Use of Quality of Life in Cardiovascular Surgery in Coronary Artery Bypass Grafting: Validation, Reproducibility, and Quality of Life in One Year of Follow-Up

Abstract

Background: The objectives of this study are to validate the Quality of Life in Cardiovascular Surgery (QLCS) questionnaire and to observe the evolution of quality of life in the first year of postoperative follow-up of patients who underwent coronary artery bypass grafting (CABG).

Methods: This was a prospective observational study of patients undergoing CABG from July 2016 to June 2017 who survived and answered the QLCS with 1, 6, and 12 months of follow-up. Validation was evaluated for internal consistency by Cronbach's alpha, test-retest reproducibility by correlation coefficient of concordance, and accuracy for interrater reliability by the kappa statistic. The nonparametric analysis of variance test was used for analysis of repeated measures, during follow-up, of the QLCS was considered significant at p < 0.05.

Results: Included were 360 patients, with a mean age of 63 years; 72% were men. Cronbach's alpha was 0.82, demonstrating adequate internal consistency. The correlation coefficient of concordance was 0.93 and accuracy 0.99, showing good precision and accuracy. The kappa statistic for questions ranged from 0.58 to 0.78, which ensures a moderate reproducibility. Scores of the QLCS in patients undergoing CABG of 17.69, 18.82, and 19.52 were found at 1, 6, and 12 months, respectively. Thus there was a progressive improvement in quality of life over the first year of follow-up (p < 0.0001).

Conclusions: The QLCS proved to be a good questionnaire in this population, with adequate internal consistency and moderate reproducibility. Its use revealed a progressive and significant improvement in the quality of life of patients undergoing CABG.