Validation of the LPA-SQUASH in post-liver-transplant patients

This study aimed to validate the revised Short Questionnaire to Assess Health-Enhancing Physical Activity (SQUASH) to measure sedentary activity in post-liver-transplant patients. The proposed scale could be useful for transplantation nurses to assess and modify sedentary lifestyles and increase physical activity. The SQUASH was modified to include items on sitting time and light-intensity physical activity (LPA-SQUASH). A pilot study was conducted with 20 liver transplant patients, and an expert panel validated the scale contents. Then, post-liver-transplant outpatients at a Japanese university hospital participated in the main study (September-October 2020), in which questionnaires were mailed twice to assess test-retest reliability, and accelerometers used to establish criterion validity. Intra-class correlation coefficients (ICC) were calculated for test-retest reliability. Spearman correlations and Bland-Altman plots were used to assess validity and measurement error. In total, 173 participants returned the questionnaires, and 106 and 71 completed the reliability and validation studies, respectively. The range of LPA-SQUASH correlation coefficients for test-retest was .49-.58. ICCs ranged from .72 to .80 for items other than leisure. Accelerometer data and the LPA-SQUASH total physical activity amount and light-intensity physical activity correlated moderately. We modified the SQUASH, which was developed to measure physical activity in healthy adults, to assess light-intensity physical activity in post-liver-transplant patients. The LPA-SQUASH showed acceptable validity and reliability. The questionnaire may be used by transplantation nurses to examine light-intensity physical activity content/duration, deliver patient education considering patients' sedentary lifestyle, and facilitate goal setting for physical activity interventions to prevent metabolic syndrome.