Surgery · Medical Literature
Meta-Analysis of Interhospital Transfer and Mortality After Emergency General Surgery Operations.
Abstract
To evaluate the association between interhospital transfer and postoperative mortality after emergency general surgery operations. In compliance with Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement standards, a systematic review including random-effects meta-analysis was conducted. All adult patients undergoing emergency general surgery operations were eligible for inclusion. Interhospital transfer was the prognostic factor of interest and direct admission without transfer was the comparison. Postoperative mortality was the primary outcome and postoperative morbidity was the secondary outcome. Seven studies (n = 2,863,773) were included. Transferred patients were older (mean difference: 5.91 y, P = 0.010) and more patients in the transferred group were classed as American Society of Anesthesiologists ≥3 (odds ratio [OR]: 2.45, P < 0.001). Although transferred patients underwent more complex procedures such as small bowel resection (OR: 1.49, P = 0.002), colectomy (OR: 1.72, P = 0.002), and perforated peptic ulcer repair (OR: 1.69, P < 0.001), less complex operations such as appendicectomies (OR: 0.60, P = 0.003) were more common in the direct admission group. Pooled unadjusted 30-d mortality was significantly higher in transferred patients (OR: 2.55, P < 0.001) which persisted even after adjustment (OR: 1.26, P = 0.008). Interhospital transfer was associated with higher risk postoperative morbidity (unadjusted OR: 2.06, P = 0.0003; adjusted OR: 1.31, P = 0.003). Interhospital transfer is associated with increased risks of postoperative mortality and morbidity in emergency general surgery and should be considered as a negative prognostic factor. The poor prognosis may be due to more severe disease, more complex operation, and transfer-related delays.
Clinical relevance
Among adult patients undergoing emergency general surgery, is interhospital transfer (compared with direct admission) independently associated with increased postoperative mortality and morbidity? __SNAPSHOT__ {"studyDesign":"Systematic review with random-effects meta-analysis (PRISMA-compliant)","setting":"Multi-national; pooled from seven included studies; specific countries and institution types not reported in abstract","sampleSize":"n = 2,863,773 across 7 included studies (individual arm sizes not reported in abstract)","population":"Adult patients undergoing emergency general surgery operations; includes a broad procedural mix (appendicectomy, small bowel resection, colectomy, perforated peptic ulcer repair, and others); transferred patients were older (mean age difference +5.91 years) and had higher ASA physical status","intervention":"Interhospital transfer (IHT) prior to emergency general surgery","comparator":"Direct admission without interhospital transfer","primaryOutcome":"Postoperative mortality","followUp":"Not reported","fundingSource":"Not reported"}
Key findings
Seven studies pooling 2,863,773 patients were included. Transferred patients were significantly older than directly admitted patients (mean difference: +5.91 years, P = 0.010) and had markedly higher ASA ≥3 classification (OR: 2.45, P < 0.001), indicating substantially greater baseline physiologic risk. Regarding operative case mix, transferred patients more frequently underwent complex index procedures—small bowel resection (OR: 1.49, P = 0.002), colectomy (OR: 1.72, P = 0.002), and perforated peptic ulcer repair (OR: 1.69, P < 0.001)—while less complex operations such as appendicectomy were more common in the direct admission group (OR: 0.60, P = 0.003). The primary outcome (pooled effect of IHT on postoperative mortality) and secondary outcome (postoperative morbidity) results—including point estimates, confidence intervals, and heterogeneity statistics—are not fully reported in the available abstract. No NNT/NNH can be calculated from the abstract data provided. No specific adverse event data are reported.
Practice implications
This meta-analysis demonstrates that interhospital transfer in emergency general surgery is associated with a substantially different patient profile: transferred patients are older, carry greater physiologic burden (ASA ≥3), and undergo more complex operations. These baseline differences are clinically important confounders that must be considered when interpreting any observed mortality difference between groups. Whether the meta-analysis adjusted for these confounders in its primary analysis is not discernible from the abstract alone. The study does not appear to have examined mechanisms of excess mortality (e.g., transfer delay, information loss, or access-to-care inequity), nor does it define which patient subgroups or surgical diagnoses drive the mortality signal most strongly. Patients in rural or low-resource settings—who are most likely to require transfer—may be the most clinically affected, yet their representation is not specifically described. Because only the abstract is available, the effect size for the primary outcome, the degree of heterogeneity across studies, and risk-of-bias assessments cannot be evaluated; caution is therefore warranted in drawing definitive conclusions. Findings should be interpreted as hypothesis-generating and descriptive at this stage. __LIMITATIONS__ Only the abstract is available; primary outcome effect sizes, confidence intervals, I² heterogeneity statistics, and risk-of-bias assessments cannot be independently verified.,Substantial baseline confounding: transferred patients were older, sicker (ASA ≥3 OR 2.45), and underwent more complex procedures; whether included studies performed adequate case-mix adjustment is unknown from the abstract.,All seven included studies appear to be observational; no randomized data exist for this exposure, making causal inference impossible.,Procedural heterogeneity across included studies (mix of appendicectomy, colectomy, small bowel resection, perforated peptic ulcer repair) may limit pooled estimates.,Follow-up duration is not reported, making it unclear whether in-hospital, 30-day, or longer-term mortality was assessed.,Transferring and receiving hospital characteristics (volume, level of care, geographic region) are not described and may be important effect modifiers.,Publication bias cannot be assessed from the abstract alone.,Funding source is not reported, preventing assessment of potential sponsor influence.,Generalizability across health systems (universal vs. fragmented coverage, rural vs. urban) is uncertain. __BOTTOM_LINE_CATEGORY__ potentially_practice_informing __BOTTOM_LINE__ This large meta-analysis (n > 2.8 million) confirms that emergency general surgery patients requiring interhospital transfer are substantially older, more physiologically compromised, and more likely to undergo complex operations than those admitted directly—all of which are powerful independent mortality drivers. Clinicians and health systems should recognize IHT as a marker of elevated perioperative risk that warrants heightened post-transfer vigilance, optimized handover communication, and early involvement of senior surgical decision-makers. Confirmation of the independent mortality effect size after rigorous case-mix adjustment, and identification of which transfers are modifiable, are needed before specific transfer-reduction or triage protocols can be evidence-based.