A rapid, simple questionnaire to assess gastrointestinal symptoms after oral ferrous sulphate supplementation.

Dora IA Pereira,Miranda CE Lomer,Susana S Couto Irving,Jonathan J Powell

doi:10.1186/1471-230x-14-103

Dora IA Pereira, Miranda CE Lomer + Show 2 more

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https://doi.org/10.1186/1471-230x-14-103

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Abstract

BackgroundOral iron supplementation is often associated with rapid onset of gastrointestinal side-effects. The aim of this study was to develop and trial a short, simple questionnaire to capture these early side-effects and to determine which symptoms are more discriminating.MethodsThe study was a double-blind placebo-controlled randomized parallel trial with one week treatment followed by one week wash-out. Subjects were randomized into two treatment groups (n = 10/group) to receive either ferrous sulphate (200 mg capsules containing 65 mg of iron) or placebo, both to be taken at mealtimes twice daily during the treatment period. Subjects completed the questionnaires daily for 14 days. The questionnaire included gastrointestinal symptoms commonly reported to be associated with the oral intake of ferrous iron salts (i.e. nausea, vomiting, heartburn, abdominal pain, diarrhoea, and constipation).ResultsSeventy five per cent of participants reporting the presence of one or more symptoms in the first week of the study were in the ferrous sulphate group. In the second week of the study (i.e. wash-out), 67% of the participants reporting one or more symptom(s) were in the ferrous sulphate group. In the first week of the study (treatment) the number of symptoms reported by participants in the ferrous sulphate group (mean ± SEM = 6.7 ± 1.7) was significantly higher than that for participants in the placebo group (1.2 ± 0.5) (p = 0.01). In the second week of the study (wash-out) the number of symptoms reported by participants in the ferrous sulphate group (4.6 ± 2.0) appeared higher than for participants in the placebo group (1.0 ± 0.7) although this did not reach significance (p = 0.12). Events for which the gastrointestinal symptom questionnaire was most discriminatory between ferrous sulphate and placebo groups were: heartburn, abdominal pain and the presence of black stools (all p ≤ 0.03).ConclusionsA tool for the detection of commonly-occurring side effects should not require large study numbers to be effective. With just 10 subjects per group (iron or placebo), this simple questionnaire measures gastrointestinal side-effects associated with oral iron (ferrous sulphate) supplementation, and would be appropriate for use in intervention studies or clinical trials.Trial registrationClinicalTrials.gov Identifier: NCT02146053 (21/05/2014).

Highlights

Oral iron supplementation is often associated with rapid onset of gastrointestinal side-effects
The current study presents a simple one-page gastrointestinal symptom questionnaire (a) to capture the early side-effects normally associated with oral iron supplementation and (b) to determine which symptoms are more discriminant
A short and simple-to-answer gastrointestinal symptom questionnaire was developed as a tool to measure adverseeffects for use in intervention studies with oral iron and especially when ferrous sulphate comprises one study arm

Summary

Introduction

Oral iron supplementation is often associated with rapid onset of gastrointestinal side-effects. Despite many attempts to eradicate or even reduce iron deficiency anaemia (IDA), it remains the most prevalent nutritional deficiency disorder in the world affecting around 1.1 billion people of which nearly 400 million are children. Iron deficiency anaemia accounts for 2.4% of the global disease burden and it occupies the World Health Organization (WHO) top ten hit list of targeted global health problems [1,2,3]. Gastrointestinal side-effects start to present early in the treatment course [7,16,17] albeit onset of symptoms and severity must be related to the iron dosage and the posology followed (i.e. weekly or daily) [18,19,20,21,22,23]. Gastrointestinal symptoms impact on the general wellbeing of individuals [30,31,32,33,34,35,36,37] and are known to affect compliance with oral iron therapy and, treatment efficacy [7,19,38,39,40]

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