Patient and author diversity and representation in studies supporting the European Respiratory Society/European Society of Intensive Care Medicine/European Society of Clinical Microbiology and Infectious Diseases/Asociación Latinoamericana de Tórax severe community-acquired pneumonia guidelines.

Objective: Insufficient diversity is common among patients and authors in studies supporting guidelines. We hypothesized that the latest severe community-acquired pneumonia (CAP) guidelines suffered from such bias. Methods: We reviewed all original studies supporting the latest severe CAP guidelines. We assessed whether there were language restrictions in the search for studies to be included in each recommendation and recorded the following: the proportion of female patients included in the studies; ethnicity (when available); year of publication; and study location, which was classified by income in accordance with the World Bank classification. We also compiled data on the sex and affiliation of the first and last authors. Results: The guidelines included 115 references in eight sections; 74 unique references supported the recommendations. There was language restriction in the selection of studies in 3 of 8 questions. The proportion of female patients ranged from 4.7% to 70.5% (mean, 36%). Most of the patients were White (72.2-91.2%), and 80.5% of the studies were conducted in high-income countries. Only 6 (5.2%) of the 115 references included patients from low- or middle-income countries. Most of the first and last authors were male (75.6-88.3%) and were based in high-income countries (96.1%). Conclusions: The studies supporting the severe CAP guidelines were found to have insufficient diversity and representativeness of patients, sex, and country of origin of the authors. To enhance the generalizability of severe CAP guidelines, strategies must be devised to increase the diversity of patients and authors.