Survival Analysis of Patients with Brain Stroke in the Presence of Competing Risks: A Weibull Parametric Model

Solmaz Norouzi; Ramazan Fallah; Ahmad Pourdarvish; Seyed Morteza Shamshirgaran; Farshid Farzipoor; Mohammad Asghari Jafarabadi

doi:10.18502/jbe.v7i3.7295

Solmaz Norouzi Department of Statistics and Epidemiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
Ramazan Fallah Department of Statistics and Epidemiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
Ahmad Pourdarvish Department of Statistics, University of Mazandaran, Babolsar, Iran.
Seyed Morteza Shamshirgaran Department of Statistics and Epidemiology, School of Health Sciences, University of Neyshabur, Neyshabur, Iran.
Farshid Farzipoor Department of Health Education and Promotion, School of Health, Tabriz University of Medical Sciences, Tabriz, Iran.
Mohammad Asghari Jafarabadi Department of Statistics and Epidemiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.

DOI: https://doi.org/10.18502/jbe.v7i3.7295

Keywords: Stroke; Risk factors; Survival analysis; Competing risk; Weibull Model

Abstract

Introduction: This study aimed to assess the association between the survival of patients and outcomes in Brain Stroke (BS) in the presence of competing risks utilizing a Weibull parametric model.

Methods: In this longitudinal study, 332 patients with BS were attended from Imam Khomeini Hospital in Ardabil, Iran. The stroke was diagnosed according to the medical history, current symptoms, and brain imaging during June 2008 and 2018. The survival of the patients, as the primary outcome, was modeled utilizing the best-chosen Weibull model in the presence of competing risks, including stroke and other factors (heart disease, blood pressure, etc.).

Results: Older age at diagnosis (59-68 years: hazard ratio [HR]=2.27; 90% confidence interval [CI]: 1.65 to 3.12; 69-75 years: HR=4.79; 95% CI: 3.56 to 6.44; ≥76 years: HR, 4.92; 95% CI: 3.55 to 6.80), being a male (HR, 1.39; 95% CI: 1.11 to 1.75), being unemployed (HR, 1.44; 95% CI: 1.39 to 1.82), having heart disease (HR, 1.68; 95% CI: 1.38 to 2.06), and hemorrhagic stroke (HR, 2.21; 95% CI: 1.378to 2.75) were directly related to death from BS. Older age at diagnosis (59-68 years: HR, 18.01; 90% CI, 5.33 to 64.92; 75-69 years: HR, 18.56; 95% CI: 6.97 to 86.57; ≥76 years: HR, 28.90; 95% CI: 15.77 to 218.49), and urban residence (HR, 0.46; 90% CI, 0.28 to 0.77) were directly related to death from other causes.

Conclusion: The recognition of the influential factors on the mortality of BS patients can allow increasing their survival.