Table 4.
Incidence of admission to Kilifi County Hospital among children with sickle cell disease, stratified by baseline factors
| Admissions | Person-years of observation | Incidence | IRR (95% CI) | p value | Adjusted IRR (95% CI)* | p value | |
|---|---|---|---|---|---|---|---|
| Sickle cell disease clinic enrolment | |||||||
| No | 23 | 208 | 110 | 1 (ref) | .. | 1 (ref) | .. |
| Yes | 86 | 311 | 276 | 2·16 (1·19–3·91) | 0·011 | 2·02 (1·10–3·70) | 0·022 |
| Haemoglobin F | |||||||
| Below the median | 74 | 252 | 293 | 1 (ref) | .. | 1 (ref) | .. |
| Above the median | 35 | 267 | 131 | 0·51 (0·29–0·89) | 0·018 | 0·43 (0·24–0·78) | 0·0048 |
| α+thalassaemia | |||||||
| Normal | 59 | 218 | 269 | 1 (ref) | .. | 1 (ref) | .. |
| Heterozygous | 44 | 212 | 207 | 0·96 (0·56–1·65) | 0·91 | 1·09 (0·62–1·89) | 0·75 |
| Homozygous | 6 | 83 | 72 | 0·26 (0·07–0·87) | 0·030 | 0·07 (0·01–0·83) | 0·035 |
| β-thalassaemia | |||||||
| With β-thalassaemia | 100 | 476 | 209 | 1 (ref) | .. | 1 (ref) | .. |
| Without β-thalassaemia | 9 | 43 | 206 | 0·90 (0·33–2·42) | 0·83 | 1·08 (0·38–3·06) | 0·87 |
IRR=incidence rate ratio.
*
IRRs adjusted for α-thalassaemia genotype and ethnic group.