Design, procedure and the study sample
This study was conducted as an educational randomized controlled trial (single blind) on patients with diabetes referring to the county diabetes clinic in the city of Kashan, Iran from 2017 to 2018. From a total of 2500 diabetic patients referred to diabetic clinic, 120 patients who met the study’s inclusion criteria were randomly assigned into intervention and control groups (60 participants in each group).
According to the study by Baghiani Moghadam et al. [15] considering a = 5% and β =0.1.
Based on the following formula, the sample size was 58 patients in each convention and control group, which increased to 60 patients. Thus, the total number of samples was 120 patients. (see Formula 1 in the Supplementary Files)
In this study having means of 10.8 and 12.42 and standard deviations of 2.79 and 2.57 for the intervention group before and after the intervention respectively for perceived susceptibility construct in Baghiani Moghadam et al. [15], an effect rate of 0.6 was obtained indicating a large effect size and the same effect rate was considered for this study.
Of the patients who had medical records at the clinic, 120 were selected through systematic sampling and were randomly (every other person) assigned to the intervention (n= 60) and control (n = 60) groups through the rules of random allocation. Then the pre-test was administered to both groups based on the questionnaire. The intervention group received trainings based on HBM and the control group received routine cares. Then the patient were followed up for three months. After that the post-test was administrated and finally the effect of education on their oral and dental hygiene related behavior was re-evaluated. In this study the primary outcomes were constructs of HBM (perceived susceptibility, severity, benefits, barriers, cues to action, and self-efficacy) and secondary outcomes were oral and dental health behaviors.
According to Panel of Experts, three months of follow-up was considered sufficient time to establish consistency, stability, and sustainability in oral health care behaviors.
Inclusion criteria for the study included having medical records in the diabetes clinic, being between 40-60 years old, being literate, residing in Kashan, having no oral symptoms, having no history of radiotherapy and hemodialysis, having no other chronic systemic diseases, not taking any drugs that have side effects such as dry mouth, not wearing dentures, and signing an informed written consent. Exclusion criteria included having no desire to participate in the study, moving from Kashan to another city, not attending the training sessions regularly, and suffering from any other systemic disease.
The conceptual framework of the study was that according to the inclusion criteria, the samples referred to diabetes clinic were selected and then divided into intervention and control groups.. Then the pre-test was administered to both groups based on the questionnaire. After that the intervention group received trainings based on Health Belief Model. Using the perceived susceptibility construct, patients initially felt at risk of oral and dental problems and understood the complications and at the same time they were taught the benefits and barriers of preventive behaviors. Oral care-related behaviors were then taught using internal and external cues to action and increasing patients' self-efficacy. The control group received routine diabetes clinic trainings. Then the patients were followed up for three months and then the post-test was administrated and the effect of education on their preventive behaviors was re-assessed. Figure 2 shows the study diagrams.
Measures
The data collection tool in this study was a valid and reliable researcher-made questionnaire consisting of questions on demographic information, awareness, constructs of the Health Belief Model, and performance in oral hygiene-related behaviors in patients with T2DM. The validity and reliability of this questionnaire was approved and it was completed by both control and intervention groups before the educational intervention and three month after the educational intervention. In this tool, those questions with a Content Validity Ratio (CVR) greater than 0.62 and a Content Validity Index (CVI) greater than 0.79 were considered appropriate and were included in the study [16].
To confirm the reliability, the questionnaire was completed by 30 diabetic patients, and its reliability was 0.866 using Cronbach alpha. The validity of the questionnaire was also confirmed by three health education experts, three internal diseases specialists, an endocrinologist, a dentist, and an expert having a PhD in epidemiology and an executive focal point in the National Program for Prevention and Control of Diabetes in Iran after removing or modifying some of its statements.
