To the Editor: Dr Zimmermann and colleagues1 concluded that there is scant evidence to support the effectiveness of specialized palliative care. There are at least 3 reasons to question the study's methods and findings.
First, of the 22 selected trials, 1 did not include non–palliative care controls (reference 28 in the original article), 9 trials (references 30, 31, 33, 36, 39, 42, 43, 46, and 48 in the original article) did not involve interventions that met currently accepted definitions of palliative care services,2 and 3 were conducted more than 20 years ago (references 47, 48, and 49 in the original article). Second, a key outcome in this review was quality of life, using measures heavily influenced by physical function. Function is expected to decline in the setting of advanced illness. Function-based quality-of-life measures are not relevant in assessing palliative care's impact.3 Third, the review is limited to randomized controlled trials (RCTs) and excludes well-designed quasi-experimental/observational studies.