The finding:
The study assessed the prevalence of hospitalizations in ESRD patients (adult and pediatric) with psychiatric diagnoses and all-cause death after discharge within 1 year of treatment initiation. They included patients from 1996 to 2013 using the US Renal Data System (USRDS). They showed 27%, 21% and 16% of adults, elderly adults and pediatric patients respectively had hospitalizations with psychiatric diagnoses. Depression/affective disorders in adult and pediatric patients and dementias/organic disorders in elderly patients were the most common primary psychiatric diagnosis. In all adults, primary and secondary psychiatric diagnoses during hospitalization within 1 year of dialysis initiation were associated with 29% and 11% higher hazards of death, respectively.

Strength and weaknesses:

Strengths-
They examined hospitalizations involving a wide spectrum of psychiatric illnesses, including depression, anxiety, substance abuse disorders, psychotic disorders, and dementia. Large national sample, inclusion of pediatric patients, and long period of study that led to examination of secular trends in hospitalizations involving psychiatric illness.

Weaknesses-
They used an observational registry so causality cannot be inferred. There may be residual confounding and bias. The diagnoses relied just on ICD-9-CM codes which is dependent on the accuracy of clinical diagnosis, documentation, and administrative coding practices. There is also some variability in validity of ICD-9 coding for psychiatric illness. Missed psychiatric diagnoses may occur due to overlap with medical issues like uremia. There are limitations interpreting pediatric data due to low number of patients and the high geographic variance in treatments available.

Relevance:
It is well established that psychiatric co-morbidity in patients with ESRD on HD is high and associated with poor quality of life and prognosis. This is the first study looking at how common psychiatric illnesses are in the hospitalized ESRD HD population and their associations with outcomes. The study alerts clinicians about the diversity in psychiatric conditions that commonly afflict their patients of different ages. A third of ESRD patients on HD have depressive symptoms so it is not surprising that the study showed depression/affective disorders being the most common diagnosis in adults. In both adults and elderly adults, hospitalizations with psychiatric diagnoses within a year of ESRD initiation were associated with higher mortality after adjusting for various confounders. This may be due to barriers to adherence, effect on immunologic and stress responses and nutritional status in ESRD, overwhelming the resources available for care in conventional outpatient treatment settings, reducing quality of care and survival which were aptly noted by the study authors. It should be noted that the study analysis underestimates the true prevalence of mental illness in this population as it is only limited to patients with severe illness requiring hospitalization. The study highlights the substantial growing burden of psychiatric illness among patients with ESRD. As our nephrology colleagues get more involved to successfully manage psychiatric illness in this patient population given the increased awareness, more engagement from CL psychiatrists will be sought to assist. Given the current care for these patients is fragmented and siloed, there is a case for establishing more collaborative/integrated models of care with nephrologists. CL psychiatrists should be aware and prepared to manage psychiatric disorders in hospitalized ESRD HD patients given the associated negative outcomes within these populations.

Type of study: Retrospective cohort study