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 ≥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.