Acute Kidney Injury Risk Factors For ICU Patients Following Cardiac Surgery: The Application of Joint Modeling.
BACKGROUND
Admission to the ICU (intensive care unit) is frequently complicated by early AKI (acute kidney injury). The development of AKI following cardiac surgery is particularly associated with increased mortality and morbidity. According to AKIN (acute kidney injury network) criteria, UO (urinary output) is a predictor for AKI.


OBJECTIVE
The goal of this study was to determine the effects of some AKI risk factors on AKI and also to investigate changes in UO as a predictor of AKI using joint modeling.


METHODS
In a retrospective study, 300 cardiac-operated patients, who had been admitted over a period of three years, were selected according to the consecutive sample selection method, using the ICU at Masih Daneshvari Hospital in Iran as a referral center. The random mixed effect model and the survival model were used to investigate UO changes and estimate the effect of UO and other risk factors on the hazard rate of AKI in a joint analysis.


RESULTS
AKI occurred in 38.0% of patients. A significant decrease of UO occurred more often in female and infected patients, as well as those with a low DBP (diastolic blood pressure). The survival model showed that the risk of AKI in females, older patients and patients with low DBP, lower UO and with infection was higher (P = 0.001). Using joint modeling, the association parameter between the risk of AKI and UO was estimated (-0.3, P = 0.002).


CONCLUSIONS
Where there is a relationship between two longitudinal and survival responses, joint modeling can estimate it.
Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, IR Iran.
Batoul
B
Khoundabi
Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, IR Iran.
Anoshirvan
A
Kazemnejad
Department of Epidemiology and Biostatistics, School of Public health , Isfahan University of Medical Sciences, Isfahan, IR Iran.
Marjan
M
Mansourian
Critical Care, Chronic Respiratory Disease Research Center (CRDRC), National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Masih Daneshvari Hospital, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran.
Seyed Mohammadreza
SM
Hashemian
Department of Biostatistics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, IR Iran.
Mehdi
M
Kazempoor Dizaji
Acute Kidney Injury; Cardiac Surgery; Joint Models; Risk Factor; Urinary Output