Background/Purpose:  Data from other large SLE cohorts have suggested improving survival among SLE patients in recent years with protective effects from antimalarial use and less favorable prognoses among males. We investigated whether a change in survival has occurred among patients with SLE in our large academic lupus center over the past 41 years.

Methods:  Our lupus registry contains data on 5,030 patients seen in our lupus center for potential SLE (ICD-9 billing code 710.0) since the 1960s.  For this study, we included 1,099 patients who had validated SLE per both treating rheumatologist and an SLE expert, ≥ 4/11 of the 1997 ACR Criteria for Classification of SLE, date of diagnosis on or after January 1, 1970, and > 2 visits to our center.  Data ascertained from the medical record included age at SLE diagnosis, validated history of lupus nephritis, clinical manifestations, serologies, hematology and renal laboratories, medication use and date of death. Individuals were followed for ten years, or until death or end of follow-up period (April 30, 2011). Kaplan Meier curves with log rank tests and multivariable Cox proportional hazards models, adjusted for age at diagnosis, race, sex, nephritis and hydroxychloroquine use, were used to estimate the risk of death over time, and to investigate potential predictors of mortality in our cohort.

Results:  The 1,009 SLE patients were divided into two periods at a point where each group contributed equal person-time.  Date ranges were January 1, 1970-August 31, 1993 (54,000 person-months) and September 1, 1993-April 30, 2011 (54,000 person-months). Clinical characteristics of the patients diagnosed in each period are compared in Table 1A. All patients were ANA positive and approximately 60% in both periods were anti-dsDNA positive. More SLE patients in the recent periods were non-White. They were also older at diagnosis and a higher proportion was prescribed hydroxychloroquine. Overall mean follow-up of all patients was 8.8 years (SD±2.4). There were 70 deaths in period 1; 28 deaths in period 2. Ten year survival was 84.5% in period 1 and 95.0% in period 2 (log rank test p=0.01). In multivariable Cox proportional hazards model, the hazard ratio (HR) for 10 year mortality was 0.47 (95% CI 0.29-0.75) for those diagnosed in the later period, compared to those in the earlier time period. Older age at diagnosis and male sex were associated with increased 10 year mortality (Table 1B). There was no significant association between hydroxychloroquine use, race or nephritis with survival over this time period among our subjects.

Conclusion:  Despite changes in patient demographics, survival of patients with immunologically-rich, validated SLE followed in our lupus center has improved over the past 41 years. This improved survival may be related to better management of comorbidities and new modalities of treatment.

Table 1A. Comparison of Clinical Characteristics of SLE Patients Diagnosed in Early vs. Late Periods
Demographics	Period 1 (1970-1993), n=451	Period 2 (1993-2011), n=558	p  value*
Mean Age at Diagnosis (SD)	29.4 (12.2)	36.0 (13.6)	<0.001
Male, (%)	30 (6.7)	53 (9.5)	0.11
White, (%)	283 (62.8)	226 (40.5)	<0.001
ANA Positive, (%)	451 (100)	558 (100)	0.50
Anti-dsDNA Positive, (%)	268 (59.4)	336 (60.2)	0.85
Lupus Nephritis, (%)	145 (32.2)	167 (29.9)	0.45
Hydroxychloroquine Use, (%)	338 (75.3)	483 (86.6)	<0.001
* t-tests and Fisher exact tests
Table 1B. Factors Associated with 10 Year Mortality **
	Hazard Ratio for Death (95% Confidence Interval)
SLE Diagnosis in Period 2 vs. Period 1	0.47 (0.29-0.75)
Increasing Age at Diagnosis, per year	1.05 (1.03-1.07)
Male Sex	2.36 (1.32-4.20)
**HR= Hazard Ratio Cox proportional hazards models adjusted for age at diagnosis, race (White, Black, Hispanic, Asian, other), sex, hydroxychloroquine use, lupus nephritis.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/changes-in-ten-year-survival-among-sle-patients-at-an-academic-center-in-north-america-1970-2011/