Background
Survival of rheumatic diseases has been improved over time.1 Prognosis and causes of death are different between races (Hispanic and African-American SLE patients have worse prognosis than others).2
Objectives
To evaluate causes of hospitalization and death in Mexican patients with SLE or RA. Our secondary objective was to compare the mortality of two six-year periods (2001-2006 and 2007-2012).
Methods
In a 12-year period, we evaluate all non-elective hospitalizations with diagnoses of RA or SLE according to the diagnosis registered in our Hospital database (all diagnoses were classified according to the International Classification of Diseases – ICD). We extracted the cause of hospital discharge, sex, age, and demographic factors. We compared the first 6-year period (2001-2006) with a second period (2007-2012).
Results
We included 922 hospitalizations: 449 SLE (48.7%) and 473 (51.3%) RA patients; the twelve-year mortality was 12.5% (n=116). Mortality rate for hospitalizations in the first period (2001-2006) was 13.1 per 100 patient-years (100 PY), and 12.6/100 PY in the second period. The lowest mortality rate was in 2001 (4.4/100 PY) and the highest in 2009 (21.3/100 PY). Mortality among periods was 12.6% of admissions in winter, 10.5% in autumn, 17.0% in spring and 10.8% in summer. Infection was the most frequent cause of death in both RA (37.9%) and SLE (30.8%), followed by cardiovascular disease 15.2% for RA and 5.8% for SLE. Infections were more frequent and cardiovascular diseases more uncommon in 2007 to 2012 (Table 1).
Table 1.Characteristics of 922 hospitalizations of RA or SLE patients
SLE
RA
2007-12
2001-06
p-value
2007-12
2001-06
p-value
(n=257)
(n=192)
(n=290)
(n=183)
Mortality, n (%)
28 (10.9)
24 (12.5)
0.706
41 (14.1)
25 (13.7)
0.992
Women, n (%)
215 (83.7)
171 (89.1)
0.135
237 (81.7)
141 (77.0)
0.263
Age*
29.7 (13.0)
29.8 (12.4)
0.952
57.5 (17.1)
58.1 (16.1)
0.687
Spring, n (%)
58 (57.4)
43 (42.6)
0.755
95 (32.8)
45 (32.1)
0.203
Summer, n (%)
71 (56.8)
54 (43.2)
60 (56.6)
46 (43.4)
Autumn, n (%)
62 (53.9)
53 (46.1)
71 (62.3)
43 (37.7)
Winter, n (%)
66 (61.1)
42 (38.9)
64 (56.6)
49 (43.4)
Stroke, n (%)
1 (0.4)
0 (0%)
1.000
3 (1.0)
6 (3.3)
0.095
CV, n (%)
6 (2.3)
17 (8.9)
0.004
23 (7.9)
9 (4.9)
0.279
Infections, n (%)
52 (20.2)
25 (13.0)
0.06
65 (22.4)
37 (20.2)
0.652
Cancer, n (%)
1 (0.4)
4 (2.1)
0.169
7 (2.4)
5 (2.7)
1.000
DM2, n (%)
10 (3.9)
5 (2.6)
0.627
48 (16.6)
28 (15.3)
0.816
Systemic hypertension, n (%)
30 (11.7)
14 (7.3)
0.166
85 (29.3)
43 (23.5)
0.201
CRF, n (%)
42 (16.3)
32 (16.7)
1.000
17 (5.8)
6 (3.3)
0.292
*Mean (SD). CV: Cardiovascular diseases, DM2: Type 2 diabetes mellitus, CRF: Chronic renal failure.
Conclusions
Infections and cardiovascular diseases are the most frequent causes of death in Mexican patients with SLE or RA. Prevention of these morbidities should be a priority.
References
Borchers AT, Keen CL, Shoenfeld Y, Gershwin ME. Surviving the butterfly and the wolf: mortality trends in systemic lu...