This study was a randomized controlled trial conducted on 120 students of Islamic Azad University, Shahr Rey Branch, Tehran, Iran, in 2016. The correlation between the health literacy and quality of life of students was assessed through an analytic descriptive pilot study on 300 students. The findings of the pilot study showed a significant relationship between the total, physical, and mental health scores in quality of life of students and their health literacy level (P<0.05).

Students were included if they were aged between 18 and 25 years and at least in the second year of their college study. Exclusion criteria were an above-average quality of life score and lack of interest to participate in the study.

The sample size of the second stage of the study (intervention phase) was estimated by using the Kappa formula, considering a confidence level of 95% and study power of 80%. The pilot showed that the mean score of students’ health literacy was 0.7; therefore, the calculated sample size was 60 participants for each group (considering a 10% dropout rate). Cluster random sampling was used to select the participants. In this method, three faculties were chosen from all faculties at the Islamic Azad University, Shahr Rey Branch, using a table of random numbers. Five classrooms were selected systematically from each selected faculty. Sampling was performed in two stages: first, the samples were selected with convenience sampling from these classes for the descriptive phase; second, students whose quality of life scores were less than the mean score and who agreed to participate in the study were selected for the interventional phase. The participants were then categorized into subgroups based on the main study factors, including marital status and health condition. Finally, an equal number of participants was randomly assigned into the experimental and control groups, with similar distribution of marital status and health condition.

In this study, data collection (pre-test and post-test) was conducted through self-report questionnaires. The questionnaire had three parts: the demographic questionnaire, Test of Functional Health Literacy in Adults (TOFHLA), and Short Form-12 questionnaire of life quality (SF-12). The demographic questionnaire included questions on age, sex, marital status, educational level, employment status, job satisfaction, family income, and health status. TOFHLA was used to determine the health literacy of the participants. Javadzade et al. [4] assessed its psychometric properties in Iran. The reliability of the numeracy and reading comprehension parts was reported as 0.79 and 0.88, respectively. The health literacy score of each participant could be in the range of 0–100: 1–59, inadequate; 60–74, borderline; and 75–100, adequate. SF-12, which was designed in 1996 by Ware et al. [15] was used to define the participants’ health-related quality of life. Montazeri et al. [16] assessed its psychometric properties in Iran in 2009. The reliability of the physical and mental components was reported as 0.73 and 0.72, respectively. A score of 12–24 was considered ‘poor life quality,’ 25–36, ‘average life quality,’ and 37–48, ‘good life quality.’ [16]

The research objectives were explained to the target group, who were subsequently assured of the confidentiality of information. Written consent was obtained from all of the participants. Then, the questionnaires were distributed and completed by the students. Educational programs were provided to the case group, whereas the control group received no intervention. The design and implementation of the educational intervention was performed with regard to health literacy strategies (HLS) [17]. To this end, an educational session was held using HLS to improve verbal communication (such as teach-back technique).

According to the target population poll on the preferred educational tools and surveys on university students, online messaging services such as Telegram, WhatsApp, and Line were considered as the most suitable methods to transfer message in terms of access to information, cost, ease of training, and scope of context or situation. Another finding was the unwillingness of students to turn to traditional teaching methods (lectures) owing to their being time consuming and interference with class hours.

In this research, the contents of the educational intervention were designed based on a health literacy needs assessment conducted using three sources of information: experts’ opinion, target group’s ideas, and literature review. The opinions of experts (health educator professionals and professor) and the target group were collected through interviews and focus group discussions, respectively. Through literature review, we explored, delineated, and analyzed the current national and international literature with respect to the various aspects of the problem. In this phase of study, the educational needs were determined in two major domains: physiological and psychological. Physical health education consisted of the perception of health, physical performance, physical health, and physical pain. The psychological domain included emotional issues, social performance, vitality, and mental health. These domains were chosen through need assessment phase which is expresed in this section.

Generally, the specific lesson plans were designed to contain six sessions. The first session, lasting about 2 hours, was held in one of the university classes by the health educator (first author) using the three educational methods of lecture, brainstorming, and buzz groups. Buzz groups are a method for quickly and efficiently gathering feedback on a topic or responding to a specific question during a plenary (a session that includes all participants of an event). The succeeding five sessions were held via social networking services. Educational messages were designed based on the ‘Simply Put’ manual [17] and design manual of health literacy-based print media [18]. Accordingly, the readability level of the messages and intended educational materials were set using Simple Measure of Gobbledygook (SMOG) [17]. This formula is the fastest strategy to test the readability level of educational contents. Based on the SMOG guideline, we randomly counted the number of words with three or more syllables in 10 sentences in different parts of the text. Then, the square root of the number was calculated, and 3 was added to the calculated number. Finally, based on the provided table, the level and degree of approximation and predicted grade level were identified. In this study, post-test was performed in two steps: immediately and 3 months after the intervention.

The data were analyzed using SPSS ver. 16.0 (SPSS Inc., Chicago, IL, USA). Data were assessed for normality using the Kolmogorov–Smirnov test. Continuous data between groups were presented as means and standard deviations using independent t-test, whereas categorical data were presented as frequency and percentage values using the chi-square test. For the comparison of parametric continuous data, repeated measures analysis of variance with Tukey’s test as post hoc test was used. The significance level was set at 0.05.

This study was approved by the Ethics Committee of the Research Deputy at Tarbiat Modares University (IRB approval no., 6585). Also each participant signed the written informed consent letter before the interview.

The present study showed the significant effect of delivering educational interventions via social networking services, which can be applied in health educational programs. The effectiveness of internetbased education in young people can serve as a basis for developing health literacy-enhancing interventions and capturing the different dimensions of health literacy within the health care, disease prevention, and health promotion settings.

The self-report method of completing questionnaires could cause over- or under-estimation of the results and thereby limit the results of the study. The instructors who agreed to participate in the study were few and not representative. Moreover, psychological differences were not controllable in this study. Thus, it is recommended that further studies take into account measures to assess the effect of psychological factors on the learning process in health education through social networking services.