Validity and Reliability of the Malay Versions of Bloating Severity (BSQ-M) and Quality of Life (BLQoL-M) Questionnaires

Abstract

Abdominal bloating (AB) is a prevalent and bothersome symptom, but there are no specific measures for severity and quality of life (QoL) other than the Bloating Severity Questionnaire (BSQ) and Bloating Quality of Life (BLQoL). We aimed to translate the BSQ and BLQoL into the Malay language and to validate them using exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) approaches. The 12-item BSQ has two components, seven-item severity in general (SevGen) and five-item severity in the past 24 h (Sev24), and BLQOL has five items. Translation to the Malay language (BSQ-M and BLQoL-M) was performed using standard forward and backward processes. EFA followed by CFA were performed in participants with AB due to functional bowel disorders, with the purpose of examining the validity and reliability of the questionnaires translated into Malay. After EFA with 152 participants, all the items of BSQ-M remained in the model. Total variance extracted was 53.26% for BSQ-M and 58.79% for BLQoL-M. The internal consistency based on Cronbach’s alpha values was 0.52 for SevGen, 0.86 for Sev24, and 0.81 for BLQoL-M. After performing CFA with another 323 participants, the final measurement model for BSQ-M and BLQoL-M fit the data well in terms of several fit indices (BSQ-M: root mean square error of approximation (RMSEA) = 0.050, Comparative Fit Index (CFI) = 0.966, Tucker–Lewis Fit Index (TLI) = 0.956, and standardized root mean squared residual (SRMR) = 0.051; BLQoL-M: RMSEA = 0.071, CFI = 0.985, TLI = 0.962, SRMR = 0.021). The composite reliability for BSQ-M and BLQoL-M were satisfactory (SevGen = 0.83, Sev24 = 0.89, BLQoL = 0.80). The intraclass correlation (ICC) results showed excellent stability for BSQ-M and BLQoL-M, ranging from 0.74 to 0.93. The Malay language versions of BSQ-M and BLQoL-M are valid and reliable instruments for measuring the severity and QoL of AB for the Asian population with functional bowel disorders.