Gastrointestinal Surgical Outcomes Study (GISOS): a 30-day monocentric prospective cohort study in Ethiopia

Strengths and limitations of this study

  • This was a prospective cohort study with a sufficient sample size.

  • Data collection was performed using standardised and validated procedures and instruments, which enhanced its internal validity.

  • One limitation of the study was its single-centre nature and exclusion of oesophageal procedures.

Introduction

Surgical healthcare had been neglected on the global public health agenda for centuries,1 but over the past two decades, it has gained significant traction.2 Globally, surgical conditions contribute to 28%–32% of the burden of disease.2 The Lancet Commission on Global Surgery highlighted that more than 5 billion individuals lack access to safe, affordable, and acceptable surgical and anaesthetic care.2 In 2012, an estimated 313 million surgeries were performed worldwide, with only a small fraction—6.3% and 23%—taking place in very low-income and low-income countries, which account for around 37% and 34% of the global population, respectively.3 Since 2015, there has been a resurgence of interest in surgical healthcare as a critical global public health concern.2 The Lancet Commission on Global Surgery identified six core indicators, later adopted by the WHO in a list of 100 quality indicators,4 and by the World Bank as development indicators.5 Gastrointestinal surgical healthcare plays a pivotal role in addressing a broad spectrum of medical conditions, saving lives, reducing healthcare costs and minimising long-term disability.6 Gastrointestinal surgical conditions pose a substantial burden of mortality, morbidity, disability, emergency healthcare expenditures and hospital bed occupancy on a global scale, with low/middle-income countries (LMICs) bearing a disproportionate share of this burden.6 Evidence obtained from global scale indicates that gastrointestinal diseases rank third—following cardiovascular conditions and neoplasms—in terms of mortality and disability-adjusted life years in Africa, including countries like Ethiopia.7 Postoperative mortality rates serve as a crucial metric reflecting the quality of surgical care, healthcare infrastructure and the effectiveness of healthcare delivery systems. Postoperative complications significantly contribute to the burden of surgical morbidity and act as key indicators of healthcare quality, infrastructure adequacy and human resource capacity. Data on surgical outcomes from Africa,8 Europe9 and international studies10 highlight that postoperative mortality rates vary based on regional and national levels of Sociodemographic Index (SDI). Every year, over 4.2 million individuals worldwide face mortality within 30 days postsurgery, representing 7.7% of all global deaths.11 Remarkably, LMICs account for more than half of these postoperative fatalities, ranking surgical complications as the third most common cause of death following ischaemic heart disease and stroke. The burden of perioperative mortality and morbidity related to gastrointestinal surgical procedures varies based on factors such as human resource capacity, Human Development Index (HDI), existing healthcare infrastructure, urgency of surgery and policy commitment. In a multicentre prospective cohort study encompassing 25 African countries, surgical-related complications and mortality rates were reported at 18% and 2%, respectively.8 Similarly, findings from a cohort study in Cameroon highlighted postoperative complication and mortality rates of 33.3% and 10%, respectively, between 2019 and 2020.12 While comprehensive data on surgical outcomes related to gastrointestinal conditions in Ethiopia remains scarce, a meta-analysis of seven retrospective cohort studies involving 2053 patients with surgical acute abdomen in Ethiopia reported postoperative complication and mortality rates of approximately 20% and 5%, respectively.13 This study aims to delve into the incidence of 30-day postoperative mortality, morbidity and associated factors following gastrointestinal surgeries at a high-volume surgical centre in Ethiopia, shedding light on the challenges and outcomes in this specific healthcare setting.

Methods

Study area and period

This 30-day prospective observational cohort study was conducted in Tikur Anbessa Specialized Hospital which is the leading high-volume surgical centre in Ethiopia. The study began on 1 January 2023 and ended 30 August 2023. All consecutive patients undergoing elective and non-elective surgical procedures of oesophagus, stomach, small intestine, colorectal, liver, biliary, pancreas anal and appendix with general anaesthesia during the 30-day study period (0000 day 1 to 2400 day 30) with a planned overnight stay were included.

Primary outcome of the study

The primary outcome of this study was 30th-day mortality and complications rates after gastrointestinal surgery.

Sampling size

Sample size was determined with taking the pooled complication rates (20%), which was obtained from meta-analysis of surgical acute abdomen outcomes in Ethiopia, a margin of error to be 5%, a confidence level of 95% and considering a non-response rate of 10%, the representative sample of participants will be determined using a single proportion formula for a cross-sectional survey as follows:

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and 10% loss follow-up, 258 patients

Data collection procedure

Data were collected in the study hospital using electronic case record forms (CRFs). Data collectors checked, coded and transcribed daily. The paper CRFs were written in English. CRF was adopted from global studies with minimal local modification. The questionnaire tool was also pretested outside of studies hospital. Previously published literature was used to adapt and develop the tools. The data were collected by residents. Training was provided for data collectors. Data were collected when the patients in hospital, during their SRC follow-up and phone call follow-up if necessary.

