Prevalence of Psychiatric Diagnosis in Hospitalized Patients on Dialysis

Patients with end-stage renal disease (ESRD) may experience depression, anxiety, organic psychiatric disorders, dementia, disorders related to alcohol or drugs, or schizophrenic disorders, among others. Patients on maintenance dialysis commonly experience psychiatric illness, however, it is difficult to determine the true prevalence in that patient population, creating the possibility that psychiatric disorders in patients with ESRD may be under-recognized in research and in clinical care.

Data on the prevalence vary; a systemic review and meta-analysis found prevalence estimates for depression in patients on dialysis ranged from 1.4% to 94.9%, with a summary prevalence estimate of 39.3% when depression was assessed by questionnaire and 22.8% when assessed by interview. Data on psychiatric illnesses in pediatric patients with ESRD are limited by small study sizes, but, as with adult patients, pediatric patients with ESRD appear to have higher rates of depression compared with healthy controls.

There is an association between the presence of depression or anxiety and lower quality of life in adults and pediatric patients with kidney disease. There is also an association between depression in adults with ESRD and lower treatment adherence, more frequent hospitalizations, and increased mortality. Among pediatric patients on dialysis, there is an association between increased disease duration and hospitalizations.

It is unknown how common psychiatric illnesses are among hospitalized patients with ESRD on dialysis; there are few data on the associations of those illnesses on outcomes in that patient population. Researchers, led by Paul L. Kimmel, MD, conducted a study designed to determine the prevalence of hospitalizations with psychiatric diagnoses within a year of initiation of treatment for ESRD in adults and pediatric patients who started treatment from 1996 to 2013. The researchers also sought to examine the associations between hospitalizations with psychiatric diagnoses and mortality in adult patients treated with dialysis. Results were reported in the Clinical Journal of the American Society of Nephrology [2019;14(9):1363-1371].

The study cohort included 9196 pediatric patients (0-21 years of age), 398,418 adult patients (22-64 years of age), and 626,344 elderly adult patients (≥65 years of age). Among the pediatric patients, 64% had a first-year hospitalization; of those, 48% had no psychiatric diagnoses, 1% had a primary psychiatric diagnosis, and 15% had a secondary psychiatric diagnosis. Among the adult patients, 66% had a first-year hospitalization; the percentages of no, primary, and secondary psychiatric diagnoses were 39%, 2%, and 25%, respectively. Among the elderly adult patients, 72% had a first-year hospitalization; the percentages for no, primary, and secondary psychiatric diagnoses were 51%, 2%, and 19%, respectively.

In the pediatric population hospitalized with a psychiatric diagnosis, the most common diagnosis was depression/affective disorders (n=67 patients; 4%). The most common psychiatric diagnoses among adults was depression/affective disorders (n=2907 patients; 3%), alcohol-related disorders (n=1142; 1%), and drug disorders (n=1041; 1%). The top primary psychiatric diagnoses among the elderly adults hospitalized were organic disorders/dementias (n=3680 patients; 3%), depression/affective disorders (n=1825 patients; 1%), and drug disorders (n=1205; 1%).

Over time, the percentage of patients hospitalized with psychiatric diagnoses increased, from 9% in 1996-1998 to 26% in 2011-2013 for pediatric patients, from 19% to 40% for adults, and from 17% to 39% for elderly adults. Women were more likely than men to have hospitalizations with psychiatric diagnoses: 17% versus 16% in pediatric patients; 29% versus 26% in adults; and 25% versus 21% in elderly adults. Patients with dual eligibility (Medicare and Medicaid) were more likely to have hospitalizations with psychiatric diagnoses compared with those without dual eligibility (17% vs 10% in pediatric patients; 30% vs 22% in adults; and 28% vs 21% in elderly adults).

Nearly the entire increase in hospitalizations with psychiatric diagnoses was due to secondary diagnoses. This may be due, in part, to the increased number of secondary codes allowed in Medicare Part A claims from nine in 2009 to 25 in 2010.

Among the pediatric patients, the percentages with anxiety/personality disorders as secondary diagnoses remained relatively stable at 13% in 1996-1998 and 16% in 2008-2010, but increased to 24% in 2011-2013. The changes in percentages were similar among adults and elderly adults: percentages of adults and elderly adults with anxiety/personality disorders as secondary diagnoses were stable at 9% to 12% and 7% to 10%, respectively, between 1996-1998 and 2008-2010, but increased to 24% and 20%, respectively, in 2011-2013.

Analyses of the association between hospitalizations with psychiatric diagnoses and death were limited to a subset of adults treated with dialysis and ever hospitalized during the first year of ESRD. The overall mortality rate was 242.4 deaths per 1000 person-years (95% confidence interval [CI], 241.6-243.2). In patients hospitalized without a psychiatric diagnosis, the mortality rate was 237.2 (95% CI, 236.2-238.2). In hospitalized patients with a secondary psychiatric diagnosis, the mortality rate was 252.1(95% CI, 250.5-253.6). In those with primary psychiatric diagnoses, the morality rate was 275.3 (95% CI, 269.4-281.3).

Following adjustment for demographic characteristics, residential area, dual eligibility, Charlson score, and comorbid conditions at time of dialysis initiation, compared with patients hospitalized without a psychiatric diagnosis, the hazard ratios of death were 1.29 (95% CI, 1.26-1.32) in all adults hospitalized with primary psychiatric diagnoses, and 1.11 (95% CI, 1.10-1.12) in all adults hospitalized with secondary psychiatric diagnoses. Findings were similar for associations between hospitalizations with psychiatric diagnoses and first year death.

There were some limitations to the findings cited by the authors, including relying on clinical diagnosis for the primary and secondary hospitalization diagnoses that are delineated by codes that may have missed diagnoses in patients treated with dialysis.

In summary, the researchers said, “We conclude that hospitalizations with psychiatric diagnoses are common in the United States adult and pediatric patients on dialysis, and such hospitalizations are associated with higher mortality in adults. This study likely underestimates the true burden of these conditions within the dialysis population. Further research is needed to understand their prevalence in cases where the conditions may not result in (or be coded for) hospitalization. The findings suggest clinicians who care for hospitalized dialysis patients should be aware of and prepared to manage psychiatric disorders and associated negative outcomes within these populations.”

Takeaway Points

  1. Researchers conducted a study to examine the prevalence of hospitalizations with psychiatric diagnoses within a year of initiation of treatment for end-stage renal disease in adult and pediatric patients.
  2. The prevalence of hospitalizations with psychiatric diagnoses increased over time across groups, primarily from secondary diagnoses; hospitalizations with psychiatric diagnoses are common in both adult and pediatric patient populations in the United States.
  3. Hazard ratios of death from all causes were higher in all adults on dialysis hospitalized with primary or secondary psychiatric diagnoses compared with those hospitalized without psychiatric diagnoses.