The Oral Hygiene Ability Instrument-OHAI Development and evaluation of an instrument measuring the cause of poor oral hygiene self-care in older adults

Abstract: Oral hygiene is an important preventive measure to maintain good oral health in the growing group of older adults. Oral hygiene often deteriorates with age, but the causes of this at the individual level are rarely investigated. One reason of several may be that a multifactorial assessment instrument is missing. The aim of this thesis was therefore to develop and evaluate an instrument to assess the cause of any inability for older adults to manage daily oral care. The qualitative Study I aimed to identify factors that affect older adults’ ability to manage oral hygiene. Focus group interviews (n = 4) were conducted with dental hygienists, occupational therapists, assistant nurses, and older adults. Data were analysed using content analysis. The results were formulated into the core category “Oral hygiene is a complex activity” that is influenced by psycho-logical, functional, and environmental factors. Inclusion criteria for Studies II-IV were: 1) age ≥ 65 years, 2) at least one natural tooth or osseointegrated implant, and 3) ability to manage oral hygiene independently. Study II describes the development process of the Oral Hygiene Ability Instrument (OHAI), which comprised three phases: planning, construction, and evaluation. The construction phase was based largely on the results of Study I. The evaluation phase resulted in the reduction of OHAI from 47 to 33 items. OHAI came to consist of three parts: Part I – interview, Part II – clinical examination, and Part III – observation of the oral hygiene activity. Based on the results of Parts I-III, the rater (a dental staff member) conducts a summary assessment of the impact of ten factors (cognitive function, frailty, motivation, vision, fine motor skills, coordination knowledge of oral hygiene, spatial ability, oral clearance, and balance) on the individual’s oral hygiene ability. Study III concerned the reliability of OHAI. Part I (interview) was tested for test–retest reliability on 37 older adults. Parts II and III were tested for intra-/interrater reliability. Four dental professionals assessed 15 films and intraoral photos of older adults undergoing OHAI assessment. Parts I and III were found to have acceptable-to-good test-retest and intra-/interrater reliability, respectively; however, five items in Part II displayed limited reliability. In Study IV, the OHAI was tested for criterion and construct validity in a stroke group (n = 50), a group with cognitive impairment (n = 49), and a group of general dental patients (n = 50). Criterion validity was analysed, with sensitivity/ specificity showing acceptable-to-good agreement. To test for construct validity, known-group validity analysis, factor analysis, and Rasch analysis were used. In general, OHAI demonstrated good criterion and construct validity. However, Study IV, like Study III, showed potential for improvement for some items, which meant that some minor changes were implemented in the OHAI to obtain a more robust and easier-to-use instrument. In conclusion, oral hygiene was found to be a complex activity that needs to be supported in different ways depending on the cause of the lack of ability. The development of the OHAI means that there now is a valid and reliable instrument for the assessment of the cause of an older adult’s inability to manage oral hygiene.