Zhu 1998.
| Methods |
Design: randomised controlled trial Randomisation: individual Trial: daily oral iron versus placebo Date of study: not stated |
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| Participants |
Setting: Ithaca (Cornell University, USA) Malaria endemicity: not stated Included: women aged 19 years to 36 years (mean age 36 years) with haemoglobin > 120 g/L and ferritin < 16 ng/mL Excluded: current pregnancy or pregnancy within the past year, infectious illness in the past month, fever in the past week, haemolytic anaemia, asthma, musculoskeletal problems, smoking, excess alcohol consumption (more than seven glasses of an alcoholic beverage per week), recent history of eating disorders, and use of prescription medications that potentially interfere with dietary iron absorption Dropouts: 2 of 39 (1 in each arm) Sample Size: total: 37; intervention: 20, control: 17 |
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| Interventions |
Intervention: 135 mg elemental iron daily (45 mg thrice daily) as ferrous sulphate Control: placebo Duration: 8 weeks |
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| Outcomes | Haemoglobin, iron status, exercise performance, fat mass, weight, lactate | |
| Notes |
Compliance: on average, the placebo group consumed 144 ± 23 capsules (87.3 ± 9.5% of the total prescription) and the iron‐supplemented group consumed 145 ± 29 capsules (87.5 ± 16.5% of the total prescription); no significant difference between these arms Conflicts of interest: not stated Funded by: United States Department of Agriculture Grant (9500850) and by a Graduate Research Grant from the Division of Nutritional Sciences, Cornell University |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | Not reported |
| Allocation concealment (selection bias) | Unclear risk | Not reported |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Placebo administered |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Not reported. Unlikely to affect biochemical/laboratory indices but could affect assessor's measurement of exercise performance |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | 39 enrolled. 2 lost to follow‐up, 1 in each arm |
| Selective reporting (reporting bias) | Low risk | Not evident |
| Other bias | Low risk | Not evident |
BMI ‐ body mass index CI(s) ‐ confidence interval(s) GP ‐ general practitioner Fe ‐ iron FEP ‐ free erythrocyte protoporphyrin HR ‐ heart rate ICC ‐ intraclass correlation coefficient PR blood loss ‐ bleeding in any part of the gastrointestinal tract SD ‐ standard deviation SE ‐ standard error TFT ‐ thyroid function test UNICEF ‐ United Nations International Children's Emergency Fund VO₂ max ‐ maximal oxygen consumption