Summary of findings 1. Hydroxyurea versus placebo or standard care for non‐transfusion dependent beta thalassaemia.

Hydroxyurea compared with placebo for people with non‐transfusion dependent beta thalassaemia
Patient or population: people with non‐transfusion dependent beta thalassaemia Intervention: hydroxyurea Comparison: placebo or standard care
Outcomes	Illustrative comparative risks (95% CI)		Relative effect (95% CI)	No of Participants (studies)	Quality of the evidence (GRADE)	Comments
	Assumed risk	Corresponding risk
	Placebo	Hydroxyurea
Frequency of transfusion	No trials found.
Major adverse effects	No trials found.
Quality of life	No trials found.
Mean Hb F (g/dL)	No trials found.
CI: confidence interval; Hb F: foetal haemoglobin.
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.