Malnutrition in the Outcome of Wound Healing at Public Hospitals in Bahir Dar City, Northwest Ethiopia: A Prospective Cohort Study

Background Poor nutritional status affects the normal process of the wound healing stage. There is limited evidence regarding the association between malnutrition and wound healing in Ethiopia. Objective To assess the association between nutritional status and wound healing progress among adult individuals who had undergone abdominal surgery at Public Hospitals, Ethiopia. Methods A prospective cohort study was conducted on 310 adult patients who had undergone abdominal surgery from August to December 2019. Data were collected using a standardized, structured, and pretested questionnaire. Anthropometric and serum albumin measurements were used to measure nutritional status. A multivariable Cox-regression analyses model was fitted to show the association between malnutrition and wound healing and p value < 0.05 was used to declare statistical significance value. Results The cumulative incidence rate of good wound healing was 65.5% (95% CI: 60.0–71.0). Patients who had normal preoperative body mass index (adjusted hazard ratio (AHR) = 2.22 (95% CI: 1.55–3.19)) and normal range of serum albumin level (≥3.5) (AHR = 1.56 (95% CI: 1.05–2.29)) were significantly associated with better wound healing outcomes. Conclusion Nutritional status had a strong association with good wound healing outcomes. Therefore, nutritional status screening should be done for all adult patients before undergoing abdominal surgery to improve wound healing outcomes and reduce hospital stays.


Background
e wound is defined as damage, disruption, or loss of the normal anatomical structure and functional continuity of living tissues accidentally, intentionally, or as a result of a disease process [1]. Wound healing is a continuing and complex process of changing injured tissue to another new tissue with the coordination of several biological and molecular events, which directly correlated to patients' overall nutritional status [2].
Poor nutritional status affects the normal process of the wound healing stage by prolonging the inflammatory phase, decreasing fibroblast proliferation, and altering collagen production which decreases wound tensile strength and increased infection rates [3,4]. Previous studies found that wound is a common surgical problem all over the world that causes significant morbidity and mortality. Approximately 3-6 million people are affected by nonhealing wounds in the United States of America [5][6][7]. e incidence rate of the postoperative complicated outcome was 4-7% in Canada, 10.33% in Barcelona city, 38.8% in Sub-Saharan Africa, and 19.1% in Ethiopia from admitted surgical patients [8][9][10][11].
e patient with hypoalbuminemia who had undergone abdominoperineal resections was more likely to increase the risk of delayed wound healing as compared with the wellnourished [12]. While on serum albumin measurement operated surgical patients with normal nutritional status had a higher probability of wound healing than the counterpart [13]. e percentage of postoperative wound healing incidence rate was 11.40% from the healthy individuals but 2.30% in malnourished patients [14]. Based on serum albumin measure, the incidence rate of delayed wound healing was 12% and 28% from the well-nourished and undernourished, respectively. Based on body mass index (BMI) measure, the incidence rate of delayed wound healing was 12% and 21% from the well-nourished and undernourished, respectively [15].
Even though the postoperative complication rate of abdominal surgery patients in the Sub-Saharan African setting is still high [16], there is limited published evidence on the incidence of wound healing associated with the effect of nutritional status among patients undergoing abdominal surgery in Sub-Saharan African especially in Ethiopia. Also, there are no nutrition screening services in Ethiopia before undergoing abdominal surgery. is makes the outcome of abdominal surgery the worst and a long hospital in Ethiopia. erefore, this study will be important to generate evidence on the association between malnutrition and wound healing progress among adult patients undergoing abdominal surgery in Ethiopia. Likewise, this study helps to change the usual trend of the integration of nutrition screening services with clinical management. e study population was adult patients (≥18 years) who underwent abdominal surgery at the surgical ward of Bahir Dar City Public hospitals. e sample size was calculated by considering 95% confidence level (CL), 80% of power (1-β), and taking nutritional status with1:1 ratio (well-nourished vs. malnourished) as exposure variable [14] and 10% nonresponse rate. e final sample size was 310 adult patients (155 for well-nourished and 155 malnourished patients) who had undergone abdominal surgery. ree hundred ten adult abdominal surgical operation patients were selected by using a systematic sampling technique. e final sample size was proportionally allocated to the selected hospitals based on their last four-month abdominal surgical operation reports. e first case was selected by lottery method and then every three cases were included for both well-nourished and malnourished patients.

