Table 2.
Sensitivity and specificity of WHO “guidelines for care at first-referral level” criteria for antimicrobial treatment in identifying children with invasive bacterial disease (IBD) by rapid diagnostic test (RDT) and blood slide results
| Total cases (No; % died) | No (%) with IBD | Sensitivity—% (95% CI) | Specificity—% (95% CI) | PPV (%) | NPV (%) | NNT* | % fatal cases with IBD treated† | |
|---|---|---|---|---|---|---|---|---|
| RDT and slide negative‡ | 943 (56; 5.9) | 143 (15.2) | 72.7 (69.9 to 75.6) | 47.3 (44.1 to 50.4) | 19.8 | 90.6 | 5.1 | 88.9 |
| RDT positive, slide negative§ | 501 (33; 6.6) | 98 (19.6) | 67.3 (63.2 to 71.5) | 49.9 (45.5 to 54.3) | 24.6 | 86.3 | 4.1 | 83.3 |
| Slide positive <5000/μl | 405 (19; 4.7) | 33 (8.1) | 60.6 (55.9 to 65.4) | 51.9 (47.0 to 56.8) | 10.1 | 93.7 | 10.1 | 80.0 |
| Slide positive 5000-50 000/μl | 917 (33; 3.6) | 31 (3.4) | 67.7 (64.7 to 70.8) | 55.9 (52.7 to 59.1) | 5.1 | 98.0 | 19.6 | 66.7 |
| Slide positive >50 000/μl | 873 (43; 4.9) | 36 (4.1) | 52.8 (49.5 to 56.1) | 51.6 (48.3 to 54.9) | 4.5 | 96.2 | 22.3 | 60.0 |
NPV=negative predictive value; PPV=positive predictive value.
*Number needed to treat presumptively with antimicrobials to correctly treat one child with IBD.
†Proportion of all IBD associated fatalities with “guidelines for care at first-referral level” indication for antimicrobial treatment.
‡56 children were RDT negative and blood slide positive and are included in slide positive data (sensitivity of RDT compared with slide reading was 97.4%).
§Assumed to indicate recent infection with P falciparum.