A scientific review published today: NEJM Evidence JournalThe study, coordinated by the Dole Institute for Research and Education (IDOR), evaluated outcomes in adults with community-acquired pneumonia (CAP) admitted to intensive care units (ICUs) in middle-income countries.
In contrast to high-income countries, where mortality rates range from 16% to 26%, the study found that mortality rates were significantly higher in the countries analyzed. The study recruited 52 studies and approximately 48,707 patients and found an overall mortality rate of 37.1%, increasing to 59.3% for patients requiring respiratory support.
Severe pneumonia remains an underdiagnosed problem
Community-acquired pneumonia (CAP) remains one of the leading causes of ICU admission in low- and middle-income countries, with mortality rates significantly higher than those observed in high-income countries, and outcomes consistently favorable.
Despite advances in clinical management and intensive care support, this study showed that outcomes remain poor even after 20 years in non-rich countries, particularly in settings with structural limitations. The authors emphasize that the observed high mortality rates cannot be explained solely by the individual severity of the disease among patients, but also by systematic differences in access and quality of care.
This study is important because the data confirms the lack of consistent, structured information on severe community-acquired pneumonia in ICUs in low- and middle-income countries. Despite being the leading cause of ICU admissions worldwide, severe community-acquired pneumonia continues to have a high mortality rate. ”
Dr. Melissa Pitrovsky, lead author of the study, physician at Copador Hospital and researcher at the Federal University of Rio de Janeiro (UFRJ)
How to conduct research
This study followed rigorous international scientific quality standards and was registered in PROSPERO, the world’s leading database of systematic review protocols.
The studies included in the analysis were published over a 22-year period from 2002 to 2024 and also underwent methodological quality assessment. Fifty-two studies involving a total of 48,707 patients were analyzed, focusing on low- and middle-income countries and short-term mortality during ICU admission or within 30 days.
High mortality rate and the role of ventilators
This result strengthens the contrast between health systems. The overall mortality rate in the middle-income countries analyzed was 37.1%, far exceeding the mortality rate observed in high-income countries, where outcomes for the disease typically range from 16% to 26%. This difference is even more pronounced in severe cases.
The mortality rate for patients requiring mechanical ventilation reached 59.3% in the analyzed countries, almost double the mortality rate observed in high-income countries (about 26%). These findings confirm that respiratory support, although essential, has less favorable outcomes when provided in settings with limited ICU resources and infrastructure.
The average age of the study subjects was 65.4 years, and men accounted for 60.8% of the participants. The most common comorbidities were hypertension (38.7% of cases), chronic obstructive pulmonary disease (26.2%), and diabetes (20.9%).
The authors also highlight that older age and mechanical ventilation explain more than half of the variation in mortality across studies and are the main clinical determinants of prognosis across countries, but their effects are amplified in low-income settings.
Global inequality and the huge digital divide
One of the most relevant findings of this study is the uneven distribution of available data. The analysis included studies from 18 countries, primarily 25 studies from China, six studies from Brazil, and studies from other middle-income countries.
Studies from low-income countries do not meet applicable methodological quality standards, and this lack of research highlights significant gaps in global scientific output on pneumonia in intensive care and will limit a complete understanding of the disease burden in more vulnerable settings.
Mortality gradients across health systems
The body of evidence shows a consistent pattern of worsening outcomes for community-acquired pneumonia in the ICU as the income level of the health care system declines. Mortality rates remain high in low- and middle-income countries, especially among older people and patients requiring mechanical ventilation, whereas outcomes in high-income countries are significantly better.
The authors attribute these disparities to structural factors such as delays in access to care, delays in patient arrival at intensive care services, limited resources, lack of trained medical teams, and lack of standardized clinical protocols.
Given the well-established importance of vaccination in preventing community-acquired pneumonia (CAP) and improving outcomes, the lack of systematic data on vaccination and prevention in the reviewed studies further exacerbates this problem.
The authors, who are also part of IDOR’s Intensive Care Medicine Research Group, concluded that “further research is needed to adapt health policy, resource allocation, staff training, and protocols to local realities.”
The review’s findings reinforce the need to strengthen health systems, expand early access to intensive care, and generate more representative data across all regions of the world.
sauce:
Doll Research and Education Research Institute
Reference magazines:
Pitrovsky, M. and others. (2026). Outcomes of pneumonia in ICUs in low- and middle-income countries—a systematic review. NEJM records. DOI: 10.1056/EVIDoa2500244. https://evidence.nejm.org/doi/10.1056/EVIDoa2500244
