Table 2.
Misclassification rates for tachypnoea when using mean RR
| Children with RR ≥ percentile and WHO upper threshold*(true positives; a) | Children with RR ≥ WHO upper threshold*but < percentile (false positives; b) | Children with RR ≥ percentile but < WHO upper threshold*(false negatives; c) | Children with RR < percentile and WHO upper threshold*(true negatives; d) | False positives for tachypnoea, % (95% bootstrap CI) | False negative for tachypnoea, % (95% bootstrap CI) | Total misclassification, % (95% bootstrap CI) | |
|---|---|---|---|---|---|---|---|
| 95th percentile | |||||||
| India | 1 | 0 | 21 | 382 | 0·0 (0–0) | 95·5% (87·4–100) | 5·2% (3·2–6·9) |
| Guatemala | 20 | 27 | 0 | 342 | 7·3% (4·1–10·4) | 0·0 (0–9·7) | 6·9% (4·0–9·9) |
| Rwanda | 19 | 54 | 0 | 268 | 16·8% (12·9–21·1) | 0·0 (0–1·7) | 15·8% (12·1–20·2) |
| Peru | 14 | 122 | 0 | 300 | 28·9% (23·7–33·0) | 0·0 (0–1·9) | 28·0% (22·6–31·9) |
| 90th percentile | |||||||
| India | 1 | 0 | 42 | 361 | 0·0 (0–0) | 97·7% (92·9–100) | 10·4% (7·3–12·4) |
| Guatemala | 33 | 14 | 7 | 335 | 4·0% (1·8–6·5) | 17·5% (0·8–36·8) | 5·4% (3·6–7·8) |
| Rwanda | 32 | 41 | 0 | 268 | 13·3% (8·8–17·7) | 0·0 (0–8·4) | 12·0% (8·1–16·3) |
| Peru | 31 | 105 | 0 | 300 | 25·9% (20·4–30·1) | 0·0 (0–7·5) | 24·1% (18·6–28·0) |
RR=respiratory rate. Data are n, unless otherwise specified.
*
WHO upper threshold ≥60 breaths per min for children 0–1 months, ≥50 breaths per min for children 2–11 months, ≥40 breaths per min for children 12–23 months. We define the false positive rate for tachypnoea as b/(b + d), the false negative rate for tachypnoea as c/(a + c), and the total misclassification rate for tachypnoea as (b + c)/(a + b + c + d).