Statistical analysis

The data was checked, coded and entered into SPSS V.25 for analysis. Graphs and tables were used to present the data. Categorical variables were described in terms of frequency and percentage, and comparisons were made using χ2 or Fisher’s exact tests. Continuous variables were tested for normality using the Shapiro-Wilk test and presented as mean with SD (mean±SD) for normally distributed data or median with IQR (median±IQR) for non-normally distributed data. Univariate analysis was conducted to assess factors associated with 30-day mortality and postoperative morbidity. Variables with a p value of 0.25 or less in the univariate analysis were entered into the multivariable binary logistic model. A multiple logistic regression model was used to identify independent risk factors, with a multicollinearity test conducted for categorical, continuous and binary variables, measured by variance inflation factor (VIF) and tolerance. Variables with a VIF score below five and tolerance above 0.1 were included in the multivariable logistic regression analysis, while those with a VIF score of >10 and tolerance below 0.1 were excluded from the final model. A stepwise approach was used to enter new terms into the logistic regression model, with a significance level of p<0.05 for inclusion. A logistic regression model was then performed to determine the independent association between prognostic factors and outcomes, with results reported as adjusted ORs with 95% CIs. A p value <0.05 was considered statistically significant.

Patient and public involvement

Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

Results

Between 1 January 2023 and 30 July 2023, a total of 275 patients underwent gastrointestinal surgery. Excluding oesophageal procedures due to outlier results, as well as eliminating eleven patients with inadequate follow-up and five patients of poor quality, data from 259 patients were collected and analysed during this prospective observational study. In terms of gender distribution, males accounted 54.1% of the participants, while females accounted for 45.9%. The median age of the participants in the study was 42 years (±IQR=29.7). The most common procedures performed were related to gall bladder, biliary tree and colon surgeries. Additionally, a majority of the participants had an Eastern Cooperative Oncology Group (ECOG) status of 0 (68%) and an ASA (American Society of Anesthesiology) status of 1 (67.6%). The comorbidity rate was 13.5%, with a high percentage (79.2%) having a Charlson Comorbidity Index score falling within the range of 0–5 (table 1).

Table 1

Sociodemographic, clinical diagnosis and functional status of participants in Gastrointestinal Surgical Outcomes Study in Tikur Anbessa Specialized Hospital, Addis Ababa, 2023

Surgical outcomes

Surgical outcomes serve as crucial quality and development indicators recognised by the WHO and the World Bank for each country. Postoperative mortality and morbidity play significant roles in global mortality rates, levels of disability and economic repercussions. In this prospective observational study, it was observed that the 30-day complication rate stood at 30.5%. Among these complications, surgical site infections emerged as the most frequent at 15.8%, followed by postoperative acute kidney injury (AKI) at 9.3%. The morbidity rate, classified under Clavien-Dindo class III and IV, was recorded at 14.7%. In the analysis, variables such as age, sex, type of surgery, comorbidities, Charlson Comorbidity Index score, ASA status and ECOG status were included for multivariable binary logistic regression following univariate binary logistic regression. After controlling for confounding factors, malignant pathology (adjusted OR (AOR)=1.43 (1.01 to 3.06); p=0.035), ASA status III (AOR=4.00 (1.01 to 16.5); p=0.049), ECOG status III (AOR=2.8 (1.55 to 7.30); p=0.025) and comorbidities (AOR=2.02 (1.02 to 3.18); p=0.008) exhibited statistically significant associations with the 30-day complication rates (tables 2 and 3).

Table 2

A 30-day complication rate, morbidity and type of complications in Gastrointestinal Surgical Outcomes Study in Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia 2023

Table 3

Univariable and multivariable binary logistics regression analysis to identify associated factors for 30-day complication rate after gastrointestinal surgery in Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia, 2023

In this prospective observational study, the study found a 30-day mortality rate of 14.3% following gastrointestinal surgery. Notably, the mortality rate at 30 days was markedly higher among patients with malignant pathology compared with those with benign pathology (22.4% vs 7.7%). On initial univariate binary logistic regression analysis, a range of factors including age, sex, disease category, timing of surgery, ECOG status, ASA status, comorbidities and Charlson Comorbidity Index score showed associations with the 30-day mortality rate. On adjusting for confounding variables, several factors emerged as significantly associated with the 30-day mortality rate after gastrointestinal surgery. These factors included emergency surgery (AOR=5.53 (1.4 to 21.6); p=0.014), ECOG status III (AOR=8.6 (1.01 to 74.1); p=0.0499), ASA status III (AOR=12.7 (1.9 to 85.5); p=0.009) and comorbidities (AOR=7.5 (1.4 to 39.1); p=0.017), establishing statistically significant associations with the 30-day mortality rate post-gastrointestinal surgery (table 4).

