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

Abstract

Aim: 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.

Methods: 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.

Results: 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.

Conclusion: 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.

Keywords: liver transplantation; metabolic syndrome; patient-reported outcome measures; physical activity; sedentary behavior.