Anaemia: iron tablets increased haemoglobin in 38 year old women.

Clinical bottom line (level 2b)

  1. Thirty-eight year old women with iron deficiency who were given ferrous succinate tablets, were more likely to have a significant increase in haemoglobin concentration than those given placebo.
  2. Women given ferrous succinate were more likely to have side effects (NNH = 3 at unknown) .
Rybo et al: Scandinavian Journal of Haematology (Supplement) 1985; 43: 103-113
Expires June 2003

The study

Double-blinded concealed randomised trial without intention-to-treat
Setting: university hospital, Sweden

113 patients (aged all 38 years, 100% female) 38 year old women with iron deficiency (defined as no or only traces of reticuloendothelial iron in bone marrow)

Excluded if
  • pregnant
  • current iron treatment
  • language difficulties
  • major side effects
  • lack of compliance

Control Group: (n = 56, 44 analysed): placebo
Experimental Group: (n = 57, 45 analysed): ferrous succinate tablets, 37 mg three times a day before meals

79% followed for mean70 days
Outcome notes:
  • side effects : constipation, diarrhoea, epigastric pain or other abdominal complaint or nausea

The evidence

Outcome Time to outcome CEREERRRR
(95% CI)		ARR
(95% CI)		NNH
(95% CI)
side effects unknown 16
(36.4%)		 33
(73.3%)		 -102%
(-210% to -31%)		 -37.0%
(-56.2% to -17.8%)		 3
(2 to 6)

'before' and 'after' results
Outcome Control Group
(SD)		 Experimental Group
(SD)		 Mean Difference
(95% CI)
mean change in haemoglobin concentration (g/l)- iron therapy 129
(12) 		137
(9.0) 		8.0
(3.6 to 12)
mean change in haemoglobin concentration (g/l)- placebo 132
(10) 		133
(10) 		1.0
(-3.2 to 5.3)

Comments

  1. Compliance was ascertained at the end of the trial by a pill count.
  2. Follow-up was so small due to patients being excluded because of major side effects or poor compliance.
  3. Such a small follow-up makes the results less reliable.
  4. Lower dose than usual given (typically 200 mg twice tds po) and many patients had haemoglobin levels not usually considered to be anaemic. This paper evidences that low doses of ferrous succinate tablets work better than placebo in premenstrual adult nonpregnant females.
  5. However, this trial also evidences that even low doses may have frequent non serious abdominal side effects.

Citation

  1. Rybo E, Bengtsson C, Hallberg L, et al: Effect of iron supplementation to women with iron deficiency. Scandinavian Journal of Haematology (Supplement) 1985; 43: 103-113
Contributor: Clare Wotton and Martin Dawes, June 2000
Reviewer: Santiago Alvarez Montero

Clinical Question.
Patient women with iron deficiency
Intervention or Exposure iron supplementation
Comparison placebo
Outcome response to treatment