Table 3.

Accuracy of the Modified Early Warning Score Versus the Rothman Index to Predict 24-Hour Mortality (N = 1,794,910)

Cut Points	MEWS = 4	RI = 16*	MEWS = 4	RI = 30†
Likelihood ratio, positive	7.8	16.9	7.8‡	7.9‡
Likelihood ratio, negative	0.54‡	0.53‡	0.54	0.26
Sensitivity	49.8%	48.9%	49.8%	76.8%
Specificity	93.6%	97.1%	93.6%	90.4%
Positive predictive value	5.2%	10.6%	5.2%	5.3%
Negative predictive value	99.6%	99.6%	99.6%	99.8%

NOTE: An alarm at MEWS = 4 corresponds to a cut point of RI = 16 at similar LR− (and similar sensitivity) and to a cut point of RI = 30 at similar LR+ (and similar positive predictive value). Dataset contained 1,794,910 observations of 32,472 patients. Of the patients, 98.1% survived (n = 31,855; mean age, 65.0 years; SD = 18.6 years) and 1.9% died (n = 617; mean age, 75.7 years; SD = 13.9 years). Abbreviations: CI, confidence interval; LR, likelihood ratio; MEWS, Modified Early Warning Score; RI, Rothman Index; SD, standard deviation.

^*LRs P < 0.0001 for all individual points. LR+ in first pair of columns is significantly different (95% CI: 7.68-7.97; 16.6–17.3), whereas the LR− is virtually the same (95% CI: 0.528-0.546; 0.517-0.535).

^†LR− in second pair of columns is significantly different (95% CI: 0.528-0.546; 0.517-0.535), while the LR+ is virtually the same (95% CI: 7.68-7.97; 7.90-8.07).

^‡LRs were used to select the nearest RI cut point for performance comparisons with MEWS at the times when an alarm was being triggered.