The questionnaire of diabetic patients’ awareness of oral care consisted of 9 questions. Constructs of HBM questionnaire of oral hygiene-related behaviors consisted of perceived susceptibility (7 questions), perceived severity (10 questions), perceived barriers (7 questions), perceived benefits (8 questions), self-efficacy (11 questions), internal cues to action (triggers) (4 questions), and external cues to action (5 questions). The questionnaire of performance on oral hygiene-related behaviors also consisted of 10 questions.
Scoring
In the awareness questions section, for each correct answer, a score of 1 and for each false answer, a score of 0 was considered, and the total score of the awareness section was calculated based on score 9. The Health Belief Model constructs questions were scored on a five-point Likert scale, with the answers being "strongly agree, agree, no idea, disagree and strongly disagree" from 1 to 5, respectively. Therefore the scores range of each model construct was finally calculated and reported between one and five.
The questions of performance questionnaire were scored on a 5-point Likert scale of behavior evaluation with the answers being “never, rarely, sometimes, often and always” from 0 to 4.
In this study higher score indicate higher level of awareness, perceived susceptibility, perceived severity, perceived benefits, perceived barriers, cues to action, self-efficacy, and performance of oral hygiene in diabetic patients.
Intervention
Before performing the educational intervention and in pre-test step, the questionnaires were completed by both groups and entered the computer to determine patients' educational needs and to determine the need for training of different structures in educational sessions.
Then, according to Health Belief Model and based on the results of the need assessment, the training program was prepared for four 120-minute sessions in one month targeted at the intervention group. The materials were presented in the sessions through lectures, question and answer, Power Point slides presentation, and leaflets and booklets were provided for easier access of patients to educational resources during the study.
In the first training intervention sessions, the awareness of diabetic patients was emphasized with the aim of achieving better knowledge of diabetes and factors affecting deterioration and acceleration of oral complications. The second session's focus was on perceived susceptibility and severity was touched by presenting the statistics on prevalence of oral problems resulted from diabetes and vulnerability of patients and severity of oral complications resulted from inappropriate blood sugar control and not performing oral hygiene-related behaviors. The third session's focus was on perceived benefits, perceived barriers, and cues to action. The materials of this session emphasized on the benefits resulted from performing oral hygiene-related behaviors (reduced oral complications, decreased visit to the dentist and lower medical expenses, feeling the inner peace and joy), identifying and removing perceived barriers through performing oral hygiene-related behaviors (unawareness, physical weakness, fatigue, feeling bored, etc.), external cues to action affecting performing oral hygiene-related behaviors (including physicians, diabetes clinic nurses, family members, television, books and magazines in health centers, other diabetic patients), and the role of internal cues to action or triggers (motivation and inner peace resulted from performing hygiene-related behaviors).
The fourth session's focus was on perceived self-efficacy and performance of oral and dental health hygiene behaviors. Self-efficacy construct was emphasized by empowering the patients to facilitate oral health care through presenting educational images on PowerPoint slides, practical training, distributing packages containing a toothbrush, a toothpaste and a dental floss among the patients, and providing them with booklets and leaflets. In the performance section the following behaviors were taught to the patients: brushing teeth, using dental floss, washing tongue, massaging gums, performing preventive behaviors and being aware of the possible oral complications of diabetes.
In this study, the control group received only routine care which included a monthly visit by a doctor, public health educators, a dietitian, and a nurse for less than 20 to 30 minutes at a clinic.
Three months after the educational intervention, the questionnaires were again completed by both groups.
Statistical analysis
The data were analyzed using SPSS version 20 through descriptive statistics (Mean, SD, frequency, and percent) and inferential statistics (including independent t-test, paired t-test, Chi-square). To investigate the normality of the data, Kolmogorov-Smirnov test was used and normal distribution of the data was obtained. Concerning the gender difference between diabetic men and women with regard to oral hygiene behaviors (which the reviewer considered), and also due to the small size of the groups (men and women), the distribution of data was non normal and therefore nonparametric tests (Wilcoxon and Mann-Whitney) were used.