Morbidity and Mortality Among Dialysis Patients After Treatment for Depression

Morbidity and Mortality among Dialysis Patients after Treating Depression

Objectives

Our investigation has two objectives:

1. To assess whether treatment and recovery from depression decreases adverse clinical
events in chronic hemodialysis patients. Significant morbidity is associated with
depression in dialysis patients, but subsequent impact on outcome after treatment of
depression has not been reported.

2. To examine the rates of recovery from depression over a 6-month and 12-month period
among prevalent dialysis patients. Rates of recovery among dialysis patients with
depression are unclear. The natural history of depression among dialysis patients may
help long-term management.

Plan and Methods

This project is a longitudinal prospective cohort study comprised of dialysis patients from
outpatient dialysis units in the Portland, Oregon metropolitan area. Patients must be aged
18 or older and have started dialysis at least 90 days prior to enrollment. Patients are
excluded if they are delirious, demented, cannot speak English, or have a prior psychiatric
diagnosis other than depression. Baseline data collection includes patient demographics,
etiology of renal disease, nutritional status, past medical and psychiatric history and
baseline health status. Social support and quality of life assessments are obtained from
direct interview. All patients are assessed for depression by the Beck Depression Index, a
depression scale particularly useful in those with chronic illness, and the Diagnostic
Interview Scale, a gold standard for depression assessment.

Those that are depressed will undergo pharmacologic treatment with an SSRI, if they agree,
and be reassessed at 2 and 6 months for improvement. Patients who do not respond are
referred for psychiatric therapy. The primary outcome of our study is the combined rate of
prespecified morbidity and mortality at 18 months between two groups: depressed subjects
agreeing to treatment and depressed subjects not agreeing to treatment. Prespecified
morbidities include rates of 1) cardiovascular and cerebrovascular events, 2) infections, 3)
vascular access complications, and 4) death. These were selected based on prior studies
suggesting that depression increases cardiovascular and cerebrovascular events, suppresses
the immune system, and up-regulates coagulation factors and platelet aggregation. , , , , ,
,

Chi-square tests and T-tests will be used to compare baseline variables among those who are
and are not depressed. A multivariable Cox proportional hazards model will compare survival
among groups, with adjustments for baseline variables. Calculations derived from the
Neyman-Pearson equation determined a sample size of 120 subjects.

Findings to date

We have enrolled 134 subjects to date, including 47 from the PVAMC, and 87 from outside
dialysis units. Twenty-percent of them have been depressed. (We need to enroll 120 depressed
patients.) No further results have been obtained this year. No further characteristics have
been analyzed to date. All adverse events have been reported, none were unexpected.

Significance

We hope to demonstrate a reduction in adverse clinical outcomes with treatment of
depression. If so, we would advocate that depression is a modifiable risk factor that
warrants therapy for well-being in dialysis patients.