Table 4

Univariable and multivariable binary logistics regression analysis to identify associated factors for 30-day mortality after gastrointestinal surgery in Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia, 2023

Discussion

As far as our knowledge extends, this marks the initial prospective investigation revealing surgical mortality and morbidity rates within a high-volume surgical facility in Ethiopia. Postoperative mortality and morbidity play substantial roles in global mortality rates, disability and economic impacts. According to the results of this prospective observational study, the 30-day surgical complication rate stood at 30.5%. Notably, this figure surpasses comparative data extracted from studies conducted in Africa,8 Europe9 and on an international scale.10 This highlights a significant disparity in surgical outcomes that warrants further exploration and intervention to enhance patient care and well-being in surgical settings within Ethiopia. In a groundbreaking international prospective multicentre international study encompassing 44 814 patients across 474 hospitals, the overall surgical complication rate was estimated at around 17%.10 Similarly, the African Surgical Outcome Study (ASOS) conducted in 2016 involving 11 422 patients from 247 hospitals revealed a comparable overall surgical complication rate of approximately 18%.8 Moreover, a meta-analysis pooling data from seven retrospective cohort studies comprising 2053 patients with surgical acute abdomen cases in Ethiopia reported a postoperative complication rate of about 20%. This variance in complication rates compared with previous local and global findings suggests several potential contributing factors. Differences in study settings, the SDI of countries, healthcare provider capabilities and patient-related factors have been identified as primary influencers on the observed disparity in surgical complication rates. Understanding these factors is crucial for improving surgical outcomes and enhancing patient care in diverse healthcare settings. In this study, the 30-day complication rate was notably associated with several factors including ASA III, high Charlson Comorbidity Index score, ECOG III, comorbidities, malignancy and advanced age. These findings align with numerous studies conducted across varied settings, healthcare policies and HDI rankings. The ASOS findings supported these results, highlighting associations between postsurgical complications and factors like older age, ASA physical status, surgical indication, urgency, severity and surgery type. This consistency across studies underscores the importance of these factors in influencing surgical outcomes and patient care across different healthcare landscapes.

In our prospective observational study, we found a 30-day mortality rate of 14.3% following gastrointestinal surgery. Comparatively, existing literature has presented varying mortality rates following surgical procedures for diverse conditions. For instance, a multicentre International Surgical Outcome Study involving over 44 000 patients from high-SDI, middle-SDI and low-SDI countries indicated an overall surgical mortality rate of 0.5%.10 The European Surgical Outcome Study, spanning 28 countries and 498 hospitals in 2012, exhibited surgical mortality rates ranging from 1.2% to 22%.9 In 2016, the ASOS involving more than 11 000 patients reported a 30-day surgical mortality rate of 2%.8 A population-based prospective cohort study in Denmark that included 2904 gastrointestinal surgical patients documented a 30-day mortality rate of approximately 19%.14 Similarly, a cohort study in Cameroon demonstrated a mortality rate of 10% following non-traumatic gastrointestinal surgeries from 2019 to 2020.12

These discrepancies in mortality rates can be attributed to various factors, including patient characteristics, economic conditions of the country, healthcare development and community health-seeking behaviours. Understanding these factors is essential for addressing disparities in surgical outcomes and improving overall patient care and survival rates across different healthcare systems and regions.

This study delved into the examination of the 30-day mortality rate post-gastrointestinal surgery, uncovering associations with factors like ECOG III, emergency surgery, ASA III, comorbidities and a high Charlson Comorbidity Index score. These findings echo earlier research conducted across diverse healthcare settings, human resource development contexts and national income strata, underscoring the importance of these variables in predicting surgical outcomes. A comprehensive multicentre North American series under the National Safety and Quality Improvement Programme observed that a three-point procedure risk grading alongside ASA status and urgency levels could serve as effective predictors of surgical mortality.15 Similarly, the Perioperative Mortality Review Committee in New Zealand established a national framework, revealing that age, admission urgency, ASA classification and procedure type were significant prognosticators of 30-day mortality postsurgery.16 Moreover, the National Confidential Enquiry into Patient Outcome and Death scrutinised data from 16 788 patients across 326 hospitals in the UK to develop the Surgical Outcome Risk Tool. The analysis identified age 65 or older, cancer diagnosis, high-risk surgical specialties (involving gastrointestinal, thoracic or vascular procedures), varying surgical complexities (ranging from minor to complex major surgeries) and the urgency of surgery (ranging from expedited to immediate) as pivotal predictors of 30-day mortality.17 These insights emphasise the critical role of these factors in assessing and predicting the outcomes of surgical procedures, aiding in informed decision-making and optimising patient care strategies within the realm of surgical interventions. We recognise that various factors such as a higher ASA class, ECOG performance status, advanced age, and emergency procedures contribute to increased risks of mortality and complications in medical settings. These risks are evident in both high-income and low-income countries, but the disparity lies in the availability of advanced surgical care to address these challenges.

