Abstract
More knowledge is needed regarding what works to prevent oral health problems and reduce disparities in oral health. Motivational interviewing (MI) has demonstrated utility for improving health behavior, including among those with severe mental illness. This study tests whether MI enhances the efficacy of an oral health education intervention in individuals with severe mental illness. Sixty individuals were randomly assigned to MI plus oral health education or oral health education alone. Plaque scores, oral health knowledge, and self regulation were assessed at baseline and at 4 and 8 weeks. Repeated measures ANOVA showed improvement (p < 0.05) in plaque, autonomous regulation, and oral health knowledge across time for both groups; however, individuals receiving MI improved significantly more when compared with those receiving oral health education alone. Results suggest that MI is effective for enhancing short-term oral health behavior change for people with severe mental illness and may be useful for the general population.
Introduction
There have been numerous calls for improving our knowledge of what works to prevent oral health problems and to reduce disparities in oral health status experienced by disadvantaged groups. For those with severe mental illness, the illness and xerostomia associated pharmacological management puts individuals at greater risk for tooth decay, periodontal diseases, and increased requirements for periodontal treatment, dental restorations, and dental extractions. schizophrenia in individuals with severe mental illness may affect their ability and desire to perform preventive oral hygiene procedures. Furthermore, increased use of candy, chewing gum, and carbonated beverages to combat xerostomia can further promote tooth decay. Consequently, preventive dental education is particularly important for people with severe mental illness. Although dental health education has positive effects on plaque accumulation and knowledge level, effects are relatively weak and may be short-lived. The effects of educational interventions may be improved by enhancing individuals’ motivation to implement and maintain behavioral changes. Motivational interviewing (MI) is effective in enhancing motivation for changing a wide range of health behaviors, including oral hygiene. MI uses specific methods to elicit the individual’s “internal” motivation to foster autonomous self-regulation, rather than the practitioner providing “external” reasons to persuade the individual to change. The purpose of this study was to investigate whether providing a brief MI session immediately before an oral health education session would enhance the education effect. It was hypothesized that MI plus oral health education would reduce plaque scores and improve knowledge and autonomous self-regulation more than would oral health education alone, at the four and eight week follow ups.
Methods
Sample Adults (N = 60) with severe mental illness, with at least 1 gradable tooth in each sextant, were recruited from a community program. Sample size was determined through power analysis. Variance estimates for the primary outcome measure, plaque scores, were based on our previous study, with a meaningful difference of 15% set for effect size, with alpha at 0.05 and power (1-β) at 0.80. Participants were randomly assigned to treatment groups by a scientist not directly involved in study implementation or data collection. Simple random assignment was accomplished by means of a random numbers table. Individuals were excluded for obvious periodontal disease, orthodontic appliances, significant physical or cognitive disabilities, not having access to a ‘phone, or currently using a mechanical toothbrush. This study was approved by the University of Kansas Medical School Institutional Review Board, and all participants provided full and informed consent.
All measures were obtained at baseline and 4 and 8 weeks following intervention. We used the 'Modified Quigley-Hein Plaque Index' to score the primary outcome variable, plaque accumulation, on the oral and lingual surfaces of 'Ramfjord’s teeth' at each time point. If any of these teeth was missing or not gradable, the closest tooth was graded. We obtained a person level plaque score by averaging plaque scores for all teeth at each visit. A single examiner, who was calibrated to a “gold standard” examiner prior to study implementation, conducted all oral examinations. Although the examiner was not blind to group assignment, a blinded validity check on 10 randomly selected participants (5 per group) at the eight week appointment by the gold standard examiner revealed very high reliability between examiners (r = 0.976). A 15 item Oral Health Knowledge questionnaire was developed and evaluated for face validity by a panel of three clinicians with expertise in survey methods, and then pilot tested in a sample of five individuals with severe mental illness to ensure that participants could understand the questions. Possible scores ranged from 0 to 34. The questionnaire was shown to possess good internal consistency. We used the Treatment Self-regulation Questionnaire (TSRQ) concerning oral hygiene to assess each participant’s self-regulation for brushing his/her teeth regularly. The 'TSRQ' has adequate reliability and validity. The measure includes 2 sub scales (4 items each) assessing “autonomous” and “controlled regulation”. Autonomous regulation represents internalized motivation based on personal importance and a sense of acting in congruence with one’s values and needs. Controlled self-regulation is less internalized and is based on external rewards and punishments, or to avoid guilt or anxiety.