1. Prevalence and Economic Impact of Depression Among Discharged Patients with Cardiac Events
Landon Marshall, Pharm.D., Matt Hill, Pharm.D., Jim Wilson, Pharm.D., Ph.D. Health Outcomes and Pharmacy Practice, College of Pharmacy, The University of Texas at Austin
Background
Methods
Results
Figure 1. Cohort Selection
Figure 2. Prevalence of Depression by Cardiac Condition at Discharge
Previous studies have shown that depression increases the risk of cardiovascular events.
The effect of selective serotonin reuptake inhibitors (SSRIs) on cardiovascular outcomes remains controversial. The use of tricycle antidepressants is associated with increased cardiovascular risk, but the clinical effect of SSRIs on cardiovascular outcomes remains unclear. Studies have provided conflicting evidence in terms of overall frequency and prognosis of cardiac events in depressed patients taking SSRIs.
Due to a favorable safety profile, SSRIs are commonly prescribed in the United States, and the American Psychiatric Association (APA) recommends them as first-line pharmacologic treatment for depression.
Analyzing the characteristics of hospitalization in patients with comorbid cardiac conditions and depression may provide a better understanding of the association between cardiac conditions and comorbid depression.
All hospitalizations between
January 1, 2013 and December 31, 2013
N = 7,119,563
Cardiac Condition with no Depression
n = 375,652
Cardiac Condition with Depression
(ICD-9-CM 311.xx, 296.2x, and 296.3x)
n = 40,119
All hospitalizations with a cardiac condition*
(ICD-9-CM 410.xx, 435.xx,
427.xx, and 426.xx)
n = 415,771
Objectives
To determine the prevalence of comorbid depression among hospitalized patients with cardiac events.
To determine the economic impact of comorbid depression among hospitalized patients with cardiac events.
Despite a large difference in the sample size of subgroups, prevalence rates of depression were similar.
Conclusions
The overall prevalence of depression in patients discharged with cardiac events was 9.7%. The incremental cost effectiveness ratio was -$2,094/hospital day for cardiac patients with depression. This finding suggests that cardiac patients with depression may utilize less hospital resources despite a greater length of stay, on average. Although the prevalence rates of depression were similar between subgroups, it is possible any large difference in cost could have been masked.
Due to baseline differences in gender, it would be useful to more-closely examine the economic impact of gender differences in cardiac patients with depression.
Methods
*Cardiac conditions of interest include: Myocardial Infarction (ICD-9 CM 410.xx), Stroke (ICD-9 CM 435.xx), or Arrhythmia (ICD-9 CM 427.xx and 426.xx)
A retrospective, discharge-level cohort analysis was conducted using the 2013 Nationwide Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP) dataset from the Agency of Healthcare Research and Quality (AHRQ).
All hospital discharges with a primary or secondary diagnosis of Myocardial Infarction (ICD-9 CM 410.xx), Stroke (ICD-9 CM 435.xx), or Arrhythmia (ICD-9 CM 427.xx and 426.xx) were identified. Two cohorts were defined based on the presence or absence of depression (ICD-9 CM 311.xx, 296.2x, and 296.3x). See figure 1 for cohort selection.
Study Measures
Primary outcomes:
Prevalence of comorbid depression (ICD-9 CM 311.xx, 296.2x, and 296.3x) among patients discharged with Myocardial Infarction (ICD-9 CM 410.xx), Stroke (ICD-9 CM 435.xx), or Arrhythmia (ICD-9 CM 427.xx and 426.xx)
Economic impact of comorbid depression in patients discharged with cardiac events. NIS 2013 cost-to-charge ratios were used to convert charges to costs.
Independent variables and covariates
Age
Gender
Death
Length of Stay
Chronic Comorbid Conditions
Descriptive statistics, t tests, and chi square tests were conducted to compare baseline characteristics. Regression models were employed for cost comparisons between cohorts. An incremental cost effectiveness ratio (ICER) was calculated for the cost per additional hospital day and was calculated by dividing the difference in cost between groups by the difference in length of stay between groups.
Results
Table 1. Discharge Characteristics by Cohort
Cardiac Event with No Depression n = 375,652
Cardiac Event with Depression n = 40,119
Mean age, years (SD)
69.85 (15.45)
69.17 (14.46)
Gender (% Female)
47.56
62.14
LOS, days (SD)
3.98 (5.19)
4.36 (5.88)
Total Cost in Dollars per Discharge (SD)
12,235 (17,854)
11,439 (13,763)
Mean number of chronic conditions (SD)
6.52 (2.88)
8.77 (2.97)
Payer type
Medicare (%)
66.85
69.55
Medicaid (%)
6.09
7.23
Private (%)
20.29
17.24
Other (%)
6.77
5.98
LOS = length of stay; SD = standard deviation
Limitations
The findings from this study only represent patients with cardiac events and do not necessarily reflect all patients with cardiac disease.
This study only includes hospitalized patients and may overestimate the prevalence of comorbid depression in patients with cardiac disease.
Dataset was limited to diagnosis at discharge and does not necessarily reflect SSRI usage.
Disclosure
The study was self-funded. The authors report no conflicts of interest relevant to this poster.
Discharge characteristics were similar between the two groups for age, length of stay, cost per discharge, and number of chronic comorbidities. The two groups were also similar when broken down by payer type.
The percentage of female patients was much greater in cardiac patients with depression vs cardiac patients without depression (62% vs. 48%). Overall, the percentage of female patients was 48.95%.
The incremental cost effectiveness ratio was -$2,094/hospital day for patients with depression.
References
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Musselman DL, Evans DL, Nemeroff CB. “The relationship of depression to cardiovascular disease: epidemiology, biology, and treatment.” Arch Gen Psychiatry. 1998;55:580–592.
Scherrer, Jeffrey F., et al. "Antidepressant drug compliance: reduced risk of MI and mortality in depressed patients." The American journal of medicine124.4 (2011):
William H. Sauer, Jesse A. Berlin and Stephen E. Kimmel. “Selective Serotonin Reuptake Inhibitors and Myocardial Infarction.” Circulation. 2001;104: doi:0.1161/hc
Coupland, Carol, et al. "Antidepressant use and risk of cardiovascular outcomes in people aged 20 to 64: cohort study using primary care database." bmj 352 (2016): i1350.
Hare et al. “Depression and cardiovascular disease: a clinical review.” European Heart Journal Jun 2014, 35 (21) ; DOI: /eurheartj/eht462