title: Cluster-randomised trial of the impact of school-based deworming and iron supplementation on the cognitive abilities of schoolchildren in Sri Lanka's plantation sector.
abstract: OBJECTIVE
  To assess the impact of deworming and iron supplementation on the cognitive abilities and educational achievement of school-age children in Sri Lanka.
  
  
  METHODS
  Prospective, placebo-controlled randomised study. The treatment group received deworming and weekly iron supplementation for 6 months; the control group received placebo for both the anthelmintic and iron. A mixed effects regression model was used to answer the main research question. To increase the precision of this study's estimates, various background variables were controlled for that were not related to treatment but could have some impact on the outcome.
  
  
  RESULTS
  The prevalence of soil-transmitted helminth (STH) infection was reduced in the treatment group (n = 615), with significant differences between treatment and control groups (n = 575) in the levels of Ascaris and Trichuris. No impact was found on haemoglobin (Hb) levels, nor any significant impact on concentration levels or on educational test scores.
  
  
  CONCLUSIONS
  Decline in STH prevalence alone, in the absence of improved Hb status, produced no evidence of impact on concentration levels or educational test scores.
authors.affiliation: South Asia Region, Education Department, World Bank Group, Washington, DC, USA. rebenezer@worldbank.org
authors.forename: Roshini
authors.initials: R
authors.lastname: Ebenezer
authors.forename: Kithsiri
authors.initials: K
authors.lastname: Gunawardena
authors.forename: Balachandran
authors.initials: B
authors.lastname: Kumarendran
authors.forename: Arunasalam
authors.initials: A
authors.lastname: Pathmeswaran
authors.forename: Matthew C H
authors.initials: MC
authors.lastname: Jukes
authors.forename: Lesley J
authors.initials: LJ
authors.lastname: Drake
authors.forename: Nilanthi
authors.initials: N
authors.lastname: de Silva
mesh_terms: D000723:Ancylostomatoidea / Q000302:isolation & purification; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000188:drug therapy* / Q000453:epidemiology; D000818:Animals; D000969:Antinematodal Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001200:Ascaris / Q000302:isolation & purification; D002648:Child; D016000:Cluster Analysis; D003071:Cognition / Q000502:physiology; D019587:Dietary Supplements; D004521:Educational Measurement; D004522:Educational Status; D005243:Feces / Q000469:parasitology; D005260:Female; D005296:Ferrous Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008463:Mebendazole / Q000008:administration & dosage / Q000627:therapeutic use*; D009349:Nematode Infections / Q000188:drug therapy* / Q000453:epidemiology; D010270:Parasite Egg Count; D010919:Placebos; D011446:Prospective Studies; D012044:Regression Analysis; D012572:School Health Services; D013188:Sri Lanka / Q000453:epidemiology; D014258:Trichuris / Q000302:isolation & purification
chemical_list: D000969:Antinematodal Agents; D005296:Ferrous Compounds; D006454:Hemoglobins; D010919:Placebos; C020748:ferrous sulfate; D008463:Mebendazole
keywords: Sri Lanka; cognition; deworming; educational achievement; iron supplementation; school health and nutrition