Understanding of how to analyze and interpret quality of life (QoL) data from clinical trials in patients with advanced gastrointestinal cancer is limited.
In order to look at this problem, researchers from Uppsala, Sweden, investigated alternative methods of interpreting QoL data in advanced gastrointestinal cancer patients.
The team reanalyzed data from 2 randomized trials, which compared chemotherapy and best supportive care with best supportive care alone. A total of 113 patients with pancreatic, biliary, or gastric cancer were included in these.
Patient benefit was evaluated by the treating physician (subjective response), and by using selected scales and different summary measures of the EORTC QLQ-C30 questionnaire.
| Summary QoL measures could discriminate between treatment regimens.
| British Journal of Cancer |
An increasing number of dropouts (mainly due to death) with time were found not to occur in a random fashion. Therefore, the mean scores in the different subscales of the QLQ-C30, obtained during the follow-up of interviewed patients, did not reflect the outcome of the randomized population.
The scores of the patient-provided summary measure, 'Global health status/QoL', were stable in a rather high proportion of the patients, and could not discriminate between the 2 groups.
The researchers found that 3 other summary measures revealed greater variability. They all discriminated between the 2 groups.
A high agreement was also seen between the changes in the summary measures and the subjective response.
Author K. Nordin, of Uppsala University, concluded on behalf of the group, "A categorization of whether an individual patient has benefited or not from the intervention could overcome the problem with selective attrition."