Hospital mortality of blunt abdominal aortic injury (BAAI): a systematic review and meta-analysis

Background Studies on the mortality of blunt abdominal aortic injury (BAAI) are rare and have yielded inconsistent results. In the present study, we aimed to quantitatively analyse the retrieved data to more accurately determine the hospital mortality of BAAI. Methods The Excerpta Medica Database, PubMed, Web of Science and Cochrane Library databases were searched to identify relevant publications without date restrictions. The overall hospital mortality (OHM) of BAAI patients was set as the primary outcome measure. English publications with data that met the selection criteria were included. The quality of all included studies was assessed by the Joanna Briggs Institute checklist and the American Agency for Health Care Quality and Research’s cross-sectional study quality evaluation items. After data extraction, a meta-analysis of the Freeman–Tukey double arcsine transformation of data was performed using the Metaprop command in Stata 16 software. Heterogeneity was assessed and reported as a percentage using the I2 index value and as a P value using the Cochrane Q test. Various methods were used to determine the sources of heterogeneity and to analyse the sensitivity of the computation model. Results Of the 2147 references screened, 5 studies that involved 1593 patients met the selection criteria and were included. There were no low-quality references after assessment. One study that only included 16 juvenile BAAI patients was excluded from the meta-analysis of the primary outcome measure due to high heterogeneity. Due to the low heterogeneity (I2 = 47.6%, P = 0.126 for Q test) that was observed after using the random effects model, the fixed model was subsequently used to pool the effect sizes of the remaining four studies, thus yielding an OHM of 28.8% [95% confidence interval (CI) 26.5–31.1%]. The stability of the model was verified by sensitivity analysis, and Egger’s test (P = 0.339) indicated a low level of publication bias. In addition, we also performed meta-analyses and obtained a pooled hospital mortality of operation (13.5%, 95% CI 8.0–20.0%), a pooled hospital mortality of non-operation (28.4%, 95% CI 25.9–31.0%), and a pooled rate of aortic rupture (12.2%, 95% CI 7.0–18.5%) of BAAI. Conclusions The present study indicated that BAAI has an OHM of 28.8%, indicating that this disease deserves more attention and research. Supplementary Information The online version contains supplementary material available at 10.1186/s13017-023-00492-w.


Data items 10a
List and define all outcomes for which data were sought. Specify whether all results that were compatible with each outcome domain in each study were sought (e.g. for all measures, time points, analyses), and if not, the methods used to decide which results to collect. 10b List and define all other variables for which data were sought (e.g. participant and intervention characteristics, funding sources). Describe any assumptions made about any missing or unclear information. Specify the methods used to assess risk of bias in the included studies, including details of the tool(s) used, how many reviewers assessed each study and whether they worked independently, and if applicable, details of automation tools used in the process.
Effect measures 12 Specify for each outcome the effect measure(s) (e.g. risk ratio, mean difference) used in the synthesis or presentation of results.

Synthesis methods 13a
Describe the processes used to decide which studies were eligible for each synthesis. 13b Describe any methods required to prepare the data for presentation or synthesis, such as handling of missing summary statistics, or data conversions. 13c Describe any methods used to tabulate or visually display results of individual studies and syntheses. 13d Describe any methods used to synthesize results and provide a rationale for the choice(s). If meta-analysis was performed, describe the model(s), method(s) to identify the presence and extent of statistical heterogeneity, and software package(s) used. 13e Describe any methods used to explore possible causes of heterogeneity among study results. 13f Describe any sensitivity analyses conducted to assess robustness of the synthesized results.
Reporting bias assessment 14 Describe any methods used to assess risk of bias due to missing results in a synthesis (arising from reporting biases).
Certainty assessment 15 Describe any methods used to assess certainty (or confidence) in the body of evidence for an outcome.

Study selection 16a
Describe the results of the search and selection process, from the number of records identified in the search to the number of studies included in the review, ideally using a flow diagram. 16b Cite studies that met many but not all inclusion criteria ('near-misses') and explain why they were excluded. 20c Present results of all investigations of possible causes of heterogeneity among study results. 20d Present results of all sensitivity analyses conducted to assess the robustness of the synthesized results.

Reporting biases 21
Present assessments of risk of bias due to missing results (arising from reporting biases) for each synthesis assessed.
Certainty of evidence 22 Present assessments of certainty (or confidence) in the body of evidence for each outcome assessed.

Discussion 23a
Provide a general interpretation of the results in the context of other evidence. 23b Discuss any limitations of the evidence included in the review. 23c Discuss any limitations of the review processes used.
23d Discuss implications of the results for practice, policy, and future research.

OTHER INFORMATION
Registration and protocol 24a Provide registration information for the review, including register name and registration number, or state that the review was not registered.

24b
Indicate where the review protocol can be accessed, or state that a protocol was not prepared. 24c Describe and explain any amendments to information provided at registration or in the protocol.  Identify the report as a systematic review.

Objectives 2
Provide an explicit statement of the main objective(s) or question(s) the review addresses.

Eligibility criteria 3
Specify the inclusion and exclusion criteria for the review.
Information sources 4 Specify the information sources (e.g. databases, registers) used to identify studies and the date when each was last searched.
Risk of bias 5 Specify the methods used to assess risk of bias in the included studies.
Synthesis of results 6 Specify the methods used to present and synthesize results.

Included studies 7
Give the total number of included studies and participants and summarise relevant characteristics of studies.
Synthesis of results 8 Present results for main outcomes, preferably indicating the number of included studies and participants for each.
If meta-analysis was done, report the summary estimate and confidence/credible interval. If comparing groups, indicate the direction of the effect (i.e. which group is favoured).

DISCUSSION
Limitations of evidence 9 Provide a brief summary of the limitations of the evidence included in the review (e.g. study risk of bias, inconsistency and imprecision).
Interpretation 10 Provide a general interpretation of the results and important implications.

Funding 11
Specify the primary source of funding for the review.

Registration 12
Provide the register name and registration number.