Study design
This semi-experimental study was conducted on all people (aged 30–59 years) referring to the primary health care centers of Jahorm city located in Fars province of southern Iran from September 2021 to July 2022. A relatively high level of obesity and cardiovascular problems have been recorded in people over 30 years old in Jahrom city [
18]. Primary health care centers are the first level of community contact to receive preventive and therapeutic services in Iran. In these centers, accessing the community’s people and implementing health education programs is possible.
Assuming a target difference of 0.4, SD 0.5, and standard difference of 0.8, and taking into account the confidence interval of 95% and power of 80% [
19], and assuming the equal number of samples in both groups using Altman Nomogram, the sample size in the intervention and control groups was calculated to be 50 people (100 people in total). Sampling was a multistage cluster random sampling in which primary health care centers of Jahrom city were considered as separate clusters, and two centers were randomly selected. Then, to prevent contact between the intervention group and the control group and the transfer of educational content between the two groups, one center for the intervention group and another for the control group were randomly selected. In the next stage, the study participants were randomly chosen among the all people (aged 30–59 years) referring to each center. Inclusion criteria include All men and women (30–59 years old) referring to primary health care centers in Jahrom city who did not have a confirmed history of CVD. Exclusion criteria include Failure to complete the written consent form to participate in the study, Failure to respond to the questionnaires fully, and absence of more than one session in the educational program in the intervention group.
Instrument and data collection
The questionnaire used in this study was designed by Tavassoli et al. in 2013 in Iran, and its validity and reliability were measured [
19]. This questionnaire was based on the HBM, and the first part included questions related to demographic characteristics (gender, age, education level, family size, marital status, occupation, average monthly household income, and smoking), the second part included six knowledge questions, four perceived susceptibility (person’s perception of the possibility of danger) questions, four perceived severity person’s (perception of the seriousness of the risk) questions, three perceived benefits (person’s perception of the effectiveness of measures to reduce the risk of the disease) questions, and seven perceived barriers (person’s perception of the obstacles to performing health measures) questions. In the knowledge questions, the correct answer was given a score of 1; the rest were zero; the highest score was 6, and the lowest score was zero. The questions of perceived susceptibility, perceived severity, perceived benefits, and perceived barriers were designed as a 5-point Likert scale (completely agree, agree, neither agree nor disagree, disagree, and completely disagree). The highest score for each perceived susceptibility and severity construct was 20, and the lowest was 4. The highest score for the perceived benefits construct was 15, the lowest score was 3, the highest score for the perceived barriers construct was 35, and the lowest score was 7. To check the reliability of the questionnaire in this study, 30 people (aged 30–59 years) completed the questionnaire, and its reliability was measured using Cronbach’s alpha scale. The values obtained for knowledge were 0.77, perceived sensitivity 0.8, perceived severity 0.82, perceived benefits question 0.91, perceived barriers 0.79, and the whole questionnaire was 0.82.
Also, to measure people’s practice in the field of diet, the food consumption frequency checklist was used, which was prepared in the form of consumption of each of the desired foods with daily, weekly, and never options. (Have you consumed the following foods in the past week? How many times if used? Milk, yogurt, cream, jam/honey, cheese, bread, baguette, rice, all kinds of kebabs, pasta, chicken, fish, canned fish, lentils/beans, sausages, eggs, stews, soups, broth, potatoes, pizza, pickles, tomatoes, citrus fruits, other fruits, puffs, sweets, Nuts, ice cream, chocolate, tea, coffee, soda, dates, tamarind).
To complete the questionnaires, the people of the intervention and control groups were invited to the primary health care centers, and they completed the questionnaires under the supervision of the interviewers. At first, the study’s objectives were explained to the participants, who completed a written consent form. Then, the questionnaires were conducted by the people of the intervention and control groups. Then, the obtained information was analyzed, and educational materials and content were prepared based on educational objectives, using reliable sources and with the advice of cardiologists. Educational content regarding nutritional behaviors to prevent CVD was designed as HBM constructs. Then, the educational intervention was done for the intervention group, while no intervention was done for the control group.
Educational intervention
Educational content was designed to improve nutritional behaviors to prevent CVD based on HBM constructs. The content included the following: low-fat diets, including low-fat meats low-fat dairy products, and emphasizing daily consumption of vegetables and fruits. A low-carb diet contains recommendations for a Mediterranean diet, including high consumption of omega-3 fatty acids from fish and plant sources, consumption of fruits, fresh seasonal vegetables, whole meal bread and cereals, nuts, olive oil, and legumes; Providing body protein from fish, chicken and eggs instead of red meat. Avoid harmful substances, including salt, sweets, carbonated drinks, and alcohol [
20‐
22]. The educational content was reviewed and approved by a nutritionist and a cardiologist.
The educational intervention included holding four sessions, each lasting for 60 min. The methods used for training included lectures, questions and answers, and group discussions. Pamphlets and text messages were also used to repeat educational materials. Training sessions were held weekly. SMS was sent twice to each person in the interval between meetings. After the end of the training sessions, sending SMS twice a week continued for a month. At the end of the research, a training course was held to improve CVD prevention nutritional behaviors for the control group.
The people of the intervention and control groups were invited to the primary health care centers three months after the completion of the educational intervention, and the questionnaires were filled out again by them. It should be noted that this was the last stage of follow-up and completion of the questionnaire by the participants.