Title: Hospital-based prevalence and predictors of upper gastrointestinal bleeding in Northern
Uganda: A retrospective cross-sectional study
Version: 3 Date: 20 May 2025
Reviewer:  Anwar Ashraf Abouelnasr
Reviewer's report:
Dear Authors, please address the following points below
1)Study Design Limitations:
Retrospective Cross-Sectional Design: The study relies on retrospective data, which limits the
ability to establish causal relationships between the risk factors and UGIB. The use of a cross-
sectional design further restricts the ability to make inferences about the temporal relationship
between exposures and outcomes. This could have been improved by a prospective cohort design
to establish causality more effectively.
Selection Bias: The study relies on hospital-based data, which may not be representative of the
general population. Since the research only included patients admitted to healthcare facilities,
the true prevalence of UGIB in the broader community might be underrepresented, as mild or
self-resolving cases may not have been included.
2)Inconsistent Reporting of Risk Factors:
Missing Data: The study mentions challenges related to missing information, which could
influence the strength of the associations found between variables. Missing data on key variables
such as the use of medications (NSAIDs, steroids, anticoagulants) is a major limitation and could
have impacted the conclusions drawn about risk factors for UGIB. This issue should have been
addressed by improving data collection protocols.
Alcohol Use and Other Risk Factors: While alcohol use is identified as a key modifiable risk
factor, the study does not include detailed information on the frequency or quantity of alcohol
use. A more nuanced approach to understanding alcohol consumption (e.g., amount, duration,
binge drinking) could provide a better understanding of its role in UGIB.
Underreporting of Medications: The lack of documentation on NSAIDs, steroids, and
anticoagulants is a significant gap. The retrospective design and the lack of routine
documentation could have affected the validity of findings related to these common risk factors
for UGIB.
3)Outcome Measures and Analysis:
Non-Endoscopic Diagnosis: The study relies on clinical diagnoses of UGIB without endoscopic
confirmation. While this is understandable given the resource constraints of the study setting, the
absence of endoscopic procedures could result in misclassification bias. Further research could
benefit from exploring diagnostic tools or strengthening collaboration with referral centers to
improve diagnostic accuracy.
Treatment Outcomes: The study categorizes short-term outcomes (improved, died, referred),
but more detailed information on treatment regimens and outcomes, including complications or
interventions used, could have provided better insight into the management of UGIB in resource-
limited settings. A follow-up study tracking long-term outcomes would be valuable.
4)Sample Size and Generalizability:
Small Sample Size: While the sample size calculation suggests that the study has sufficient
power, the study is based on a relatively small number of patients from only five health facilities.
This limits the external validity and generalizability of the findings to larger populations or other
districts in Uganda or sub-Saharan Africa.
Sampling Bias in Facility Selection: The purposive sampling of only health facilities that provide
inpatient care for UGIB may have resulted in overrepresentation of more severe cases. This
could bias the results, especially since the findings may not reflect the true prevalence and factors
associated with UGIB in the broader population.
5)Potential Confounders and Interactions:
Interaction Between Risk Factors: The study highlights interactions between schistosomiasis
and alcohol use, suggesting the possibility of confounding factors. While multicollinearity
testing was performed, the study does not delve deeply into these interactions in the results
or discussion. Future studies could use more sophisticated statistical methods (e.g., stratified
analysis or mediation analysis) to explore the interplay between multiple risk factors.
6)Limited Scope on Diagnostic and Management Practices:
Diagnostic Tools: The study's reliance on clinical diagnoses in the absence of endoscopy is
an important limitation. It would be beneficial to explore the feasibility and cost-effectiveness
of implementing diagnostic tools like endoscopy in lower-level health facilities, which could
improve the accuracy of UGIB diagnoses.
Management Protocols: The study does not provide much detail on the management protocols
used for UGIB in these health facilities. An exploration of treatment practices, including
transfusion protocols, pharmacological interventions (e.g., proton pump inhibitors, antibiotics),
and their association with outcomes, could offer valuable insights.
7)Statistical Analysis Concerns:
Multicollinearity: While the study reports the use of variance inflation factors (VIF) to assess
multicollinearity, it does not address how this may have impacted the results. If collinearity is
an issue, the significance of certain predictors may have been distorted. Further explanation or
adjustments (such as variable selection techniques) could strengthen the analysis.
8)Clarity in the Presentation of Findings:
Clarity in Reporting: Some sections of the results and discussion may benefit from more clarity
in how findings are presented. For example, the relationship between schistosomiasis, liver
cirrhosis, and UGIB could be discussed in more depth, particularly regarding the role of alcohol
use in modifying these relationships.
Limitations in the Discussion: While the study mentions the limitations of a retrospective design,
a more in-depth discussion regarding potential biases (e.g., diagnostic misclassification, recall
bias) would be helpful. It also lacks a discussion on the external validity of the findings and the
implications for other regions with similar resource constraints.
