Does it matter how we evaluate HRQOL? Longitudinal comparison of the EORTC QLQ-C30/QLQ-OG25 and FACT-E.

Abstract

To determine whether EORTC QLQ-C30/QLQ-OG25 and FACT-E compared longitudinally provide similar reflections of health-related quality of life (HRQOL). Eighty-six esophageal cancer patients treated with curative intent, scheduled to complete both questionnaires at baseline and post-treatment time points until 36months. A generalized estimating equation model utilizing a Gaussian family compared instruments longitudinally. The two-one-sided-test (TOST) method assessed equivalence between the instruments. Trajectories for social domain and overall quality of life differed significantly between instruments. Also, FACT-G's functional well-being post-treatment returns to baseline 3-6months earlier than the EORTC QLQ-C30's role functioning subscale, suggesting measurement of different components. Trajectories for physical and esophageal symptom subscales are similar and are deemed equivalent. Emotional domains are comparable and bear little resemblance to the physical domain trajectories indicating reflection of emotional experience rather than a physical proxy. EORTC QLQ-C30 subscales have a trajectory similar to its physical functioning scale except for the emotional and esophageal symptoms scales. Overall HRQOL in both instruments showed a consistent return to baseline/pre-treatment levels by 6months post-treatment. Overall HRQOL recovers earlier after curative-intent treatment than previously reported despite persistence of physical symptoms, with a consistent return to pre-treatment levels by 6months after treatment. This supports the concept that HRQOL is not primarily defined by physical function. Based on this longitudinal comparison, FACT-E provides a more multidimensional assessment of HRQOL. Curative intent treatment for esophageal cancer has adverse effects on HRQOL but despite intense treatment, overall HRQOL recovers within 6months.