Table 2.
The performance of screening methods in the detection of duct dependent circulation in newborn infants in West Götaland (1 July 2004 to 31 March 2007)
| Performance | Physical examination alone (n=38 374) | Pulse oximetry (n=38 429) | Physical examination plus pulse oximetry (n=38 429) |
|---|---|---|---|
| Sensitivity (95% CI) (%) | 62.50 (35.43 to 84.80)* | 62.07 (42.3 to 79.31) | 82.76 (64.23 to 94.15) |
| Specificity (95% CI) (%) | 98.07 (97.93 to 98.21) | 99.82 (99.77 to 99.86) | 97.88 (97.73 to 98.03) |
| Positive predictive value (95% CI) (%) | 1.35 (0.65 to 2.47) | 20.69 (12.75 to 30.71) | 2.92 (1.88 to 4.31) |
| Negative predictive value (95% CI) (%) | 99.98 (99.96 to 99.99) | 99.97 (99.95 to 99.99) | 99.99 (99.97 to 100.00) |
| Likelihood ratio | 32.37 | 344.8 | 39.08 |
| False-positive rate (%) | 1.90 | 0.17† | 2.09 |
| No of true positives | 10* | 18‡ | 24‡ |
| No of false negatives | 6* | 11§ | 5§ |
| No of false positives | 729 | 69 | 798 |
| No of true negatives | 37 022 | 38 259 | 36 881 |
| Relative risk (95% CI) (%) | 83.6 (30.5 to 229.5) | 719.8 (350.3 to 1479) | 215.4 (82.4 to 563.0) |
*Blind physical examination alone cannot be compared directly with the other two methods as the number of babies with duct dependent circulation was 16 in this group.
†False positive rate calculated on total numbers of patients completing pulse oximetry (n=39 821).
‡Patient who was diagnosed after repeated failures of obtaining a pulse oximetry signal in the feet is counted as true positive.
§Patient who fulfilled screening criteria but was discharged due to protocol violation is counted as false negative.