Background: Previous work highlighted a number of methodological constraints when reporting health-related quality of life (HRQOL) outcomes from randomized controlled trials (RCTs). Given this, the objective of this study was to investigate whether the quality of such HRQOL reports has improved over time.
Materials and methods: On the basis of a predefined set of criteria, 159 RCTs with a HRQOL end point, published between 1990 and 2004 were identified and analyzed. Each study was evaluated by a number of issues (e.g. sample size and industry sponsorship) and by the "minimum standard checklist for evaluating HRQOL outcomes in cancer clinical trials".
Results: The quality of HRQOL reports, as measured by the overall checklist score, was independently related to more recently published studies (P < 0.0001). This relationship was independent of industry funded, HRQOL end point (primary versus secondary), cancer disease site, size of the study and HRQOL difference between treatment arms. While only 39.3% of studies published between 1990 and 2000 (89/159 RCTs) were identified as being probably robust, thus likely to support clinical decision making, this percentage was 64.3% for studies published after 2000 (70/159 RCTs).
Conclusion: Since we found a significant learning curve in HRQOL trial reporting since 1990, it can be expected that HRQOL data will increasingly impact on clinical decision making and treatment policies in the near future.