Measure of Time Toxicity
toxicity, toxicities
EVENTS, INFUSION REACTION
As previously described, we considered any day with physical health care system contact as a time toxic day.We calculated patient-level time toxicity (days with physical health care system contact) by analyzing treatment and follow-up forms and resource utilization assessment forms. The treatment and follow-up forms listed the dates of protocol-related health care contact (eg, bloodwork, infusions, imaging studies, etc). The resource utilization assessment form was completed every 28 days for each participant by trial staff, with the aim of collecting data on the number and type of medical resources consumed by each patient. The forms collected non–protocol-related office/clinic visits, outpatient procedures/treatments (such as imaging, transfusions, paracentesis, radiation, and chemotherapy), emergency department visits, hospitalizations, and admission to a facility (rehabilitation, long-term care, hospice, and others), along with the dates of each contact. If the exact date of an outpatient encounter was not recorded, we considered it to be on a separate day. The date(s) of an inpatient encounter (in hospital) were always available. For a time toxic day, we further classified the source of time toxicity as (1) planned and (2) unplanned, depending on if it was related to a per-protocol visit or an additional visit. If a day had both planned and unplanned time toxicities (eg, planned cetuximab leading to an infusion reaction leading to an emergency department visit), we treated it like planned time toxicity since it occurred first and was independent of future events.A day without physical health care contact was considered a home day. Thus, a day could either be a time toxic day or a home day. For an individual patient, OS was the sum of time toxic days and home days. The resource utilization assessment forms also collected visits by clinicians to patients' homes and procedures (eg, scans and thoracenteses) performed when a patient was inpatient. We excluded these visits from time toxicity analyses since they either did not require patient travel to a health care facility or the inpatient day was already included as a time toxic day.