This study investigated the effectiveness of a Healthy Living Awareness Program for the Prevention of Osteoporosis based on the Information-Motivation-Behavioral Skills Model (HLAPPO-IMB) in university students. The study adopted a randomized controlled trial intervention pretest, posttest, and follow-up research design. Participants were randomized into intervention (n=43) and control groups (n=44). Data were collected using a personal information form, the Osteoporosis Knowledge Test, the Osteoporosis Health Belief Scale, the Osteoporosis Self-Effective Scale, and the International Physical Activity Questionnaire Short Form.

The primary outcome measure was the participants' knowledge and health beliefs about osteoporosis. The secondary outcome measure was the participants' healthy lifestyle behavior skills (self-efficacy in weight-bearing exercises, taking calcium, and engaging in physical activity).

Research questions (RQ) RQ1: Does "Healthy Living Awareness Program for the Prevention of Osteoporosis based on the Information-Motivation-Behavioral Skills Model" expand participants' knowledge of osteoporosis? RQ2: Does "Healthy Living Awareness Program for the Prevention of Osteoporosis based on the Information-Motivation-Behavioral Skills Model" enhance participants' health beliefs? RQ3: Does "Healthy Living Awareness Program for the Prevention of Osteoporosis based on the Information-Motivation-Behavioral Skills Model" improve participants' self-efficacy in doing weight-bearing exercises and taking calcium? RQ4: Does "Healthy Living Awareness Program for the Prevention of Osteoporosis based on the Information-Motivation-Behavioral Skills Model" improve participants' self-efficacy in engaging in physical activity?

This study adopted a randomized controlled trial pretest, posttest, and follow-up research design. The study was conducted between March and August 2021 at a public university in Türkiye. The study adhered to the CONSORT (Consolidated Standards of Reporting Trials) guidelines. Participants were randomized into intervention and control groups. Eligible students were randomized to intervention group or control group using block randomization technique. Blinding in the study was not feasible. Blinding could not be performed because the researchers were aware of the interventions and carried out the implementation. The intervention group attended the HLAPPO-IMB, which had three stages: information, motivation, and behavioral skills development. The control group did not undergo the intervention.

The study population consisted of 125 fifth-semester nursing students in the fall term of the 2020-2021 academic year. The undergraduate nursing programs in Türkiye are eight-semester programs. The mean Osteoporosis Knowledge Test (OKT) scores were used to determine the sample size. Power analyses were performed based on the difference between two independent means by G*Power 3.1.9.7. A power analysis was performed to determine the sample size in line with the literature [OKT: experimental group X̅±SD: 18.95±4.98 and control group X̅±SD: 15.18±3.88]. The results showed that a sample of 76 would be large enough to detect significant differences (0.84 effect size, 0.05 level of error, and 95% power). All students who met the inclusion criteria were recruited to avoid missing data. The first sample consisted of 87 participants, who were randomized to intervention (n=43) and control (n=44) groups. However, one student from the intervention group declined to participate. Therefore, the final sample consisted of 86 participants.

The data were collected using a personal information form, the Osteoporosis Knowledge Test (OKT), the Osteoporosis Health Belief Scale (OHSB), the Osteoporosis Self-Effective Scale (OSES), and the International Physical Activity Questionnaire Short Form (IPAQ-SF).

The personal information form: This form was prepared by the researchers. The form consisted of 30 items on sociodemographic characteristics and factors that might affect bone mineral density. Each participant's BMI, body weight, and body height were calculated based on his/her self-report.

Osteoporosis knowledge test: The instrument consists of 24 items. The total score ranges from 0 to 24, with higher scores indicating more osteoporosis-related knowledge.

Osteoporosis health belief scale: The instrument consists of 42 items rated on a Likert-type scale. The total score ranges from 42 to 210, with higher scores indicating more positive health beliefs about osteoporosis.

Osteoporosis self-effective scale: The scale consists of 12 items and two subscales: The Osteoporosis Self-Efficacy Exercise Scale (six items: starting an exercise program, changing exercise habits, doing appropriate exercise, etc.) and the Osteoporosis Self-Efficacy Calcium Scale (six items: increasing calcium intake, choosing calcium-rich foods, maintaining dietary calcium intake, etc.). The total score of each subscale ranges from 0 to 600. The total score ranges from 0 to 1200, with higher scores indicating better self-efficacy in weight-bearing exercises and taking calcium.

