Depression Impairs Level of Functioning in Chronic Kidney Disease Inpatients: A Case-Control Study

Objectives To evaluate the difference in demographics and clinical correlates during hospitalization for chronic kidney disease (CKD) between patients with depression and those without depression, and its impact on the severity of illness and in-hospital mortality. Methods We conducted a case-control study and included 2,296 adult inpatients (age ≥18 years) with a primary discharge diagnosis of CKD using the nationwide inpatient sample (NIS). We used propensity score matching to extract the cases i.e., CKD inpatients with depression (N = 1,264) and the controls i.e. CKD inpatients without depression (N = 1,032). The matching was done based on demographic characteristics of age at admission, sex, race, and median household income. Our outcomes of interest are the severity of illness and all-cause in-hospital mortality. All patient refined drg (APR-DRG) are allocated using health information systems software by the NIS and the severity of illness within each base APR-DRG was classified into minor, moderate, or major loss of body functions. Binomial logistic regression analysis was conducted to find the odds ratio (OR) of association for major loss of function in CKD inpatients with depression, and this model was adjusted for potential confounders of congestive heart failure (CHF), coronary artery disease (CAD), diabetes, hypertension, obesity, and tobacco abuse, and utilization of hemodialysis. Results A higher proportion of CKD inpatients with depression had a statistically significant higher prevalence of major loss of function (49.8% vs. 40.3% in non-depressed). There was a statistically significant difference with higher utilization of hemodialysis in CKD inpatients with depression (76.2% vs. 70.7% in non-depressed). The all-cause in-hospital mortality rate was lower in CKD inpatients with depression (2.1% vs. 3.5% in non-depressed). After controlling the logistic regression model for potential comorbidities and utilization of hemodialysis, depression was associated with increased odds (OR 1.46; 95% CI 1.227 - 1.734) for major loss of function versus in non-depressed CKD inpatients Conclusion Comorbid depression increases the likelihood of major loss of functioning in CKD inpatients by 46%. Treating depression can allow patients to better cope emotionally and physically with CKD and other comorbidities and significantly improve the patient's quality of life (QoL) and health outcome.