Instead of testing how well a particular intervention treats a disease or its symptoms, a trial focused on quality of life assesses how much a person can continue to do and enjoy their typical everyday activities without substantial pain, hardship, emotional disturbance or other negative effects from the treatment. These trials are particularly important with chronic conditions and in oncology because their results provide useful information to providers and patients in making decisions about what therapies to try and what the risk-benefit trade-off might be. Increasingly, quality of life has become a common secondary endpoint in many trials, but trials focused primarily on quality of life as a primary endpoint remain important.
