Session Information
Date: Tuesday, November 10, 2015
Title: Epidemiology and Public Health IV: Risk Factors and Comorbidities for SLE and Psoriatic Arthritis
Session Type: ACR Concurrent Abstract Session
Session Time: 4:30PM-6:00PM
Background/Purpose:
Infections are a significant cause of morbidity and mortality in SLE patients.
Recent studies show that lupus nephritis patients have more than two-fold
higher incidence of serious infections than the overall SLE population. We
investigated the burden of hospitalized infections and related mortality among
patients with SLE-related end-stage renal disease (ESRD).
Methods:
We
used the US Renal Data System, the national registry of ESRD patients, 1995-2008,
to identify adults ≥18 years with ESRD due to SLE as recorded by nephrologists
on the Medical Evidence Report. We ascertained age, sex, race/ethnicity, region,
comorbidities, prior insurance, and dialysis type at ESRD onset. For patients
with Medicare Parts A and B coverage beginning 90 days following ESRD onset, we
used linked claims to determine hospitalizations for infection from primary discharge
diagnosis ICD-9 codes. We calculated mortality due to infection, as documented
on the ESRD Death Notification Form, among patients with SLE-related ESRD
regardless of Medicare coverage. We calculated incidence rates (IR) of first hospitalization
for infection after ESRD onset, and mortality due to infection. We used multivariable
Cox proportional hazard regression to determine the hazard ratio (HR) of first
hospitalized infection and mortality from infection by race/ethnicity and sex,
adjusting for demographics, comorbidities, and dialysis type.
Results: We
identified 12,533 patients with SLE-related ESRD and 6,064 with linked Medicare
claims. The mean age for the linked cohort was 41.8 years (SD 16.5), 81% were
female, 52.4% Black, 42.3% White, and 4.2% Asian, and 15.2% were Hispanic. Mean
follow-up was 4.0 years (SD 3.3). The majority (84%) received hemodialysis. The
IR of first hospitalization for infection after ESRD onset was 25.9 per 100
person-years. In adjusted models, the risk was lower among males compared to
females (HR 0.83, 95% CI 0.76-0.91) and higher among Blacks (HR 1.16, 95% CI
1.11-1.27) and Native Americans (HR 1.40, 95% CI 1.04-1.88) compared to Whites.
The risk of infection was higher among patients receiving peritoneal dialysis
compared to hemodialysis (HR 1.19, 95% CI 1.07-1.32). Among all patients with
SLE-related ESRD, there were 4,428 deaths; 865 (19.5%) were from infection, the
majority from septicemia (79.9%). Infection-related mortality was 1.77 per 100
person-years, significantly higher among Blacks compared to Whites (HR 1.20,
95% CI 1.02-1.42), and not statistically different for other racial/ethnic
groups or by sex.
Conclusion:
In
this cohort of patients with SLE-related ESRD, we observed a high burden of
hospitalization for infection and related mortality with similar infection
rates to pre-ESRD lupus nephritis patients. Female, Black and Native American
patients were at increased risk of infection. Further studies are needed to
compare these rates to non-SLE patients with ESRD.
|
Table. Incidence Rates and Adjusted Hazard Ratios of First Hospitalized Infection* among patients with SLE-Related End-stage Renal Disease and Medicare Parts A and B |
||||
|
Events
|
Person-years
|
IR** (95% CI)
|
HR+ (95% CI)
|
|
|
Overall (N=6064) |
3496 |
13498.1 |
25.9 (25.1-26.7) |
— |
|
Sex
|
||||
|
Female |
2913 |
10762.3 |
27.1 (26.1-28.1) |
Ref. |
|
Male |
583 |
2735.8 |
21.3 (19.6-23.1) |
0.83 (0.76-0.91)
|
|
Race/Ethnicity
|
||||
|
White |
1344 |
5710.0 |
23.5 (22.3-24.8) |
Ref. |
|
Black |
1982 |
6964.9 |
28.4 (27.2-29.7) |
1.16 (1.11-1.27)
|
|
Asian |
123 |
694.3 |
17.7 (14.8-21.1) |
0.88 (0.72-1.07) |
|
Native American |
47 |
129.0 |
36.4 (27.4-48.5) |
1.40 (1.04-1.88)
|
|
Hispanic Ethnicity
|
||||
|
Hispanic |
531 |
2299.0 |
23.1 (21.2-25.1) |
1.01 (0.90-1.13) |
|
Non-Hispanic |
2965 |
11199.1 |
26.4 (25.5-27.4) |
Ref. |
|
*Primary discharge diagnosis with ICD-9 code for bacterial, viral, fungal or opportunistic infection (Schneeweiss et al. J Clin Epidemiol. 2007) **Incidence rate of first hospitalized infection per 100 person-years +Hazard ratios from Cox proportional hazard regression models adjusted for age group, sex, race/ethnicity, US region, insurance status prior to ESRD, baseline comorbidities including hypertension, smoking, diabetes, coronary artery disease, cerebrovascular disease, cancer, and COPD, renal replacement therapy, and calendar year |
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To cite this abstract in AMA style:
Feldman CH, Marty FM, Winkelmayer WC, Guan H, Franklin JM, Kim SC, Solomon DH, Costenbader KH. Rates of Hospitalization for Infection and Related Mortality By Race/Ethnicity and Sex Among Patients with End-Stage Renal Disease Due to Systemic Lupus Erythematosus [abstract]. Arthritis Rheumatol. 2015; 67 (suppl 10). https://acrabstracts.org/abstract/rates-of-hospitalization-for-infection-and-related-mortality-by-raceethnicity-and-sex-among-patients-with-end-stage-renal-disease-due-to-systemic-lupus-erythematosus/. Accessed .ACR Meeting Abstracts - https://acrabstracts.org/abstract/rates-of-hospitalization-for-infection-and-related-mortality-by-raceethnicity-and-sex-among-patients-with-end-stage-renal-disease-due-to-systemic-lupus-erythematosus/