Summary of findings 2. Different doses or dose regimens of hydroxyurea compared.
| Different doses or dose regimens of hydroxyurea compared | ||||||
| Patient or population: people with non‐transfusion dependent beta thalassaemia Settings: specialised outpatient clinic Intervention: 20 mg/kg/day hydroxyurea versus 10 mg/kg/day | ||||||
| Outcomes | Illustrative comparative risks* (95% CI) | Relative effect (95% CI) | No of Participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| 10 mg/kg/day | 20 mg/kg/day | |||||
| Frequency of transfusion | Outcome not reported. | |||||
| Major adverse effects ‐ Neutropenia | Study population | RR 9.93 (1.34 to 73.67) | 61 (1 trial) | ⊕⊝⊝⊝ very low1,2,3 | Not downgraded for lack of blinding because outcome considered to be objective. | |
| 31 per 1000 | 310 per 1000 (42 to 1000) | |||||
| Major adverse effects ‐ Thrombocytopenia | Study population | RR 3.68 (1.12 to 12.07) | 61 (1 trial) | ⊕⊝⊝⊝ very low1,2,3 | Not downgraded for lack of blinding because outcome considered to be objective. | |
| 94 per 1000 | 345 per 1000 (105 to 1000) | |||||
| Quality of life | Outcome not reported | |||||
| Mean Hb F at 24 weeks (g/dL) | The mean Hb F at 24 weeks (g/dL) in the intervention group was 1.5 lower (1.83 to 1.17 lower) | 61 (1 trial) | ⊕⊕⊝⊝ low1,2 | Not downgraded for lack of blinding because outcome considered to be objective. | ||
| *The risk in the intervention group (and its 95% CI) is based on the assumed risk in comparison group and the relative effect of the intervention (and its 95% CI). CI: confidence interval; Hb F: foetal haemoglobin; RR: risk ratio. | ||||||
| GRADE Working Group grades of evidence High quality: further research is very unlikely to change our confidence in the estimate of effect. Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate. Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. Very low quality: we are very uncertain about the estimate. | ||||||
1 Downgraded one level for unclear allocation concealment 2 Downgraded one level because conclusions based on one small trial 3 Downgraded one level for extremely wide CI