Do side-effects reduce compliance to iron supplementation? A study of daily- and weekly-dose regimens in pregnancy.
Side-effects of iron supplementation lead to poor compliance. A weekly-dose schedule of iron supplementation rather than a daily-dose regimen has been suggested to produce fewer side-effects, thereby achieving a higher compliance. This study compared side-effects of iron supplementation and their impact on compliance among pregnant women in Bangladesh. These women were assigned to receive either weekly doses of 2 x 60 mg iron (one tablet each Friday morning and evening) or a daily dose of 1 x 60 mg iron. Fifty antenatal care centres were randomly assigned to prescribe either a weekly- or a daily-supplementation regimen (86 women in each group). Side-effects were assessed by recall after one month of supplementation and used for predicting compliance in the second and third months of supplementation. Compliance was monitored using a pill bottle equipped with an electronic counting device that recorded date and time whenever the pill bottle was opened. Of five gastrointestinal side-effects (heartburn, nausea, vomiting, diarrhoea, or constipation) assessed, vomiting occurred more frequently in the weekly group (21%) than in the daily group (11%, p<0.05). Compliance (ratio between observed and recommended tablet intake) was significantly higher in the weekly-supplementation regimen (93%) than in the daily-supplementation regimen (61%, p<0.05). Overall, gastrointestinal side-effects were not significantly associated with compliance. However, the presence of nausea and/or vomiting reduced compliance in both the regimens-but only among women from the lower socioeconomic group. In conclusion, weekly supplementation of iron in pregnancy had a higher compliance compared to daily supplementation of iron despite a higher frequency of side-effects. The findings support the view that gastrointestinal side-effects generally have a limited influence on compliance, at least in the dose ranges studied. Efforts to further reduce side-effects of iron supplementation may not be a successful strategy for improving compliance and effectiveness of antenatal iron supplementation.
Research and Evaluation Division, BRAC, Mohakhali, Dhaka, Bangladesh. ziahyder@bdonline.com
S M Ziauddin
SM
Hyder
Lars Ake
LA
Persson
A M R
AM
Chowdhury
Eva-Charlotte
EC
Ekström
D018798:Anemia, Iron-Deficiency / Q000517:prevention & control; D001459:Bangladesh; D019587:Dietary Supplements; D004064:Digestive System / Q000187:drug effects; D004334:Drug Administration Schedule; D005260:Female; D005767:Gastrointestinal Diseases / Q000139:chemically induced; D006801:Humans; D007501:Iron / Q000008:administration & dosage / Q000009:adverse effects*; D010349:Patient Compliance; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000517:prevention & control*; D012959:Socioeconomic Factors
D007501:Iron