The impact of symptoms and comorbidity on health utility scores and health-related quality of life in small cell lung cancer using real world data.

PURPOSE Small cell lung cancer (SCLC) is a highly fatal disease associated with significant morbidity, with a need for real-world symptom and health utility score (HUS) data. HUS can be measured using an EQ-5D-5L questionnaire, however most captured data is available in non-SCLC (NSCLC) only. As new treatment regimens become available in SCLC it becomes important to understand factors which influence health-related quality of life and health utility. METHODS A prospective observational cohort study (2012-2017) of ambulatory histologically confirmed SCLC evaluated patient-reported EQ-5D-5L-derived HUS, toxicity and symptoms. A set of NSCLC patients was used to compare differential factors affecting HUS. Clinical and demographic factors were evaluated for differential interactions between lung cancer types. Comorbidity scores were documented for each patient. RESULTS In 75 SCLC and 150 NSCLC patients, those with SCLC had lower mean HUS ((SCLC vs NSCLC: mean 0.69 vs 0.79); (p < 0.001)) when clinically stable and with progressive disease: ((SCLC mean HUS = 0.60 vs NSCLC mean HUS = 0.77), (p = 0.04)). SCLC patients also had higher comorbidity scores ((1.11 vs 0.73); (p < 0.015)). In multivariable analyses, increased symptom severity and comorbidity scores decreased HUS in both SCLC and NSCLC (p < 0.001); however, only comorbidity scores differentially affected HUS (p < 0.0001), with a greater reduction of HUS adjusted per unit of comorbidity in SCLC. CONCLUSION Patients with advanced SCLC had significantly lower HUS than NSCLC. Both patient cohorts are impacted by symptoms and comorbidity, however, comorbidity had a greater negative effect in SCLC patients.