Inclusion criteria, exclusion criteria and study summary
Cancer diagnosis/treatment results in unwanted symptoms/toxicity so assessing the risks and benefits of new treatments requires knowledge of both effectiveness against the cancer and impact on quality of life. Several research groups, including the EORTC, have developed questionnaires to measure quality of life so that patients can be monitored and their treatment side effects investigated. These groups are now looking to enhance the use of their questionnaires more efficiently. It would be helpful to pool results from studies using different questionnaires investigating the same symptoms, but because the questions on each questionnaire are subtly different, this is not easy. In this study patients complete several widely used similar questionnaires. Their scores are then compared with those from the EORTC questionnaires. Using statistical analysis we will produce an algorithm (mathematical equation) 'converting' scores between questionnaires. The algorithm could be useful in clinical research when two groups of researchers are investigating a new drug with a side effect of fatigue but are using different questionnaires to assess this e.g EORTC Fatigue Scale versus FACT Fatigue Scale. The algorithm will link the scores by ‘predicting’ the score on one questionnaire using the score on the other. The two studies can then be compared, or their results pooled, giving a larger sample for analysing any effect. Using other statistics we will compare all the questionnaires and see how good (or not) they are at detecting symptoms (validity and reliability) and how sensitive they are to changes over time as the symptoms worsen or improve . Knowing which are the most sensitive questionnaires for different domains of quality of life and side effects is critical because fewer patients would then need to be recruited in future research.