Instruments
1. The manual of the physical activity promotion program
The manual of the physical activity promotion program was developed, by the primary researcher, based on Pender’s HPM and self-efficacy theory. The program consisted of the provision of knowledge, discussion of participants’ experiences, modeling, increasing social support from peers, promoting enjoyment and motivation, and practice of aerobic dances via video compact disks (VCDs) and a research assistant, with the use of goal setting and self-monitoring.
2. Instruments for data collection
2.1 Personal Data Sheet: A researcher designed questionnaire was used to collect demographic and socioeconomic data of the participants, such as body weight, height and family income.
2.2 The Perceived Self-efficacy to Physical Activity Questionnaire (PSEPAQ): The PSEPAQ was modified from the Perceived Self-efficacy to Physical Activity Scale questionnaire,18 and was translated into Thai by Deenan.19 The PSEPAQ was a unidimensional instrument composed of 14 items. Participants were required to rate each of the items with the responses ranging from ‘not at all confident’ (0%) to ‘very confident’ (100%). Internal consistency reliability of the PSEPAQ was .89 and .90 when applied with 311 bilingual Thai high school students for the English and Thai versions.19
2.3 The Physical Activity Questionnaire (PAQ): The PAQ for Thai children was developed by Kijboonchoo and colleagues.28 The questionnaire assessed how often participants performed physical activity within the past seven days, number of minutes that participants had sedentary behavior (i.e. watching TV), exercising, playing sports, doing housework and having transportation physical activity. Sedentary behavior and transportation physical activity were calculated to describe the characteristics of the participants who recorded each item of physical activity. Validation of secondary school children questionnaire was 0.260, while the cross-validation was 0.33. Results also showed the intra-class correlation for test-retest repeatability was 0.74.28
2.4 Physical fitness test: A battery of simple field tests was used. There were four fitness assessments, including: sit-ups, push-ups, sit-and-reach, and run.26 Sit-ups and push-ups were recorded in terms of the number of times (repetitions) in 30 seconds. Sit-and-reach was recorded twice and the further reach (cm.) was used. Run was tested by the time it took to run, or walk, 800 meters. Outcomes were recorded in minutes and seconds.
These instruments were tested to ensure their reliability with 30 Thai adolescent girls whose characteristics were similar to those of the participants. Cronbach’s alpha coefficient of PSEPAQ and PAQ were 0.86 and 0.74. Inter-rater reliability by two observers of sit-ups was 1.0, while that of push-ups was 0.997, and of test-retest of sit-and-reach was 0.971. Mean score of the run was 4.95 minutes.