The Likert scale is a powerful tool for quality of life assessment among patients after minimally invasive coronary surgery

INTRODUCTION: Health-related quality of life (QoL) is an acknowledged index of treatment effectiveness. There are several methods of its evaluation which are predisposed to different risk of bias. AIM: To investigate the agreement between objective and subjective tools of QoL assessment in patients who underwent endoscopic atraumatic coronary artery bypass (EACAB) grafting. MATERIAL AND METHODS: This prospective observational study covered 705 consecutive patients who underwent EACAB between April 1998 and December 2010. Quality of life was assessed in a follow-up of 2132 ±1313 days among 482 subjects using the WHOQoL-BREF questionnaire as an objective tool and the Likert scale as a more subjective method. RESULTS: There was good agreement between a 5-step Likert scale and a 5-step BREF Q1 (‘overall quality of life’) and Q2 (‘general health’) with a concordance correlation coefficient of CCC = 0.64 (95% CI: 0.58–0.69) and CCC = 0.49 (95% CI: 0.43–0.55), respectively. There was also a statistically significant correlation between answers reported using the Likert scale and all domains of BREF: physical health (R = 0.54, p < 0.001), psychological health (R = 0.56, p < 0.001), social relationships (R = 0.45, p < 0.001) and environment (R = 0.56, p < 0.001). CONCLUSIONS: The Likert scale is useful in QoL assessment in patients after minimally invasive coronary surgery. This simple and easy-to-use screening method may be used interchangeably with a more reliable but also more complex questionnaire tool.