2.1 Study Setting and Period

The research was conducted at Bichena Primary Hospital, situated in Northwest Ethiopia, approximately 265 km away from Addis Ababa, the capital of Ethiopia. Bichena Primary Hospital is part of the Amhara regional state and falls under the administration of the Amhara Regional Health Bureau. It is located in Bichena Town within the East Gojjam Zone and was established in the Ethiopian calendar year 2007 (EC). The hospital serves a catchment population of 522,000, comprising 261,522 males and 260,478 females, attending to approximately 58,960 patients annually. The facility is equipped with 36 inpatient beds and conducts around 958 emergency abdominal operations within a 2-year span. The hospital's workforce consists of 216 staff members, including 113 health professionals.

2.2 Study Design

An institution based retrospective cross-sectional study was conducted.

2.3 Source Population

All patients who underwent surgery and were admitted to Bichena Primary Hospital.

2.4 Study Population

All patients who underwent open abdominal surgery and were admitted to Bichena Primary Hospital between September 1, 2022, and August 31, 2023.

2.5 Eligibility Criteria

This study included patients of all ages who underwent open abdominal surgeries, irrespective of the circumstances surrounding the surgery. However, certain exclusions were applied. Patients who underwent abdominal surgery at a different hospital and were subsequently referred to Bichena Primary Hospital were excluded from the study. Additionally, cases resulting in patient death within 3 days post-surgery were excluded. Furthermore, patients with incomplete medical charts were also excluded from the analysis.

2.6 Sample Size and Sampling

The sample size for the study was determined utilizing the single population proportion formula, taking into account a proportion of surgical site infection (P = 12.3%) from a previous study [23], with a 95% confidence level, a 5% margin of error, and a 10% contingency. Based on these parameters, the estimated sample size was 183. All records of abdominal operations conducted at Bichena Primary Hospital between September 2019 and August 2020 were identified through the examination of operation room, surgical ward, and recovery log books. From these log books, a list of medical record numbers (MRN) pertaining to patients who underwent abdominal operations and were admitted to Bichena Primary Hospital during the retrieval period was compiled. Subsequently, a simple random sampling technique was applied to select the required sample of 183 patients for the study.

2.7 Data Collection Tool and Procedure

A checklist derived from the World Health Organization (WHO) Surgery Safety guidelines and the Nosocomial Infection National Surveillance Scheme (NINSS), developed collaboratively by NINSS and the Centers for Disease Control and Prevention (CDC) [26, 27], was adapted to align with the specific objectives and characteristics of this study and its setting. This modified tool was utilized for data extraction from the study participants.

The data collection process was carried out by two Bachelor of Science (BSc) nurses who underwent training specifically for this data collection task. A checklist, tailored for the purpose of this study, was prepared to guide the data collection process. Information encompassing socio-demographic details, clinical factors, and pre- and intra-operative data relevant to surgical site infection (recorded at the initiation of treatment) was retrieved from the patients' records.

2.8 Data Quality Control

Data quality was ensured through the utilization of a standardized checklist derived from the WHO Surgery Safety guidelines and the NINSS [26], which was tailored for the specific requirements of this study. Before the actual survey, the modified checklist underwent a pretest involving 5% of the study sample size. Adjustments were made to the checklist based on the insights gained from the pretest. The investigator provided daily supervision throughout the data collection process. Regular checks for completeness, accuracy, and consistency of the collected data were conducted by the investigator on a daily basis.

2.9 Variables in the Study

Socio-demographic attributes such as age, sex, and residence, as well as clinical factors like the type of anesthesia administered (categorized as general or regional), the circumstance under which the surgery took place (emergency or elective), the utilization of prophylactic antibiotics, wound contamination classes at time of surgery (ranging from clean to dirty), the presence of additional comorbidities, malignancy, diabetes mellitus, immunosuppressant usage, associated medical illnesses, operative findings, the timing of the procedure, and the duration of hospital stay, were evaluated to determine their association with the dependent variable, which is the occurrence of surgical site infection.

2.10 Operational Definition

Surgical site infection: an infection that occurs after abdominal surgery on the site where the surgery took place and which is diagnosed by the clinician (yes/no).

Abdominal Operation: a surgical procedure that is done in the person's abdominal region to diagnose or treat a medical condition (CDC, 2018).

Comorbidity: any medical condition known during the time of surgery and has been written on the chart of the patients.

Length of hospital stay: In this study, the length of hospital stay was measured as the total number of days a patient spent in the hospital. To facilitate the analysis, the duration was categorized into four groups; 5–7 days, 8–14 days, 15–21 days, and ≥ 22 days. The cut-off of 22 days was selected based on a natural distribution of the data, where most patients had shorter stays. This categorization allowed for analysis of the relationship between hospital stay duration and the risk of surgical site infections.

2.11 Data Processing and Analysis

The collected data underwent a thorough examination for completeness, identification of inconsistencies, and detection of missing values. Subsequently, the data were coded and input into Epi-data version 4.6, then exported for analysis using SPSS version 25. Both bivariable and multivariable analyses were conducted to pinpoint factors associated with surgical site infections.

In the multivariate analysis, various established risk factors linked to the development of SSIs were assessed. Multivariate stepwise logistic regression analyses were employed to account for multiple predictive factors and their potential interactions. A significance level of 0.25 was set for entry into the model. The independence of these factors was characterized using multivariable χ2 and p-values. The relationship between the outcomes of interest and each independent factor was quantified using odds ratios (OR) and 95% confidence intervals (95% CI). All tests were two-sided, and significance was established at p < 0.05.

The multivariate goodness-of-fit was evaluated using the Hosmer-Lemeshow test (0.762). Predictive validity was assessed by calculating the area under the receiver operating characteristics (AUROC) curve. The interpretation of accuracy based on the AUROC curve considered the model as poor if within 0.51 and 0.69, useful if within 0.70 and 0.79, and good if ≥ 0.80. The results were conveyed through narrative text, tables, and graphs.

