Published in:
01-07-2004 | Correspondence
Looking at subgroups in an inhomogeneous population does not make these subgroups more homogeneous
Published in: Intensive Care Medicine | Issue 7/2004
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Sir: The paper from Dhainaut et al. published recently in Intensive Care Medicine [1] is one of several papers looking at subgroups of patients included in the Prowess trial (Drotrecogin alpha-activated—in the treatment of severe sepsis) [2]. The paper brings important additional information on the results of this trial in the population selected by the European Agency for the Evaluation of Medicinal Products (EMEA) for licensing the compound (Xigris): the patients with multiple-organ dysfunction. The difference in mortality between treated and placebo patients is significant in the most severe patients and very limited in the less severe ones. However, looking at subgroups of patients is dangerous. In particular, we must know if the patients are still comparable at randomization. Comparability of the patients in both arms is hopefully shown in the paper by Dhainaut et al. [1], both in patients with single-organ or multiple-organ failure. The data, which concern the underlying condition of the patients, are summarized on Table 1.|
Single-organ dysfunction
|
Multiple-organ dysfunction
|
|||||
|---|---|---|---|---|---|---|
|
Treated (%)
|
Placebo (%)
|
P-T diff (%)
|
Treated (%)
|
Placebo (%)
|
P-T diff (%)
|
|
|
Myocardial infraction
|
13
|
14.3
|
1.3
|
11.8
|
14.4
|
2.4
|
|
Congestive cardiomyopathy
|
8.8
|
7.4
|
−1.4
|
5.5
|
9.6
|
4.1
|
|
Diabetes
|
22.7
|
22.7
|
0
|
20.0
|
22.3
|
2.3
|
|
Pancreatitis
|
5.1
|
6.4
|
1.3
|
2.8
|
3.1
|
0.3
|
|
Liver diseases
|
2.8
|
2.0
|
−0.8
|
1.9
|
2.8
|
0.9
|
|
COPD
|
18.5
|
18.7
|
0.2
|
23.5
|
28.4
|
4.9
|
|
Cancer
|
14.8
|
14.8
|
0
|
17.8
|
20.1
|
2.3
|
|
Hypertension
|
37.0
|
32.5
|
−4.5
|
38.6
|
35.8
|
−2.8
|