Development and psychometric testing of the ‘barriers to physical activity during pregnancy scale’ (BPAPS)

BACKGROUND: Pregnancy can affect the amount of physical activity that women engage in, so ensuring adequate physical activity in pregnant women can be a challenge. Therefore, there is a need to explore and identify barriers to physical activity in this population. Consequently, this study was conducted in order to develop and validate a scale to assess barriers to physical activity in pregnant populations. METHODS: The study was conducted in two phases. During phase 1, a comprehensive review of the most relevant literature from electronic databases on barriers to physical activity was carried out and appropriate scale items were extracted using a deductive approach. During phase 2, the psychometric properties of the extracted scale items were determined using face, content and construct validity, internal consistency and stability. Qualitative and quantitative face validity was assessed via face-to-face interviews with 30 and 10 pregnant women, respectively. To confirm the qualitative and quantitative content validity, 10 experts in the field of research and instrument design were invited to complete the resulting scale. To assess construct validity, the scale items were further tested among 320 pregnant women attending perinatal clinics at health centers in Ilam, Iran, where data were collected via continuous sampling. The internal consistency and stability of the study were measured by Cronbach's alpha and intra-class correlation coefficient (ICC), respectively. RESULTS: Following a review of the relevant literature, 48 items for the BPAPS were extracted. Subsequent to the assessment of face and content validity, the number of items was reduced to 38. Through a subsequent exploratory factor analysis, the number of items dropped further to 29. These items were then structured under four major factors. Finally, the internal consistency and stability of the scale was confirmed by a Cronbach alpha coefficient of 0.824 and a test-retest reliability score of 0.87. CONCLUSION: Findings show that the 29-item scale to assess barriers to physical activity in pregnant populations is a valid and appropriate instrument.