Table 4

Predictors of a low adrenocortictrophic hormone response in multivariate analysis

Factor

Increase <250 nmol/l

Peak <500 nmol/l

OR (95% CI)

P

Validity

OR (95% CI)

P

Model 1a (n = 404)

Model 1b (n = 403)

Positive other local culture

na

2.40 (1.32–4.37)

0.004

<5%

Sepsis at admission

2.34 (1.13–4.84)

0.022

<5%

na

SOFA test day

1.11 (1.03–1.18)

0.003

50–80%

1.11 (1.01–1.21)

0.024

50–80%

Baseline cortisol (nmol/l)

1.001 (1.000–1.002)

0.045

50–80%

0.987 (0.985–0.990)

<0.0001

>95%

Platelets (× 10⁹/l)

0.998 (0.996–1.000)

0.031

50–80%

0.997 (0.994–1.000)

0.044

50–80%

Bicarbonate (mmol/l)

na

0.91 (0.86–0.97)

0.003

80–90%

Cardiac surgery

0.48 (0.26–0.86)

0.013

90–95%

na

Arterial pH

0.011 (0.001–0.185)

0.002

>95%

na

Model 2a (n = 330)

Model 2b (n = 332)

SOFA test day

na

1.19 (1.09–1.30)

<0.0001

90–95%

Heart rate (beats/min)

1.015 (1.003–1.028)

0.015

50–80%

na

Platelets (× 10⁹/l)

0.997 (0.995–0.999)

0.009

50–80%

na

Baseline cortisol (nmol/l)

na

0.986 (0.983–0.990)

<0.0001

>95%

Albumin (g/l)

0.93 (0.90–0.97)

0.001

90–95%

0.92 (0.87–0.97)

0.003

80–90%

Cardiac surgery

0.40 (0.20–0.79)

0.008

>95%

na

Arterial pH

0.002 (0.0001–0.048)

<0.0001

>95%

na

Models 1 and 2 included all univariate significant variables that were available in at least 95% and 75% of patients, respectively (see text). Validity was assessed by bootstrap analysis (see Materials and methods). Hosmer-Lemeshow tests: model 1a: χ² = 9.2, degrees of freedom (df) = 8, P = 0.32; model 1b: χ² = 4.4, df = 8, P = 0.82; model 2a: χ² = 13.2, df = 8, P = 0.11; and model 2b: χ² = 10.0, df = 8, P = 0.26. CI, confidence interval; na, not applicable; OR, odds ratio; SOFA, Sequential Organ Failure Assessment.

de Jong et al. Critical Care 2007 11:R61   doi:10.1186/cc5928