Clinical trials of pneumonia management assess heterogeneous outcomes and measurement instruments

Abstract

Objectives: To inform clinical practice guidelines, randomized controlled trials (RCTs) of the management of pneumonia need to address the outcomes that are most important to patients and health professionals using consistent instruments, to enable results to be compared, contrasted, and combined as appropriate. This systematic review describes the outcomes reported in clinical trials of pneumonia management and the instruments used to measure these outcomes.

Study design and setting: Based on a prospective protocol, we searched MEDLINE/PubMed, Cochrane CENTRAL and clinical trial registries for ongoing or completed clinical trials evaluating pneumonia management in adults in any clinical setting. We grouped reported outcomes thematically and classified them following the COMET Initiative's taxonomy. We describe instruments used for assessing each outcome.

Results: We found 280 eligible RCTs of which 115 (41.1%) enrolled critically ill patients and 165 (58.9%) predominantly noncritically ill patients. We identified 43 distinct outcomes and 108 measurement instruments, excluding nonvalidated scores and questionnaires. Almost all trials reported clinical/physiological outcomes (97.5%). Safety (63.2%), mortality (56.4%), resource use (48.6%) and life impact (11.8%) outcomes were less frequently addressed. The most frequently reported outcomes were treatment success (60.7%), mortality (56.4%) and adverse events (41.1%). There was significant variation in the selection of measurement instruments, with approximately two-thirds used in less than 10 of the 280 RCTs. None of the patient-reported outcomes were used in 10 or more RCTs.

Conclusion: This review reveals significant variation in outcomes and measurement instruments reported in clinical trials of pneumonia management. Outcomes that are important to patients and health professionals are often omitted. Our findings support the need for a rigorous core outcome set, such as that being developed by the European Respiratory Society.

Keywords: Clinical trials; Community-acquired pneumonia; Core outcome set; End points; Evidence-based medicine; Hospital-acquired pneumonia; Outcomes; Pneumonia; Systematic reviews; Ventilator-associated pneumonia.