A pooled analysis of quality of life measures and adverse events data in north central cancer treatment group lung cancer clinical trials

BACKGROUND: In this pooled analysis, the authors examined correlations between single-item and multiple-item quality of life (QOL) measures and assessed the agreement between clinically significant changes in QOL and patient-reported adverse events (AE). METHODS: Data from 6 lung cancer clinical trials that involved 358 patients were pooled. All trials incorporated the Uniscale and 1 of 3 multiple-item assessments: the Functional Assessment for Cancer Therapy-Lung, the Lung Cancer Symptom Scale, or the Symptom Distress Scale. Spearman rank correlations and a Bland-Altman approach were used to assess agreement. Time-to-event analysis was performed using the Kaplan-Meier method. RESULTS: Correlations between the Uniscale and multiple-item assessments were substantial (correlation coefficient = 0.49-0.66). At least 1 10-point decline was reported in the Uniscale and multiple-item assessments by 58% of patients and 39% of patients, respectively. At least 1 severe AE (grade >or=3) was reported in 35% of patients postbaseline. The percent agreement between experiencing a severe AE and a decline in QOL was 48% and 59% for the Uniscale and multiple-item assessments, respectively. The median time to the first 10-point decline in QOL for the Uniscale and multiple-item assessments was 67 days and 142 days, respectively, and the median time to the first occurrence of a severe AE was 304 days. CONCLUSIONS: Information gleaned from the single-item Uniscale assessment was comparable to that gleaned from multiple-item global measures. There was moderate agreement between QOL and AE. A 10-point decline in QOL occurred earlier than Common Toxicity Criteria AE reporting. This suggests the need for inclusion of a QOL instrument in lung cancer clinical trials.