This was a randomized controlled trial (parallel design) in which 110 middle-aged women with physical inactivity were recruited and randomly assigned into two groups of text messaging and using social media to receive intervention for promoting physical activity. The inclusion criteria were age range of 40-60 years, basic digital literacy, having smart phone, access to the Internet, low score of International Physical Activity Questionnaire (IPAQ) or score of metabolic equivalent (MET)<600 per week. Women with following criteria were excluded from the study: prohibition from physical activity for medical reasons including class 3 and 4 heart disease, and severe arthritis, receiving another training program for physical activity, membership in a gym, and pregnancy.
The design of this study was approved by the Ethics Committee of Ahvaz Jundishapur University of Medical Sciences (Ref. No: IR.AJUMS.REC.1396.727) and the protocol was registered in the Iranian Registry of Randomized Clinical Trials (IRCT) (Ref. No: IRCT20170916036223N1, 29/12/2017). All participants provided written informed consent before data collection. This study started in November 2018 and completed in March 2019.
Sample size
The following formula was used for sample size calculation:
We considered 25% for attrition and the total sample size was calculated to be 55.
Recruitment
Middle aged women that had been registered in two centers (a Menopausal Counseling clinic and a public health center) in Ahvaz, Iran received a phone call requesting them to participating in the study. A total of 131 women were assessed according to the eligibility criteria, of whom 110 were eligible and provided their consent to participate.
Randomization
A random table generated by EXCEL was used for randomization (done by the study statistician). Due to the nature of this study, blinding of participants and researchers was not possible, but the code dedicated to each participant was kept with the secretary of the menopausal clinic, and neither the researcher nor the participants knew the code until the commencement of the trial.
Measurements
A demographic questionnaire, a check list, and the International Physical Activity Questionnaire (IPAQ) were used for data collection. The demographic questionnaire included questions on age, age of menopause, level of schooling, marital status, occupation and number of children. The checklist was used to record anthropometric indices (height, weight, body mass index, waist circumference, hip circumference, waist/hip ratio, and percentage of body fat).
IPAQ contains 7 questions about physical activity over the past 7 days. It has three domains including physical activity related to work, leisure time, and home. In each domain, the number of days in which the person has been doing the activity for at least 10 minutes and the duration of physical activity in terms of day and minutes are asked. The intensity of total physical activity was calculated by means of metabolic equivalence (MET). Each MET represents the amount of energy consumed per minute for one person at rest. Each MTE is equivalent to 3.5 millimeters of oxygen consumed per one kilogram of body weight. If the total energy expended for vigorous physical activity is 1500 MET/min/week in at least 3 days from the last 7 days, or if the total energy expended for a combination of moderate and vigorous physical activity or walking is 3000 MET/min/week, the intensity of physical activity is considered intense. Having intense physical activity for 3 days or more, having 5 days of moderate physical activity, walking for at least 30 minutes a day, or having intense activity with total energy expenditure equaling to 600 MET/week were considered as moderate-intensity physical activity. If there is no physical activity or the activities do not meet the above conditions, they are considered low intensity (15). The IPAQ was developed by an international group in Geneva in 1998. This questionnaire is adapted for the determination of physical activity of adults aged 15-69 and has been used in numerous studies in different countries. The validity and reliability of this questionnaire has been approved in Iran by Baghiani et al (16).
To measure the participants' height and weight, two digital scales (Omron, China made) were used respectively. The weight of the participants was measured as they were barefoot in light clothing. Their height was measured with the Omron stadiometer, while they were standing barefoot. To measure the girth of the waist and hips, a flexible measuring tape was used. The German Bauer diagnostic scale (BG64 USB) was used for measuring body fat percentage. After turning on the device, it was placed on a flat surface and the women were requested to step barefooted. Participants' characteristics, such as age, gender, weight, and level of physical activity were recorded in the device. The percentages of body fat, water, muscle, and bone mass, as well as basal metabolism were measured and recorded. All measurements were done by a trained midwife.
Intervention
The two groups were given instructions to promote their physical activity either through text messaging or mobile social networking. For the social networking group, a Telegram group was set up and all women (n=55) were asked to join this group. Both groups received information about the need for physical activity, the benefits of physical activity, barriers to doing physical activity, and how to overcome these barriers. Women in the text messaging group received text messages involving the same content as that presented to the mobile social networking group three times a week.
The women in two groups were requested to complete IPAQ prior to the intervention, as well as four, eight and twelve weeks after the intervention. Furthermore, anthropometric indices were measured over the aforementioned periods. All women kept journals to record their physical activity. Upon completion of the study, individuals from both groups received payment for their Internet usage (CONSORT checklist, supplementary material 1).
Statistics
Data analysis was performed using SPSS version 23. To compare the quantitative variables in the two groups, the independent t-test was used if the distribution was normal, and if it was not normal, the Mann-Whitney test was used, which was also used for qualitative variables. The Chi-square test was used for nominal or qualitative data. Paired t-test and Wilcoxon test were used for within group comparisons before and after the intervention. To compare the changes in each group in weeks 4, 8, and 12, the repeated measures test was used if the data were normal, and otherwise, the Friedman test was used. The significance level was set at <0.05.