The Transplant Effects Questionnaire (TxEQ): The development of a questionnaire for assessing the multidimensional outcome of organ transplantation - example of end stage renal disease (ESRD)

Br J Health Psychol. 2002 Nov;7(Part 4):393-408. doi: 10.1348/135910702320645381.

Abstract

OBJECTIVES: To develop a questionnaire to assess the responses of transplant recipients to the receipt of an organ, including their self-care behaviour. DESIGN: Following a literature review, open-ended interviews and a focus group, a transplant questionnaire was developed. Two studies (Study 1: N = 231, Study 2: N = 105) were conducted to evaluate its psychometric properties. METHODS: A pool of 51 items was derived from themes identified in published studies and from interviews and a focus group discussion with renal transplant recipients. These were constructed into a questionnaire and were then administered to two renal transplant out-patients populations. Item responses of study sample 1 were subjected to principal components analysis (PCA) using varimax rotation to examine the structure of responses. In order to investigate the stability of the factor structure found in Study 1, item responses of the second sample were subjected to confirmatory factor analysis (CFA) using structural equation modelling. RESULTS: PCA indicated six factors that accounted for 64.2% of the variance. With extraneous items omitted, the final questionnaire derived from Study 1 has 24 items clustered around five conceptual coherent factors: worry about transplant (22.1%), guilt regarding donor (11.9%), disclosure (9.58%), medication adherence (8.73%), and responsibility (6.63%). CFA on the final 24-item version of the TxEQ revealed that the resulting model was a good fit for the Study 2 data (RMSEA = 0.08, pclose =.005). CONCLUSIONS: The TxEQ has potential application as a measure in the area of transplantation research. CFA demonstrated that the factor structure of the TxEQ is consistent across different renal transplant out-patients populations. Further research is currently in progress to assess other groups of transplant recipients and to examine its relationship to other measures.