Assessing the impact of an educational intervention program based on the theory of planned behavior on the nutritional behaviors of adolescents and young adults with PCOS in Iran: a field trial study

This field trial study (IRCT20160224026756N6) was a part of a mixed-method study and conducted on the two groups (intervention and control) in 2018 [17]. In order to obtain an easier access to adolescents and young adults with PCOS from different cultural and social classes, the present study was performed in four gynecology clinics affiliated to Shiraz University of Medical Sciences, Iran. Based on the confidence interval of 95%, a test power of 80%, the standard deviation of 0.1 to 0.25 [18], a sample loss rate of 10%, and the equation used for sample size calculation \(N=\frac{\left(Z_{1-{\displaystyle\frac\alpha2}+}Z_{1-\frac\beta2}\right)^2\left(S_1^2+S_2^2\right)}{\left(X_1-X_2\right)^2}\) a total of 36 people were estimated for each group.

In the current study, the inclusion criteria were as follows: (i) single overweight (with a body mass index (BMI) of 25 or more) or obese (with a body mass index of 30 or more) adolescents and young adults aged between 15 and 21 years old [19] with PCOS; (ii) diagnosis of PCOS by a gynecologist in terms of the diagnostic criteria [1]; (iii) without a history of any known psychiatric disorders under medical treatment; (iv) without a history of any known chronic disease such as diabetes, cardiovascular, and kidney disease; (v) without having any special diet prescribed by a doctor; vi) not participating in other clinical trials simultaneously; and (vii) participating in educational course sessions with a healthy peer. The exclusion criteria were the absence in more than 2 sessions of the educational classes, lack of willingness to continue cooperating in research, and using special diets during conducting this research.

In this study, the sampling method used was convenience, so that the medical files of 284 adolescents and young adults with PCOS were evaluated and participants who met the inclusion criteria were selected in the gynecology clinics. Subsequently, after making phone calls to them, the time of each visit was settled. Among the 137 adolescents and young adults with PCOS referred to the four study clinics, 72 subjects were registered and after obtaining written consent, they were enrolled in the study (Fig. 1). In this study, 18 participants were selected from each clinic. The allocation of these people to the intervention and control groups was performed based on the order of their admission to the clinic. In each clinic, the first person was accepted and then assigned to the intervention group, and the second person was assigned to the control group, and by repeating this manner, the allocation process continued up to the end. In this study, after necessary coordination with the participants in the intervention group, the educational intervention program was performed based on the TPB in four sessions (60 to 90 min) during two weeks (two sessions per week). The researcher asked the participants to attend the training sessions at the patient education unit in one of the gynecology clinics with a suitable environment for training. At the end of the study, the participants' travel expenses were reimbursed and they were then appreciated by a gift. To improve the educational process during the training sessions, adolescents and young adults with PCOS (who were invited along with a same-sex healthy peer) were divided into three groups each one consisting of 12 participants. Peer attendance at the training sessions could help the participants understand why their peers want to change their nutritional behavior and support them in this regard [20]. The sessions included lectures, group discussions, questions and answers, role-playing, movies, brain storming, and practical display. Moreover, some strategies and activities were performed in the educational intervention program, which are presented in Table 1. In the present study, an educational session was also performed for the included participants’ mothers (without the presence of their daughters) to explain the principles of nutrition, healthy nutritional behaviors, PCOS and its side effects, and the effect of healthy nutrition on the treatment of PCOS, and finally an educational booklet was given to them. The participants in the control group received no training and they only completed the questionnaires at two stages. In this regard, a training booklet was given to them and also, if necessary, they were referred to a nutritionist after the end of the study. At this stage, by passing three months from the completion of the educational intervention, the researcher sent reminder messages once a week by forming a group in WhatsApp Messenger to follow the activities and nutritional behaviors of the participants included in the intervention group. Correspondingly, these messages were related to the topics and key points presented in the training sessions. Consequently, this provided a platform for questions and answers as well as the transfer of participants' experiences about their nutritional behaviors. Take advantage of this social media created a suitable platform for participants to communicate with the researcher easily if they need any further information.

