Results
A total of 6,982 records were identified, and 16 new studies were included (9 suitable for meta-analysis).Together with the 20 studies from the former review (13 included in the meta-analysis), 36 studies were analyzed, 22 of which (9.3 million patients) were included in the quantitative synthesis. No statistically significant association was observed between prolonged EDLOS and in-hospital mortality for any of the cutoffs analyzed: < 4 hours (OR, 0.83; 95% CI, 0.29-2.35), $ 4 hours (OR, 0.82; 95% CI, 0.46-1.46), $ 5 hours (OR, 0.60; 95% CI, 0.21-1.70), $ 6 hours (OR, 0.95; 95% CI, 0.75-1.21), $ 8 hours (OR, 1.10; 95% CI, 0.73-1.65), and $ 24 hours (OR, 0.78; 95% CI, 0.56-1.08). Similarly, the overall meta-analysis showed no association (OR, 1.02; 95% CI, 0.85-1.23). Heterogeneity was high (I² = 80-98%; I² = 97% in the overall analysis), and no relevant publication bias was detected. Studies analyzing EDLOS as a continuous variable suggested increasing mortality with progressively longer stays. Some studies identified associations between prolonged EDLOS and longer hospitalizations, greater resource use, higher hospital costs, specific complications, and a greater need for ICU admission.