Table 4_Carbapenem-based versus non-carbapenem therapy for hospital-acquired and ventilator-associated pneumonia in a resource-limited setting: a retrospective cohort study of clinical outcomes.docx

The most common pathogens were Acinetobacter spp. (HAP: 11.3%; VAP: 19.4%) and Pseudomonas aeruginosa (HAP: 11.3%; VAP: 16.1%). The most prevalent comorbidity in HAP was diabetes mellitus (38.7%).

Carbapenem-based therapy (meropenem) was used in 65.6% of cases and the most frequently prescribed non-carbapenem agents were piperacillin-tazobactam, ceftazidime, and colistin. No significant difference in mortality was observed between carbapenem and non-carbapenem therapy in HAP (31.6% vs. 29.2%; RR 1.08, 95% CI 0.50–2.36, p = 0.840) or VAP (65.2% vs. 50.0%; RR 1.30, 95% CI 0.61–2.77, p = 0.440). VAP was associated with significantly higher crude mortality than HAP (61.3% vs. 30.6%; p = 0.005).

Crude mortality rates appeared highest among patients in the Acinetobacter baumannii group (70.4%) and Pseudomonas aeruginosa group (31.3%), though treatment group difference were not statistically significant.</p>Conclusion<p>In this single-center retrospective cohort, no statistically significant association between carbapenem-based therapy and all-cause in-hospital mortality was detected in HAP or VAP. Crude mortality appeared highest among patients with Acinetobacter and Pseudomonas isolates.

However, wide confidence intervals, treatment-selection bias, and unadjusted analyses preclude definitive conclusions. These findings should be considered hypothesis-generating, requiring confirmation in adequately powered, larger prospective studies.</p>