Abstract
Purpose: The main purpose of this paper is to present the results of a randomized trial comparing the effects of two chemotherapy regimens on the Quality of life (QOL) of patients with advanced non-small-cell lung cancer (NSCLC). Trials in advanced stage disease represent an important treatment context for QOL assessment. A second purpose of this paper is to examine methods for handling the level of missing data commonly observed in the advanced stage disease context. Methods: Patients were randomized to receive cisplatin plus vinorelbine or carboplatin plus paclitaxel. The QOL of 222 patients was assessed with the Functional Assessment of Cancer Therapy - Lung (FACT-L) prior to randomization; follow-up assessments occurred at 13 and 25 weeks. Three methods were used to analyze the QOL data: (1) cross-sectional analysis of four patient categories (improved, stable, missing, and declined) based on changes in the FACT-L score, (2) a mixed linear model, and (3) a pattern mixture model. The longitudinal analyses addressed two potential data biases. Results: Questionnaire submission rates were 91% at baseline, 68% at 13 weeks, and 47% at 25 weeks. The cross-sectional and mixed linear model analyses did not show significant differences by treatment arm in patient-reported QOL. The pattern mixture model analysis, more appropriate given non-ignorable missing data, also found no statistically significant effect of treatment on patient QOL. Conclusion: We present a sensitivity analysis approach with multiple methods for analyzing treatment effects on patient QOL in the presence of substantial, non-ignorable missing data in an advanced stage disease clinical trial. We conclude that the two treatment arms did not differ statistically in their effects on patient QOL over a 25-week treatment period.
Original language | English (US) |
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Pages (from-to) | 115-126 |
Number of pages | 12 |
Journal | Quality of Life Research |
Volume | 11 |
Issue number | 2 |
DOIs | |
State | Published - 2002 |
Keywords
- FACT-L
- Non-small-cell lung cancer
- Quality of life
- Randomized trial
ASJC Scopus subject areas
- Rehabilitation
- Nursing(all)