Data Collection Procedure and Quality Improvement.
Data were collected using a standardized, structured, and face-to-face interviewer-administered questionnaire. e questionnaire includes the patient's sociodemographic characteristics, clinical features of patients, lifestyle and behavior of patients, and nutritional status which include the anthropometric examination and biochemical test. Data were collected by six trained B.Sc., Nurse and three trained medical laboratory technology with fluency in the local language (Amharic). Orientation, supervision, and reviewing the completed questionnaire were done to assure data quality. e data collectors measured the patient's preoperative nutritional status (BMI and serum albumin level) and followed postoperative wound healing progress with clinical features.

Anthropometric Measurements.
Body weight was measured twice to the nearest 0.1 kg, and the average reading was calculated. While measuring the body weight, each patient was asked to take off the heavy clothes and shoes to keep in light clothes and remove heavy objects such as wallet and mobile before standing on the calibrated weighing scale balance (SECA, Germany) before the operation.
Height was measured twice by using SECA calibrated Stadiometer read as in centimeter. Each individual was asked to stand as fully erected as possible as against the wall and maintain the head in a position of straight-forward gaze and feet slightly apart with the back of the head, scapulae, buttocks, and heels positioned in contact with the wall; then, the sliding bar was lowered horizontally to the participants head to where the bar was locked and the measurement read and recorded during admission. Well-nourished patients' BMI were between 18.5 and 24.9 kg/m 2 , while malnourished patients' BMI were ˂18.5 kg/m 2 (underweight) or ≥25 kg/m 2 (overweight) [17].

Biochemical
Test. Blood specimens were taken from sample patients before undergoing abdominal surgery. e medical laboratory technologists analyzed the serum albumin level as per the standard operating procedure. And then serum albumin level was classified as the normal range (>3.5 g/dl) and not the normal range (<3.5 g/dl) [17].

Wound Healing Follow-Up
Checklist. All study patients were followed-up and their wound healing characteristics were assessed throughout the 1 st , 3 rd , 5 th , 7 th , and 10 th postoperative day. e data collectors estimated and recorded the wound healing progress by assessing sign and symptom of wound healing character (bleeding, scab formation, localized pain and swelling, persistent fever, red streaks near the cut, fouler odor, darkening skin edges, clear fluid, and thick grayish discharge around incision site) within ten postoperative days based on wound healing checklist. And also the level of the surgeon, regular wound care provider, patient's medication, privies surgical history, chronic comorbidity, mode, and type of surgery was assessed.
2.6.1. Good Wound Healing. It includes patients who showed improvement regarding any sign of bleeding, swelling, localized pain, fever, redness, grayish or clear fluid discharge, and fouler odor, with the incision site filled by repaired tissue with the sign of shiny and smooth scar formation within ten postoperative days.

Poor Wound
Healing. It includes patients who had any sign of bleeding, persistent fever, red streaks near the cut, increasing localized pain and swelling, fouler odor, darkening skin edges, and thick-grayish or clear fluid discharge from the incision site until the 10 th postoperative days [18]. Finally, the patients who had good wound healing outcomes within ten postoperative days are considered as an event, and patients who had poor wound healing progress and were lost to follow-up (died, medical against, referral, defaulter, and self-discharge) until the 10 th postoperative day was considered as censored.

Statistical
Analysis. Data were checked manually for completeness and consistencies and then coded and entered into EPI Data version 3.1 software and exported to SPSS (statistical package for social science) version 23 software package for further analysis. Descriptive statistics were used to describe variables and summarize the data in the form of frequency, mean, standard deviation, cross-tabulation, table, and graph.
Multivariable Cox-regressions analysis models were used to determine the association between malnutrition and wound healing outcomes. e model assumption was checked by using Log (-Log) S (t) plots. Crude and adjusted hazard ratios with their 95% confidence interval (CI) were estimated, and P value less than 0.05 was considered as the significance level for associations between dependent and predictor variables.

Sociodemographic Characteristics of Participants.
A total of 310 patients had undergone abdominal surgery at Bahir Dar City Public Hospitals in Amhara Region. e mean ages of the patients were 39.7 ± 16.66 years (±SD). e majority (92.3%) of patients were Orthodox Christianity followers. More than half (59.4%) of the patients were from urban residency. 191 (61.6%) patients were married, and higher proportions (33.5%) of patients had attended primary education. More than half (57.4%) of patients were recruited from FHCSH (Table 1).  (Table 3).