In this study, the primary outcomes were knowledge, attitude, subjective norms, and perceived behavioral control about disease-related nutritional behaviors; intention for healthy nutritional behaviors; and participants' nutritional behaviors that were previously measured by the researcher-made questionnaires at two stages (once before the intervention and once three months after the intervention). The above-mentioned questionnaires contained demographic characteristics; knowledge about disease-related nutritional behaviors; attitude, subjective norms, and perceived behavioral control about the disease-related nutritional behaviors; intention for having healthy nutritional behaviors; and the consumption of food groups, fast food, and snacks. The demographic profile questionnaire was used to assess the participant’s age, occupation, and level of education, as well as parental employment status and educational level. The other questionnaires (used to measure knowledge, attitude, subjective norms, the perceived behavioral control, intention for healthy nutritional behaviors, and nutritional behaviors) were designed by studying the existing articles and resources based on the current research objectives [21, 22]. In the knowledge measurement about the disease-related nutritional behaviors, 11 questions (right, wrong, and I'm not sure) were used with a score of zero for not sure, or the wrong answer and score of one for the correct answer. Notably, the minimum knowledge score was zero and the maximum one was 11. Attitude about disease-related nutritional behaviors with 9 questions, subjective norms with 6 questions, perceived behavioral control with 7 questions, and intention for healthy nutritional behaviors with 8 questions were measured in a five-point Likert scale. The attitude scores ranged from 9 to 45, the subjective norms scores ranged from 6 to 30, the perceived behavioral control scores ranged from 7 to 35, and the intention for healthy nutritional behaviors scores ranged from 8 to 40.

The participants were asked to report the frequency of the consumption of fast food, sandwiches, snacks, and other food groups including bread and cereals, fruits and vegetables, milk and dairy products, legumes, nuts, and oily seeds (according to the specified daily share among the adolescent and young adults age groups [19]) during the past week. For designing the initial format of the questionnaire, the study by Keshani et al. [23] was used. Thereafter, using the opinion of nutritionists and by taking the nutritional needs of adolescents and young adults into account based on the food groups [19, 24, 25], changes were made in the questionnaire, which was finally designed with 11 items in the form of a 4-point Likert scale. In terms of nutritional behaviors, scoring for the consumption of fast food and snacks was "I never consume" as score 4, "sometimes I consume" (1–2 times a week,) as score 3, "I often consume" (3–4 times a week) as score 2 and "I always consume (equal to or more than 5 times a week)" as score 1. Regarding the food groups, scoring was done reversely. The range of nutritional behaviors was between 11 and 44. To validate the data collection tools, the content validity method was used and to determine the reliability of the questionnaires, the test–retest was used and Pearson correlation coefficient equal to 0.76 confirmed the reliability of the data collection tools.

Research ethics confirmation (ethical approval code: ethics code: IR.MUI.Rec.1395.3.885) was received from the Ethics Committee of Isfahan University of Medical Sciences. Written informed consent from the adolescent and her parents (in cases younger than 18 years old), anonymity, confidentiality, and the right of leaving the research at any time were preserved.

The results showed that the mean scores of knowledge, attitude, subjective norms, the perceived behavioral control about the disease-related nutritional behaviors, intention for healthy nutritional behaviors, and nutritional behaviors had statistically significant differences before and after the intervention in the intervention group, but no significant difference was observed in the control group (Table 3). As well, the results showed that the mean scores of knowledge, attitude, subjective norms, the perceived behavioral control about disease-related nutritional behaviors, intention for healthy nutritional behaviors, and nutritional behaviors had no statistically significant differences between the two groups before the intervention. But, the mean difference of scores of knowledge, attitude, subjective norms, the perceived behavioral control, behavioral intention, and nutritional behavior had a statistically significant difference between the two intervention and control groups (Table 4).

The results of the present study showed that the frequency of the consumption of pizza, sandwiches, hamburgers, hot dogs, and all kinds of snacks by the participants in the intervention group decreased by passing three months from the start of the educational intervention compared to before the intervention and these differences were statistically significant (P < 0.001). In addition, the frequency of the consumption of food groups, including fruits and vegetables; milk and dairy products; and meat, seafood, legumes, and eggs increased in the participants of the intervention group by passing three months from the intervention compared to before the intervention, and these differences were statistically significant (P < 0.001) (Table 5).

According to the obtained results, the application of the educational intervention program based on the TPB is effective on promoting the nutritional behaviors of adolescents and young adults with PCOS. Therefore, findings of the present study can be useful in designing and improving the educational programs available in the health system for educating adolescents and young adults with PCOS. Using this educational program can consequently empower adolescents and young adults with PCOS to adopt healthy nutritional behaviors and also to promote their nutritional health status and ultimately their reproductive health.

One of the strengths of this study was the implementation of educational intervention program based on the TPB for the adolescents and young adults with PCOS for the first time. One of the limitations of the present study was the assessment period of the educational program’s results, which was considered as three months after the intervention. However, in order to better assess the results of the educational intervention program, the follow-up period can be considered as longer in future studies. As well, in this study, the assessment of the final nutritional behavior was done based on the self-report of the participants, so it could have bias. In this regard, in future studies, a combination of self-reporting method, direct observation of behavior, and report by parents or teachers can be used if possible. In the present study, due to the convenience sampling and the possibility of selection bias, generalization of the results to a larger population of adolescents and young adults with PCOS may not be possible. Furthermore, since this study was non-blinded, this was another limitation that may have led to reporting bias. Also, in this field trial study, we faced a multiple testing problem which could have an impact on error rates, leading to inappropriate interpretation of the results.