Table A1.

Descriptions of the Outcome Categories.

Outcome Categories	Descriptions
Quality of life	Long-term maintenance of quality of life and functional status. Also includes other patient reported/centered measurements such as keeping one’s independence and social/role functioning. E.g., quality of life, maintaining independence of (instrumental) activities of daily living (iADL), worries, anxiety
Transient short-term side effects	Short-term and transient treatment-related toxicity/adverse events that terminate after cessation of treatment or that only require minimal medication. E.g., diarrhea, hair loss, nausea/vomiting, rash and skin change
Severe and persistent side effects	More severe adverse treatment events that require intensive treatment, hospitalization or discontinuation of treatment. Often patients will recover from these events, but it can take a long time (>6 months) and involves intensive treatment. Persistent side effects/sequelae inherent or caused by the treatment are also included here. E.g., severe bleeding, gastrointestinal perforation, heart attack, colostomy, neuropathy, fatigue, scars, permanent fecal incontinence, urinary incontinence, infertility
Treatment response	All treatment benefits, except for time-dependant measurements. Treatment benefits other than survival, like symptom reduction, response seen on scans, or risk reductions. E.g., symptom control, local control, complete response, partial response, recurrence risk
Progression- and disease-free survival	Progression-free survival or disease-free survival, but not overall survival. A time-dependent measurement that indicates how long the disease is under control or cured. Also a measurement of efficacy, but time-dependent. E.g., disease-free survival, progression-free survival, time to treatment failure
Overall survival	Overall survival and mortality independent of the cancer (treatment) at a certain time point during follow-up. E.g., overall survival, mortality at a certain time point, extending life