| Methods |
Design: four group parallel trial
Purpose: examine the effect of iron supplement on acute blood loss anaemia after surgery |
| Participants |
Patients: postoperative out‐patients
Baseline comparability: yes for age and sex. |
| Interventions |
Placebo: NS
Untreated: no placebo or iron
Experimental: iron supplement at two doses
(Co‐intervention: no) |
| Outcomes |
Hb concentration (mg Hgl/dl) (59 days after surgery)
Haematocrit
Serum‐iron
Serum‐ferritin |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Adequate sequence generation? |
Unclear risk |
'computer‐generated table of random numbers' |
| Allocation concealment? |
Unclear risk |
NS |
| Blinding?
Treatment provider |
Low risk |
'Consenting patients were randomized into four groups in a double‐blind fashion...' |
| Blinding?
Outcome assessor |
Unclear risk |
NS |
| Incomplete outcome data addressed?
All outcomes |
Low risk |
Drop‐out < 15% |
| Free of selective reporting? |
Unclear risk |
No protocol available |
| Free of other bias? |
Low risk |
|
| No signs of variance inequality or skewness? |
Low risk |
No variance inequality (F‐test not statistically significant) and no skewness (1.64 standard deviations does not exceed the mean) |
| Trial size > 49? |
Low risk |
N = 59 |
| Clearly concealed allocation + trial size > 49 + drop‐out max 15% |
High risk |
Allocation not clearly concealed |
