Modeling for Prediction of Mortality Based on past Medical History in Hospitalized COVID-19 Patients: A Secondary Analysis
Related Experiment Video
Updated: Jun 21, 2025

Establishing a Competing Risk Regression Nomogram Model for Survival Data
Published on: October 23, 2020
Seyyed Amir Yasin Ahmadi1, Yeganeh Karimi2, Arash Abdollahi3
1Preventive Medicine and Public Health Research Center Psychosocial Health Research Institute Iran University of Medical Sciences, Tehran, Iran.
Insights
Identifying past medical history is crucial for predicting COVID-19 mortality in Iranian patients. A history of infectious diseases significantly increases mortality risk, highlighting the need for targeted interventions.
Area of Science:
- Medical research
- Public health
- Epidemiology
Background:
- COVID-19 remains a concern for susceptible individuals post-emergency.
- Identifying risk factors for COVID-19 mortality is essential for targeted interventions.
Purpose of the Study:
- To develop a predictive model for COVID-19 mortality in Iranian patients.
- To identify at-risk groups based on past medical history (PMHx) and other factors.
Main Methods:
- Secondary analysis of hospitalized COVID-19 adult patients' data.
- Logistic regression used to predict mortality based on PMHx (ICD-10 codes) and covariates (e.g., ICU admission).
- Calculation of population attributable fraction (PAF) and odds ratios (OR) with 95% confidence intervals (CI).
Main Results:
- Overall mortality rate was 19.68% among 8879 patients.
- History of infectious and parasitic diseases showed the highest association with mortality (OR = 5.72).
- Cardiovascular system diseases had the greatest population attributable fraction (20.46%).
- Logistic regression identified infectious disease history as a significant predictor (OR = 3.089), aside from ICU admission and age.
- The model achieved good performance (Area Under Curve = 0.875).
Conclusions:
- A significant portion of COVID-19 mortality is linked to underlying conditions, particularly cardiovascular diseases.
- History of infectious diseases is a key predictor of mortality in hospitalized COVID-19 patients.
- Further research is needed for policy development to reduce COVID-19 mortality in vulnerable populations.
Introduction:
Although COVID-19 is not currently a public health emergency, it will affect susceptible individuals in the post-COVID-19 era. Hence, the present study aimed to develop a model for Iranian patients to identify at-risk groups based on past medical history (PMHx) and some other factors affecting the death of patients hospitalized with COVID-19.
Methods:
A secondary study was conducted with the existing data of hospitalized COVID-19 adult patients in the hospitals covered by Iran University of Medical Sciences. PMHx was extracted from the registered ICD-10 codes. Stepwise logistic regression was used to predict mortality by PMHx and background covariates such as intensive care unit (ICU) admission. Crude population attributable fraction (PAF) as well as crude and adjusted odds ratio (OR) with 95% confidence interval (CI) were reported.
Results:
A total of 8879 patients were selected with 19.68% mortality. Infectious and parasitic diseases' history showed the greatest association (OR = 5.72, 95% CI: 4.20, 7.82), while the greatest PAF was for cardiovascular system diseases (20.46%). According to logistic regression modeling, the largest effect, other than ICU admission and age, was for history of infectious and parasitic diseases (OR = 3.089, 95% CI: 2.13, 4.47). A good performance was achieved (area under curve = 0.875).
Conclusion:
Considering the prevalence of underlying diseases, many mortality cases of COVID-19 are attributable to the history of cardiovascular disease. Future studies are needed for policy making regarding reduction of COVID-19 mortality in susceptible groups in the post-COVID-19 era.
Related Concept Videos
Comparing the Survival Analysis of Two or More Groups
Cancer Survival Analysis
Kaplan-Meier Approach
Assumptions of Survival Analysis
Actuarial Approach
Consider the example of a high-risk surgical procedure with significant early-stage mortality. A two-year clinical study is conducted,...
Steps in Outbreak Investigation

