discriminative for root surface caries experience.

Conclusion: Self-reported approaches are discriminative for poor oral health. Standardised assessment tools used in residential care facilities should consider including a self-assessment component such as Locker's global oral health item.