open defecation and hemoglobin deficiency in young children

Diane Coffeyrice, a research institute for compassionate economics

Office of Population Research, Princeton University

Centre for Development Economics, Delhi School of Economics

prepared for Child Height & Disease Conference,

Aug. 2 & 3, 2013

what is hemoglobin deficiency?

hemoglobin is a protein in red blood cells that carries oxygen

hemoglobin deficiency is a marker of anemia

anemia is defined having hemoglobin concentration below a threshold◦11 gm/dL blood for kids (WHO, 2005)

why does it matter?consequences in adults

◦ reduced work capacity (Basta et al., 1979; Thomas et al., 2004)

◦maternal survival (Rush, 2000)consequences in children

◦ increased susceptibility to infection (Scrimshaw, 2000)

◦ impaired cognitive ability (Grantham McGregor & Ani, 2001)

◦ impaired physical development (Walter et al., 1989)

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WHO (2005) estimated anemia preva-lence among children under five

hypothesis:

open defecation is a cause of hemoglobin

deficiency

outline

background3 analyses

◦1. cross country results◦2. cross sectional results from India &

Nepal◦3. fixed effects results from Nepal

summary, implications for policy & next steps

background

causes of hemoglobin deficiency in young children

• malaria• intestinal parasites• environmental enteropathy• dietary deficiencies

on diet and disease, see Friis et al., 2003

background

links between OD & hemoglobin

• open defecation spreads intestinal parasites – worms live in feces– feces on the ground get onto feet and into mouths– this has been known since at least the 1930s

(Cairncross, 2003)• open defecation exposes kids to fecal

pathogens that could lead to enteropathy

background

links between height & hemoglobin

• this study is consistent with other research on open defecation and height– open defecation thought to cause stunting

through enteropathy and diarrhea• research indicates that hemoglobin deficiency

causes children to be shorter and thinner– larger bodies need more red blood cells to

transport oxygen (see Owen, 1989)

background

3 analyses

1. cross country analysis

data

• hemoglobin: Demographic & Health Surveys from 45 countries– 81 surveys have kids 6-35 months– surveys date from 1995 – 2012– almost 60% of surveys are from SSA

• GDP/capita: Penn World Tables• malaria: WHO incidence estimates (Korenromp, 2005)

cross country analysis

identification

how are open defecation levels across countries and years associated with

hemoglobin levels across countries and years?

cross sectional analysis

open defecation predicts average hemoglobin across countries

specification

• hcry is the average gm/dL of hemoglobin of children 6-35 months in country c, in region r, in year y

• odcry is the fraction of households openly defecating in country c, in region r, in year y

• mcr2004: the country’s estimated incidence of malaria (new cases per year/number of people at risk)

• GDPcry: country and year specific per capita GDP

• y : year fixed effects

cross country analysis

open defecation predicts average hemoglobin across countries

additional specifications (not shown)

• use log of open defecators per square kilometer as an independent variable

• use the 77 country years with hemoglobin measures for kids aged 6 to 59 months

cross country analysis

2. cross sectional analysis from India & Nepal

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data fro

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(uses data

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open defecation is worst in South Asia

from: WHO & Unicef Joint Monitoring Report, 2012

data• India’s National Family Health Survey 3 (2005)

– 36,000 kids 6-59 months with hemoglobin data– 26,000 kids with hemoglobin & food intake data

• Nepal’s Demographic & Health Survey (2011)– 2,100 kids with hemoglobin data– 1,000 kids with hemoglobin & food intake data

cross sectional analysis: India & Nepal

identification

how is open defecation across places within South Asian countries associated

with hemoglobin levels of children in those places?

cross sectional analysis: India & Nepal

summary statistics

specification

• hip is the hemoglobin (gm/dL) of child i in primary sampling unit (PSU) p

• odp is the fraction of households openly defecating in the child’s PSU

• Mip (medicine): does the child take iron supplements?; did she take de-worming medicine in last 6 months?

• Fip (food): breast feeding; number of time fed solid/semi-solid food in last 24 hours; ate meat in last 24 hours; ate dark green leafy vegetables in last 24 hours

cross sectional analysis: India & Nepal

• elecp is the fraction of households in the child’s PSU with electricity

• urbanp is whether or not the child’s PSU is urban

• Eip (mother’s education): linear or dummy variable controls for mother’s education

• SESip (socioeconomic status): child’s household wealth percentile, or asset ownership dummies

• (AipXsexip): 120 sex-specific age-in-month indicators

cross sectional analysis: India & Nepal

open defecation predicts hemoglobin in India

open defecation predicts hemoglobin in Nepal

3. fixed effects analysis from Nepal

data

• Nepal’s Demographic & Health Surveys from 2006 and 2011– 4,680 kids 6-59 months in 2006– 2,100 kids 6-59 months in 2011

• 15 percentage point drop in open defecation from 2006-2011– about 50% of households (2006) to about 35% of

households (2011)

fixed effects analysis: Nepal

identification

how is change over time in open defecation within 25 urban and rural parts of each DHS region (subsequently referred to as

regions) associated with change in hemoglobin levels in those regions?

fixed effects analysis: Nepal

specification

• hiyr: hemoglobin measure of child i, in year y, in region r

• odyr: fraction of HH openly defecating in the child’s region

• elecyr: fraction of HH with electricity in the child’s region

• y: year of survey fixed effect (indicator for 2011)

• δr: region fixed effect

• Eiyr: indicators for mother’s years of education

• SESiyr: economic status dummies

• (Aiyr X sexiyr): 120 sex-specific age-in-month indicators

fixed effects analysis: Nepal

change in open defecation predicts change in hemoglobin in Nepal

summary, implications for policy & next steps

summarydiscussed two mechanisms through

with open defecation could impact hemoglobin◦parasites◦environmental enteropathy

presented results of 3 analyses which support an effect of open defecation on hemoglobin◦cross country results from 81 surveys◦cross sectional results from India & Nepal◦fixed effects results from Nepal

implications for policy (1 of 3)

This study provides econometric evidence

that open defecation may be an important cause of hemoglobin deficiency.

implications for policy (2 of 3)

It suggests that current efforts to improve

hemoglobin by supplementing diets and fortifying foods could be

importantly complemented by

sanitation provision.

implications for policy (3 of 3)

This study adds to a growing body of research

that shows the importance of sanitation for nutrition, particularly

in South Asia.

next steps for this project

compare effect sizes with those associated with other causes of hemoglobin deficiency

control for variation in malaria exposure within South Asia

explore the effect of open defecation on hemoglobin among women

your ideas…?

questions? comments?

hemoglobin level by age in India & Nepal

summary statistics

haemoglobin!