The Validity of Patient-Reported Outcome Measures of Quality of Life in Palliative Care: A Systematic Review

Importance: A recent systematic review and meta-analysis found that palliative care was not associated with improvement in quality of life (QOL) in terminal noncancer illness. Among potential reasons for a null effect, it is unclear if patient-reported outcome measures (PROMs) measuring QOL were derived or validated among populations with advanced life-limiting illness (ALLI). Objective: To systematically review the derivation and validation of QOL PROMs from a recent meta-analysis of randomized controlled trials (RCT) of palliative care interventions in people with terminal noncancer illness. Evidence Review: EMBASE, MEDLINE, and PsycINFO were searched from inception to January 8, 2023 for primary validation studies of QOL PROMs in populations with ALLI, defined as adults with a progressive terminal condition and an estimated median survival of less than or equal to one year. The primary outcome was the proportion of PROMs that were derived or validated in ≥1 ALLI population. Findings: Twenty-one unique studies of derivation (n = 13) and validation (n = 11, 3 studies evaluated both) provided data on 9657 participants (mean age 63 years, 50% female) across 15 unique QOL PROMs and subscales. Among studies of validation, 9 were in people with cancer (n = 2289, n = 5 PROMs), 1 in neurodegenerative disease (n = 23, n = 1 PROM), and 1 with mixed diseases (n = 248, n = 1 PROM). Across 15 QOL PROMs and subscales, 47% (n = 7) were derived or validated in an ALLI population. The majority of these seven PROMs were exclusively derived or validated among people with cancer (57%, n = 4). QOL PROMs such as Quality of Life at End of Life, EuroQoL-5 Dimension 5-level, and 36-item Short Form Survey demonstrated validity in more than one terminal noncancer illness. Conclusions: Most QOL PROMs that measured the effect of palliative care on QOL in RCTs were neither derived nor validated in an ALLI population. These findings raise questions about the inferences that palliative care does not improve QOL among people with terminal noncancer illness.