Title: Hospital-based prevalence and predictors of upper gastrointestinal bleeding in Northern
Uganda: A retrospective cross-sectional study
Version: 3 Date: 20 May 2025
Reviewer:  Anwar Ashraf Abouelnasr
Reviewer's report:
Dear Authors, please address the following points below
1)Study Design Limitations:
Retrospective Cross-Sectional Design: The study relies on retrospective data, which limits the
ability to establish causal relationships between the risk factors and UGIB. The use of a cross-
sectional design further restricts the ability to make inferences about the temporal relationship
between exposures and outcomes. This could have been improved by a prospective cohort design
to establish causality more effectively.
Selection Bias: The study relies on hospital-based data, which may not be representative of the
general population. Since the research only included patients admitted to healthcare facilities,
the true prevalence of UGIB in the broader community might be underrepresented, as mild or
self-resolving cases may not have been included.
2)Inconsistent Reporting of Risk Factors:
Missing Data: The study mentions challenges related to missing information, which could
influence the strength of the associations found between variables. Missing data on key variables
such as the use of medications (NSAIDs, steroids, anticoagulants) is a major limitation and could
have impacted the conclusions drawn about risk factors for UGIB. This issue should have been
addressed by improving data collection protocols.
Alcohol Use and Other Risk Factors: While alcohol use is identified as a key modifiable risk
factor, the study does not include detailed information on the frequency or quantity of alcohol
use. A more nuanced approach to understanding alcohol consumption (e.g., amount, duration,
binge drinking) could provide a better understanding of its role in UGIB.
Underreporting of Medications: The lack of documentation on NSAIDs, steroids, and
anticoagulants is a significant gap. The retrospective design and the lack of routine
documentation could have affected the validity of findings related to these common risk factors
for UGIB.
3)Outcome Measures and Analysis:
Non-Endoscopic Diagnosis: The study relies on clinical diagnoses of UGIB without endoscopic
confirmation. While this is understandable given the resource constraints of the study setting, the
absence of endoscopic procedures could result in misclassification bias. Further research could
benefit from exploring diagnostic tools or strengthening collaboration with referral centers to
improve diagnostic accuracy.
Treatment Outcomes: The study categorizes short-term outcomes (improved, died, referred),
but more detailed information on treatment regimens and outcomes, including complications or
interventions used, could have provided better insight into the management of UGIB in resource-
limited settings. A follow-up study tracking long-term outcomes would be valuable.
4)Sample Size and Generalizability:
Small Sample Size: While the sample size calculation suggests that the study has sufficient
power, the study is based on a relatively small number of patients from only five health facilities.
This limits the external validity and generalizability of the findings to larger populations or other
districts in Uganda or sub-Saharan Africa.
Sampling Bias in Facility Selection: The purposive sampling of only health facilities that provide
inpatient care for UGIB may have resulted in overrepresentation of more severe cases. This
could bias the results, especially since the findings may not reflect the true prevalence and factors
associated with UGIB in the broader population.
5)Potential Confounders and Interactions:
Interaction Between Risk Factors: The study highlights interactions between schistosomiasis
and alcohol use, suggesting the possibility of confounding factors. While multicollinearity
testing was performed, the study does not delve deeply into these interactions in the results
or discussion. Future studies could use more sophisticated statistical methods (e.g., stratified
analysis or mediation analysis) to explore the interplay between multiple risk factors.
6)Limited Scope on Diagnostic and Management Practices:
Diagnostic Tools: The study's reliance on clinical diagnoses in the absence of endoscopy is
an important limitation. It would be beneficial to explore the feasibility and cost-effectiveness
of implementing diagnostic tools like endoscopy in lower-level health facilities, which could
improve the accuracy of UGIB diagnoses.
Management Protocols: The study does not provide much detail on the management protocols
used for UGIB in these health facilities. An exploration of treatment practices, including
transfusion protocols, pharmacological interventions (e.g., proton pump inhibitors, antibiotics),
and their association with outcomes, could offer valuable insights.
7)Statistical Analysis Concerns:
Multicollinearity: While the study reports the use of variance inflation factors (VIF) to assess
multicollinearity, it does not address how this may have impacted the results. If collinearity is
an issue, the significance of certain predictors may have been distorted. Further explanation or
adjustments (such as variable selection techniques) could strengthen the analysis.
8)Clarity in the Presentation of Findings:
Clarity in Reporting: Some sections of the results and discussion may benefit from more clarity
in how findings are presented. For example, the relationship between schistosomiasis, liver
cirrhosis, and UGIB could be discussed in more depth, particularly regarding the role of alcohol
use in modifying these relationships.
Limitations in the Discussion: While the study mentions the limitations of a retrospective design,
a more in-depth discussion regarding potential biases (e.g., diagnostic misclassification, recall
bias) would be helpful. It also lacks a discussion on the external validity of the findings and the
implications for other regions with similar resource constraints.