The results of our prospective cohort study have unveiled elevated rates of mortality and complications, shedding light on critical insights with broad implications for clinicians, advocates of global surgery, policymakers and researchers. The documented high mortality and complication rates uncovered by our study offer valuable insights that can directly influence and enhance clinical practice. By understanding the prevalence and patterns of adverse outcomes, clinicians can adapt their approaches, implement targeted interventions and improve patient care strategies to mitigate risks and optimise surgical outcomes. For advocates of global surgery, the findings from our study serve as a critical resource in advocating for improved access to safe and effective surgical care worldwide. By highlighting the challenges and complexities associated with surgical outcomes, our research contributes to the discourse on global surgery equity, resource allocation and capacity building, promoting initiatives that aim to address disparities in surgical care on a global scale. Policy makers can leverage the findings of our study to inform evidence-based policy decisions and healthcare strategies aimed at enhancing patient safety, reducing mortality and improving surgical outcomes. The data on mortality and complication rates provide a foundation for designing targeted interventions, quality improvement initiatives and regulatory frameworks that prioritise patient well-being and quality of care. The research outcomes presented in our study serve as a catalyst for further exploration and investigation within the research community. By identifying areas of concern and highlighting the need for continued inquiry, our findings inspire researchers to delve deeper into understanding the underlying factors contributing to adverse surgical outcomes, fostering innovation, knowledge advancement and the development of effective solutions to enhance surgical care practices. Collaboration among clinicians, advocates, policymakers and researchers is essential in translating the implications of our study findings into actionable strategies that drive positive change in surgical care delivery. Together, we can work towards implementing evidence-based interventions, advocating for policy reforms, and advancing the collective goal of improving patient outcomes and ensuring safer surgical practices globally.

Conclusion

The results of this study have revealed a concerning trend of heightened postoperative mortality and complications, underscoring the urgency for novel interventions to mitigate these adverse outcomes. The substantial rates of postoperative mortality and complications emphasise the pressing need for innovative strategies aimed at reducing the incidence and severity of these surgical complications. Identifying and addressing modifiable risk factors, including SSI, AKI and other contributing factors, is crucial for reducing mortality rates following surgery. These risk factors play a significant role in shaping postoperative outcomes and represent actionable points for intervention and improvement in surgical care practices. To effectively address the challenges posed by postoperative mortality and complications, a comprehensive and multidisciplinary approach is required. By targeting modifiable risk factors, implementing evidence-based guidelines, enhancing infection control measures and optimising perioperative care protocols, healthcare providers can work towards reducing the incidence of postoperative complications and improving patient safety and outcomes.

Data availability statement

Data are available upon reasonable request.

Ethics statements

Patient consent for publication

Ethics approval

In this research study conducted at the Department of Surgery, College of Health Sciences, Addis Ababa University, ethical approval was sought and obtained from the Institutional Review Board (IRB-Sur. 15-2023). Prior to the commencement of the study, verbal informed consent was obtained from each participant. This process involved the participant’s agreement after a clear explanation of the study’s purpose, procedures, risks and benefits. The consent was documented in the presence of two data collectors and an attendant to ensure transparency and understanding. The principal investigator, as the leader of the research project, played a crucial role in emphasising the importance of obtaining ethics approval and took the necessary steps to secure it. To uphold participant confidentiality, identifying information such as names and medical record numbers was excluded from the data collection forms. This precautionary measure was implemented to protect the privacy and anonymity of the participants throughout the study process. The study upheld the principles and guidelines outlined in the Declaration of Helsinki, a foundational document in medical research ethics. By following these ethical standards, the study demonstrated a commitment to respecting the rights, autonomy and well-being of the participants involved. By incorporating these ethical considerations and practices into the research process, the study-maintained integrity, transparency and respect for the participants, thereby contributing to the credibility and validity of the study outcomes.

Acknowledgments

We would like to express our sincere and deep-rooted thanks to data collector for the support provided since the training on the final submission of the manuscript.

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