International physical activity questionnaire short form: The form consists of seven items on physical activity. The total score is the "Metabolic Equivalent of Task minute/week (MET min/week)." The total score is calculated as "MET min/week" by multiplying the minute, day, and MET values. Physical activity levels are classified as low (<600 MET min/week), moderate (600-3000 MET min/week), or high (>3000 MET min/week) according to the total MET min/week values.

Healthy life diary: The researchers developed the Healthy Life Diary to monitor the intervention group participants' healthy lifestyle behaviors to protect themselves from osteoporosis. The intervention group participants filled out the diary regularly and noted their daily calcium intake, type and duration of exercise, duration and time of sunlight exposure, and amount of tobacco, coffee, tea, cola, etc.

Procedure: The data were collected online because of the COVID-19 pandemic. The researchers briefed students on the research procedure and texted them a link to the survey on WhatsApp. The first page of the survey was a consent form. After obtaining informed consent, the researchers directed all students who agreed to participate to the inclusion criteria section. Students are a vulnerable population. Thus, the researchers took measures to ensure students would not feel coerced to participate. The researchers informed all students about the research purpose and procedure. Participation was voluntary. The researchers kept all personal information confidential. All participants had pseudonyms.

Healthy living awareness program for the prevention of osteoporosis: The intervention group participants underwent the Healthy Living Awareness Program for the Prevention of Osteoporosis (HLAPPO-IMB) in three stages based on IMB.

Information stage: The researchers provided the intervention group participants with online training in healthy living awareness to prevent osteoporosis (400 minutes and two days). They held the training at all participants' convenience outside the class hours. The training consisted of four sections: osteoporosis and diagnosis-treatment methods, current approaches to the prevention of osteoporosis, osteoporosis and nutrition, and osteoporosis and physical exercise. The researchers employed interactive teaching methods and consulted three experts to prepare PowerPoint presentations. At the end of the training, the researchers taught the intervention group participants how to fill out the healthy life diary, such as calculating daily calcium intake. The researchers texted the intervention group participants all training videos on WhatsApp to allow them to watch them again. All participants filled out the OKT and OHSB (posttest) two and three weeks after the training. They filled them out again two months after the posttest (follow-up).

Motivation stage: The researchers regularly texted (WhatsApp) spot and reminder notifications concerning the prevention of osteoporosis. They asked them to assess the health behaviors they recorded in their diaries every week (daily calcium intake, weekly exercise duration, etc.) and the problems they experienced during the process. The researchers provided individual counseling to the participants by telephone (combating smoking, exercise barriers, food exchange for calcium sources, etc.)

Behavior skills stage: The target behavior skills were improved self-efficacy in doing weight-bearing exercises, taking calcium, and engaging in physical activity. The OSES was used to assess participants' self-efficacy to initiate and maintain behavior related to exercise and calcium taking, while the IPAQ-SF was used to assess their physical activity levels.

Data analysis: The data were analyzed using the Statistical Package for Social Sciences. Percentage, mean, and standard deviation were used for descriptive analysis. The categorical variables were analyzed using the Pearson, Fisher χ2, and Marginal Homogeneity tests. The Mann-Whitney U test was used to compare two independent groups. The Wilcoxon Signed Rank test or Friedman nonparametric test was used for dependent measurement comparisons. The effect size (r or Kendall W) was calculated for each comparison. The following limit values were accepted for the interpretation of the effect sizes: r < 0.29 "small effect," r=0.30-0.49 "medium effect," r ≥ 0.50 "large effect." W effect size: <0.39 "small effect," 0.40-0.59 "medium effect,"≥ 0.60 "large effect". The Mann-Whitney U Test was used to compare the difference in age, menarche age, BMI, and scale scores between the groups. The Wilcoxon Signed Rank test was used to compare the pretest and posttest scores. Friedman test was used for repeated measures for dependent groups. Dunn's Bonferroni correction was used to determine the source of the difference.

Inclusion Criteria:

• having received no training on osteoporosis before
• having no disability that prevents physical activity

Exclusion Criteria:

• involuntary

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

Blinding in the study was not feasible. Blinding could not be performed because the researchers were aware of the interventions and carried out the implementation.