title: Accuracy of erythrogram and serum ferritin for the maternal anemia diagnosis (AMA): a phase 3 diagnostic study on prediction of the therapeutic responsiveness to oral iron in pregnancy.
abstract: BACKGROUND
  Pregnancy anemia remains as a public health problem, since the official reports in the 70's. To guide the treatment of iron-deficiency anemia in pregnancy, the haemoglobin concentration is the most used test in spite of its low accuracy, and serum ferritin is the most reliable test, although its cutoff point remains an issue.
  
  
  METHODS
  The aim of this protocol is to verify the accuracy of erythrocyte indices and serum ferritin (studied tests) for the diagnosis of functional iron-deficiency in pregnancy using the iron-therapy responsiveness as the gold-standard. This is an ongoing phase III accuracy study initiated in August 2011 and to be concluded in April 2013. The subjects are anemic pregnant women (haemoglobin concentration < 11.0 g/dL) attended at a low-risk prenatal care center in the Northeast of Brazil. The sample size (n 278) was calculated to estimate sensitivity of 90% and 80% of specificity with relative error of 10% and power of 95%. This study has a prospective design with a before-after intervention of 80 mg of daily oral iron during 90 days and will be analyzed as a delayed-type cross-sectional study. Women at the second trimester of pregnancy are being evaluated with clinical and laboratorial examinations at the enrollment and monthly. The 'responsiveness to therapeutic test with oral iron' (gold-standard) was defined to an increase of at least 0.55 Z-score in haemoglobin after 4 weeks of treatment and a total dose of 1200 mg of iron. At the study conclusion, sensitivities, specificities, predictive values, likelihood ratios and areas under the ROC (Receiver Operating Characteristic) curves of serum ferritin and erythrocyte indices (red blood cell count, haematocrit, haemoglobin concentration, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, red blood cell distribution width, reticulocyte count) will be tested. The compliance and adverse effects are considered confounding variables, since they are the main obstacles for the iron-therapy responsiveness.
  
  
  CONCLUSIONS
  This study protocol shows a new approach on iron-deficiency anemia in pregnancy from a functional point of view that could bring some insights about the diagnostic misclassifications arising from the dynamic physiologic changes during the gestational cycle.
  
  
  BACKGROUND
  WHO International Clinical Trials Registry Platform U1111-1123-2605.
authors: Nutrition Research Group at Instituto de Medicina Integral Prof Fernando Figueira - IMIP, Rua dos Coelhos, 300, Boa Vista, Recife, PE CEP: 50,070-550, Brazil. cristiane.bresani@inss.gov.br
authors: Cristiane Campello
authors: CC
authors: Bresani
authors: Maria Cynthia
authors: MC
authors: Braga
authors: Daniel Falcão
authors: DF
authors: Felisberto
authors: Carlos Eduardo Lopes
authors: CE
authors: Tavares-de-Melo
authors: Debora Bresani
authors: DB
authors: Salvi
authors: Malaquias
authors: M
authors: Batista-Filho
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000175:diagnosis* / Q000188:drug therapy; D001938:Brazil; D003430:Cross-Sectional Studies; D004909:Erythrocyte Indices; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D007501:Iron / Q000008:administration & dosage* / Q000009:adverse effects; D055118:Medication Adherence; D011237:Predictive Value of Tests; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis* / Q000188:drug therapy; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D062606:Tertiary Care Centers
chemical_list: D005293:Ferritins; D007501:Iron