Table 2

Performances of the PAWS, PEWS and Bedside PEWS scores on the derivation sample on the first 24 hours, first 36 hours, first 48 hours and first 6 days

 Total scores analysed (complete and imputed with ‘default to normal’ method) Scores AUC (95% CI) Probability threshold (%)* Specificity (%) PPV (%) NPV (%) ≤24 hours (n=4693 observations; call to physician=494 (11%) observations) PAWS† 0.87 (0.85 to 0.89) 5.9 49 17 98 PEWS‡ 0.87 (0.86 to 0.89) 6.0 48 17 98 Bedside PEWS§ 0.87 (0.85 to 0.89) 5.2 48 16 98 ≤36 hours (n=5892 observations; call to physician=559 (9%) observations) PAWS† 0.90 (0.88 to 0.91) 7.3 64 20 98 PEWS‡ 0.89 (0.88 to 0.91) 6.7 55 17 98 Bedside PEWS§ 0.89 (0.87 to 0.91) 6.2 58 17 98 ≤48 hours (n=7196 observations; call to physician=629 (9%) observations) PAWS† 0.91 (0.90 to 0.92) 7.5 69 22 99 PEWS‡ 0.91 (0.89 to 0.92) 7.4 71 23 99 Bedside PEWS§ 0.91 (0.89 to 0.92) 6.7 70 21 99 ≤6 day (n=10 152 observations; call to physician=749 (7%) observations) PAWS† 0.91 (0.90 to 0.92) 7.1 77 23 99 PEWS‡ 0.91 (0.90 to 0.92) 7.1 76 23 99 Bedside PEWS§ 0.91 (0.90 to 0.92) 6.1 75 21 99
• If PAWS at admission=3, time=48 hours, PAWS (H48)=4.

• Predictive equation for call to physician: Logit=−2.867+0.315×(4)−0.072×(3)−0.016×(48)=−2.591.

• Probability of call to physician=1/(1+exp(−Logit)=7.0%.

• This probability is <7.5% (probability threshold for PAWS from admission to 48 hours): so nurse must not call physician.

• *Probability threshold maximising specificity for sensitivity fixed at 90%: probability computed from the general linear mixed model included the following effects: the score at time t, the score at admission and the time t.

• †Predictive equation for call to physician: Logit=−2.867+0.315×(score at the time t)−0.072×(score at admission)−0.016×(time t); probability of call to physician=1/(1+exp(−Logit)).

• ‡Predictive equation for call to physician: Logit=−2.630+0.448×(score at the time t)−0.101×(score at admission)−0.017×(time t); probability of call to physician=1/(1+exp(−Logit)).

• §Predictive equation for call to physician: Logit=−3.033+0.263×(score at the time t)−0.058×(score at admission)−0.015×(time t); probability of call to physician=1/(1+exp(−Logit)).

• AUC, area under the receiver-operating curve; Bedside PEWS, Bedside Paediatric Early Warning System; NPV, negative predictive value; PAWS, Paediatric Advanced Warning Score; PEWS, Paediatric Early Warning Score; PPV, positive predictive value.