Outcomes of Wound Healing.
e overall incidence rate of good wound healing was 65.5% (95% CI: 60.0-71.0). From normal preoperative BMI patients, 88.4% had a good wound healing incidence rate whereas malnourished preoperative patients, 42.6%, had a good wound healing incidence rate. Likewise, from well-nourished preoperative patients in serum albumin measurement, 86.0% had good wound healing outcomes. Preoperative malnourished patients in serum albumin measurement had 40.3% of good wound healing outcomes.

Malnutrition and Wound Healing Outcomes.
Before fitting the covariate into the model, the proportional hazard assumption was checked using Log (-Log) S (t) plots. e final model was adjusted with the type of medication, type of surgery, acute illness, chronic comorbidity, smoking, age of patients, and sex to know the association between malnutrition and wound healing outcomes. In the multivariable Cox regression analysis model, BMI and serum albumin test level were significant predictors of wound healing among adult patients who underwent abdominal surgery.
Patients who had the normal preoperative body mass index were 2 times more likely to have good wound healing incidence rate outcomes as compared to those malnourished patients (AHR � 2.22 (95% CI: 1.55-3.19)). Patients who had a normal range of serum albumin level (>3.5) were 1.6 times more likely to have good wound healing status as compared to malnourished patients (AHR � 1.56 (95% CI: 1.05-2.29)) ( Table 4).

Discussion
Wound healing is a complex and dynamic process that needs well-nutritional status for the rapid inflammatory phase, promote collagen production, enhance fibroblast proliferation, and fast granulation to increase wound tensile strength for good wound healing outcome. Preoperative well-nutritional status is a fundamental aspect for optimal wound healing which decreases hospital length of the stay, minimizes health care cost, and reduces postoperative infection and complication rate [19]. As the finding of this study, out of 310 adult patients who had undergone an abdominal surgical procedure, 209 patients were improved from surgical incision which gives 65.0% with 95% CI: 0.60-0.71 of overall good wound healing incidence rate. e finding was similar to studies done in India 63% [15], Brazil  67.8% [13], and Gaza Strip 65% [20], but lower compared to studies done in Korea 73% [21] and Italy 90% [22], the discrepancy might be due to difference of socioeconomic status, the magnitude of sample size, distribution of geographical area, and different sit of the incisional wound and mode of surgery (only elective or emergency or both elective and emergency surgery). In this study nutritional status was found to be significantly associated with wound healing outcomes. is result was in agreement with other studies done in India [14], Italy [22], India [15], and Korea [21].
is finding could be explained by the fact that the patients had a good nutritional status which enhances the growth hormone and collagen production that increase tensile strength and decrease risk factor of wound healing dalliance.
While observing the actual practice in Ethiopian health facilities, there are no nutrition screening services before undergoing abdominal surgery. is makes the outcome of abdominal surgery worse and a long time hospitalization hospital. is study shows nutrition screening before undergoing abdominal surgery is an important point to improve wound healing outcomes and shorting hospitalization.
is study does not consider the effect of postoperative hospital-acquired malnutrition during a hospital stay because of the difficulty to measure the postoperative nutritional status of patients. is current follow-up study did not follow up those patients once who had good wound healing outcomes and discharge even if the wound relapses and develops any sign of poor wound healing at home. In this study, the patient's dietary intake habit and immunity do not  Journal of Nutrition and Metabolism 5 include a predicted variable due to difficulty to measure. Despite limitations, this study provides vital baseline information on incidence rate and predictors of wound healing among adult patients who had undergone abdominal surgery at Bahir Dar City Public Hospitals, Northwest Ethiopia.

Conclusion
Nutritional status had a strong association with good wound healing outcomes. erefore, nutritional status screening should be done for all adult patients before undergoing abdominal surgery to improve wound healing outcomes and reduce hospital stays. Data Availability e datasets supporting the conclusions of this article are included in the article.

Ethical Approval
Ethical clearance was obtained from the Institutional Review Board, College of Medicine and Health Sciences, Bahir Dar University, Ethiopia. Permission letters were obtained from each Bahir Dar City Public Hospital's manager.

Consent
Written consent was obtained from the patient after providing information about the purpose of the study.

Conflicts of Interest
e authors declare that they have no conflicts of interest.

Authors' Contributions
NF, YA, and YM assisted in the conception of the study; developed the proposal; were involved in the method development, analysis, interpretation of the findings, and development of the manuscript. All the authors read, revised, and approved the final manuscript.