Please review this paper.
user
Title: Hospital-based prevalence and predictors of upper gastrointestinal bleeding in Northern
Uganda: A retrospective cross-sectional study
Version: 3 Date: 20 May 2025
Reviewer:  Anwar Ashraf Abouelnasr
Reviewer's report:
Dear Authors, please address the following points below
1)Study Design Limitations:
Retrospective Cross-Sectional Design: The study relies on retrospective data, which limits the
ability to establish causal relationships between the risk factors and UGIB. The use of a cross-
sectional design further restricts the ability to make inferences about the temporal relationship
between exposures and outcomes. This could have been improved by a prospective cohort design
to establish causality more effectively.
Selection Bias: The study relies on hospital-based data, which may not be representative of the
general population. Since the research only included patients admitted to healthcare facilities,
the true prevalence of UGIB in the broader community might be underrepresented, as mild or
self-resolving cases may not have been included.
2)Inconsistent Reporting of Risk Factors:
Missing Data: The study mentions challenges related to missing information, which could
influence the strength of the associations found between variables. Missing data on key variables
such as the use of medications (NSAIDs, steroids, anticoagulants) is a major limitation and could
have impacted the conclusions drawn about risk factors for UGIB. This issue should have been
addressed by improving data collection protocols.
Alcohol Use and Other Risk Factors: While alcohol use is identified as a key modifiable risk
factor, the study does not include detailed information on the frequency or quantity of alcohol
use. A more nuanced approach to understanding alcohol consumption (e.g., amount, duration,
binge drinking) could provide a better understanding of its role in UGIB.
Underreporting of Medications: The lack of documentation on NSAIDs, steroids, and
anticoagulants is a significant gap. The retrospective design and the lack of routine
documentation could have affected the validity of findings related to these common risk factors
for UGIB.
3)Outcome Measures and Analysis:
Non-Endoscopic Diagnosis: The study relies on clinical diagnoses of UGIB without endoscopic
confirmation. While this is understandable given the resource constraints of the study setting, the
absence of endoscopic procedures could result in misclassification bias. Further research could
benefit from exploring diagnostic tools or strengthening collaboration with referral centers to
improve diagnostic accuracy.
Treatment Outcomes: The study categorizes short-term outcomes (improved, died, referred),
but more detailed information on treatment regimens and outcomes, including complications or
interventions used, could have provided better insight into the management of UGIB in resource-
limited settings. A follow-up study tracking long-term outcomes would be valuable.
4)Sample Size and Generalizability:
Small Sample Size: While the sample size calculation suggests that the study has sufficient
power, the study is based on a relatively small number of patients from only five health facilities.
This limits the external validity and generalizability of the findings to larger populations or other
districts in Uganda or sub-Saharan Africa.
Sampling Bias in Facility Selection: The purposive sampling of only health facilities that provide
inpatient care for UGIB may have resulted in overrepresentation of more severe cases. This
could bias the results, especially since the findings may not reflect the true prevalence and factors
associated with UGIB in the broader population.
5)Potential Confounders and Interactions:
Interaction Between Risk Factors: The study highlights interactions between schistosomiasis
and alcohol use, suggesting the possibility of confounding factors. While multicollinearity
testing was performed, the study does not delve deeply into these interactions in the results
or discussion. Future studies could use more sophisticated statistical methods (e.g., stratified
analysis or mediation analysis) to explore the interplay between multiple risk factors.
6)Limited Scope on Diagnostic and Management Practices:
Diagnostic Tools: The study's reliance on clinical diagnoses in the absence of endoscopy is
an important limitation. It would be beneficial to explore the feasibility and cost-effectiveness
of implementing diagnostic tools like endoscopy in lower-level health facilities, which could
improve the accuracy of UGIB diagnoses.
Management Protocols: The study does not provide much detail on the management protocols
used for UGIB in these health facilities. An exploration of treatment practices, including
transfusion protocols, pharmacological interventions (e.g., proton pump inhibitors, antibiotics),
and their association with outcomes, could offer valuable insights.
7)Statistical Analysis Concerns:
Multicollinearity: While the study reports the use of variance inflation factors (VIF) to assess
multicollinearity, it does not address how this may have impacted the results. If collinearity is
an issue, the significance of certain predictors may have been distorted. Further explanation or
adjustments (such as variable selection techniques) could strengthen the analysis.
8)Clarity in the Presentation of Findings:
Clarity in Reporting: Some sections of the results and discussion may benefit from more clarity
in how findings are presented. For example, the relationship between schistosomiasis, liver
cirrhosis, and UGIB could be discussed in more depth, particularly regarding the role of alcohol
use in modifying these relationships.
Limitations in the Discussion: While the study mentions the limitations of a retrospective design,
a more in-depth discussion regarding potential biases (e.g., diagnostic misclassification, recall
bias) would be helpful. It also lacks a discussion on the external validity of the findings and the
implications for other regions with similar resource constraints.
assistant