2.12 Ethical Consideration

The ethical considerations of this study were reviewed and approved by the Ethical Committee of Bahir Dar University, College of Medicine and Health Sciences. Additionally, official permission to conduct the study was obtained from Bichena Primary Hospital. The purpose of the study was communicated to supportive staff, including card room workers and surgical staff, and informed, voluntary, written, and signed consent was obtained from the head of the hospital. Measures were put in place to ensure the confidentiality of patient information throughout the study process.

3.1 Socio-Demographic Characteristics of Study Participants

A total of 164 patient charts were scrutinized in the investigation, excluding 19 charts due to incomplete information. The mean age of the study participants was 28.4 years (standard deviation = ±8 years), ranging from 8 to 87 years. The majority of respondents (51.8%) fell within the age bracket of 25–64 years. Children under the age of 15 accounted for 11 (6.7%) individuals, while elders aged 65 and above constituted 32 (19.5%) of the participants. The median (IQR) length of stay was 11(7) days with the majority 78 (47%) of patients stayed less than 7 days. Among all patients, 99 (60.4%) were male, and the majority (73%) of the study participants hailed from rural areas. Out of all the individuals in the study, 120 patients (constituting 73.2%) experienced a waiting period exceeding 24 h for their surgery after being admitted to the hospital, as shown in Table 1.

3.2 Comorbidity, Wound Class, and Preoperative Characteristics

In the entire cohort under investigation, 36 individuals (constituting 22% of the total participants) presented with a concurrent medical condition. Within this subgroup, HIV/AIDS was identified in 13 cases (36.2%), hypertension in 8 patients (22.2%), diabetic mellitus in 8 cases (22.2%), and anemia in 7 cases (19.4%). Out of all subjects included in the study, 19 individuals (11.6%) had undergone blood transfusion before surgery, and preoperative prophylactic antibiotics were administered to 142 patients (86.6%) before their operations. The majority of patients (84.8%) received general anesthesia, and iodine served as the primary antiseptic for most cases (56.7%). Additionally, the majority of patients (n = 145) experienced a blood loss of less than 1000 mL during the surgical procedure, as shown in Table 2.

3.3 Reason for Surgery and Case Related Characteristics

The preponderance of procedures conducted consisted of emergency abdominal operations, constituting 139 cases (84.8%). Within this category, 15 cases (10.8%) were categorized as traumatic, while 124 cases (89.2%) were deemed non-traumatic. Specifically, in the overall pool of abdominally operated cases, acute appendicitis represented 42 cases (25.6%), peritonitis accounted for 27 cases (16.5%), large bowel obstruction for 17 cases (10.4%), small bowel obstruction for 14 cases (8.5%), perforated peptic ulcer disease for 14 cases (8.5%), compound bowel obstruction for 6 cases (3.7%), and trauma for 15 cases (9.1%). Of the total traumatic cases (n = 15), thoracic-abdominal injury constituted 6 cases (40%), penetrating abdominal injury for 7 cases (46.6%), and blunt abdominal injury for 2 cases (13.3%), as presented in Table 3.

3.4 Magnitude of Surgical Site Infection

Out of the 164 patients who underwent abdominal operations, 44 patients developed surgical site infections, resulting in an incidence rate of 26.8% (95% CI: 20.1%–33.5%). Among the observed cases of surgical site infections, superficial SSI accounted for 27 (16.5%) cases, followed by deep postoperative SSI with 14 (8.5%) cases, and organ space infections with 3 (1.8%) cases.

3.5 Factors Associated With Surgical Site Infection

In the bivariable analysis, factors associated with surgical site infection development (p-value < 0.25) included patient age (p = 0.033), associated medical illness (p = 0.002), wound contamination class at surgery (p = 0.001), total hospital stay duration (p = 0.020), type of antiseptic used (p = 0.105), and estimated intraoperative blood loss volume (p = 0.116). However, in multivariable logistic regression, only associated medical illness and hospital stay length were significantly linked to surgical site infection. Patients with pre-existing medical conditions were more than three times as likely to develop a surgical site infection (SSI) compared to those without such conditions (AOR = 3.37, 95% CI: [1.32, 8.60], p < 0.001). Additionally, the likelihood of developing SSI decreased significantly with shorter hospital stays. Specifically, patients who stayed for 5–7 days had a 91% lower chance of developing SSI (AOR = 0.09, 95% CI: [0.07, 0.95], p = 0.002). Similarly, those who stayed 8-14 days had a 78% lower likelihood (AOR = 0.22, 95% CI: [0.08, 0.75], p = 0.005), and patients who stayed 15-21 days had a 72% lower chance (AOR = 0.28, 95% CI: [0.05, 0.60], p = 0.001) of developing SSI compared to patients with postoperative stays longer than 22 days, as presented in Table 4.

4.1 Strengths and Limitations of Study

The main outcome was derived from information collected through secondary data sources, but a significant number of values were missing. This may impact the accuracy of the research findings. Additionally, the data was retrospectively gathered through chart reviews, introducing limitations in ensuring data quality. Notably, there is a lack of published data on the prevalence of surgical site infections and related factors among patients who underwent abdominal operations in our country. The study revealed noncompliance with perioperative protocols, including issues like inadequate glove and dressing changes by surgeons. Violations of protocols in the surgical ward were noted due to a shortage of surgical materials, raising concerns about improper wound care and contamination. The study covered outpatient SSIs but acknowledged potential underreporting due to patients lost to follow-up after outpatient surgery, highlighting uncertainty in post-discharge surveillance accuracy and hindering precise SSI rate determination.