Background/Purpose:

Systemic Lupus Erythematosus (SLE) is a chronic auto-immune disease associated with a wide spectrum of clinical manifestations and increased mortality. The most recent data about incidence of SLE in England date back to 1999.

It has been suggested that the incidence of SLE and other auto-immune diseases has increased over time.

Our purpose was:

* To estimate the incidence of SLE in England from 1998 to 2010 and to describe the incidence rate distribution by demographic factors.

* To discuss the hypothesis that the incidence of SLE increased from 2001 to 2010.

Methods:

We investigated the incidence of SLE among individuals documented in the Clinical Practice Research Datalink (CPRD) and linked with the Hospital Episode Statistics (HES) database. CPRD is a database of anonymized longitudinal medical records from primary care from over 600 practices in the United Kingdom. HES is a database documenting all admissions to the National Health System hospitals in England that can be linked with CPRD since 1997. All individuals documented in GPRD and HES prior to October 1^st, 2010 and aged 18 years or older were retained in the analysis.

Patients with SLE were identified as individuals with at least one relevant diagnosis code in CPRD or HES (list of codes available upon request).

Incident cases were defined as patients with at least 12 months of registration in CPRD prior to the date of first diagnosis. Incidence rates were estimated each calendar year from January 1^st 1998 to October 1^st 2010.

Results:

The incidence rate for the 2001-2010 time period is 5.5 per 100,000 patient*years (table 1): this estimate is very close to the 1998-2000 estimate (5.6 per 100,000 patient*years) and falls within the 95% confidence interval of each calendar year point estimate from 2001 to 2010.

Table 1: Incidence rate estimates per calendar year

Calendar year	Population exposed (patient*years)	Incident cases	Incidence rate (per 100,000 patient*years)
1998-2000	4,213,018	237	5.6 [4.9;6.3]
2001	1,504,620	83	5.1 [4.3;6.7]
2002	1,585,560	89	5.6 [4.4;6.8]
2003	1,639,386	87	5.3 [4.2;6.4]
2004	1,682,720	82	4.9 [3.8;5.9]
2005	1,720,965	88	5.1 [4.0;6.2]
2006	1,768,140	101	5.7 [4.6;6.8]
2007	1,812,779	109	6.0 [4.9;7.1]
2008	1,850,292	111	6.0 [4.9;7.1]
2009	1,859,559	93	5.0 [4.0;6.0]
2010 (through September 30)	1,359,960	79	5.8 [4.5;7.1]
2001-2010	16,784,884	922	5.5 [5.1;5.8]

Incidence rate is higher among women than men: 9.4 versus 1.5 per 100,000 patient*years. It reaches a maximum between 45 and 54 years of age in women (12.2 per 100,000 patient*years) while it keeps growing slightly with age in men; 25%(294) of the incident cases were documented in the HES database only.

Conclusion:

These incidence rates of SLE in England from 1998 to 2010 are consistent with prior estimates and with estimates in other western countries.

We did not observe any significant change in the incidence of SLE in England from 2001 to 2010.

---

« Back to 2012 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/incidence-of-systemic-lupus-erythematosus-in-england-1998-2010/