Download Open defecation and hemoglobin deficiency in young children

sanitation externalities,
disease and
children’s anemia
Diane Coffey
Office of Population Research, Princeton University
prepared for PAA session on Public Health & Demography,
May 2, 2014
what is anemia?

hemoglobin: a protein in red blood cells
that carries oxygen

anemia: lack of hemoglobin
◦ hemoglobin concentration below 11 gm/dL
blood (WHO, 2005) in children
why does anemia matter?

Scrimshaw, 2000: increased susceptibility
to infection

Grantham McGregor & Ani, 2001: impaired
cognitive ability

Walter et al. 1989: impaired physical
development

Stevens et al., 2011: globally, 43% of
children anemic; 58% in South Asia
causes of anemia

diet: iron, vitamin B12, folate

diseases
◦ intestinal parasites
◦ environmental enteropathy
◦ malaria

blood loss
hypothesis
outline

background
◦ why is this link plausible?
◦ sanitation externalities

empirical results
◦ cross country gradient
◦ cross sectional results from India & Nepal
◦ fixed effects results from Nepal

policy implications
◦ does poor sanitation make other interventions
less effective?
background
why is this link plausible?
diseases caused by open defecation
• intestinal parasites
– feces on the ground spread parasites that
enter kids’ bodies by the feet and mouth
(Rosenberg & Bowman, 1982)
• environmental enteropathy
– bacteria in feces reduces absorptive
capacity of intestines (Walker, 2003;
Humphrey, 2009)
background
why is this link plausible?
open defecation and height
• growing literature in economics and
epidemiology finds effects on height
– Bangladesh: Lin et al., 2013
– Indonesia: Cameron et al., 2013
– India: Hammer & Spears, 2012
– international: Spears, 2012
• height and hemoglobin could be influenced
by similar intestinal diseases
background
sanitation externalities
Observations are children in India’s 2005 DHS.
empirical results
cross country gradient
data
• hemoglobin & open defecation: DHS
– 81 surveys from 45 countries
– 1995 – 2012
– 60% of surveys are from SSA
• GDP per capita & population density: Penn
World Tables & World Bank
• malaria: WHO incidence estimates (Korenromp,
2005)
cross country motivation
R2 = 0.26
density of open
defecation and
hemoglobin in
81 DHS
R2 = 0.23
open defecation density
and hemoglobin in 81
DHS – net of malaria
2
R
= 0.43
regression gradients:
density of open defecation & hemoglobin
no controls
0
-0.05
-0.1
-0.15
-0.2
-0.25
-0.3
-0.35
+ malaria
+ per capita GDP
+ year fixed
effects
fixed effects results from Nepal
data
• Nepal’s Demographic & Health Surveys from
2006 and 2011
– 2006: 4,680 kids 6-59 months
– 2011: 2,100 kids 6-59 months
• 15 percentage point drop in open defecation
– 2006: 50% of households
– 2011: 35% of households
fixed effects results
identification
how is change over time in open
defecation within 25 regions
associated with change in
hemoglobin levels in those regions?
fixed effects results
change over time in open defecation within
Nepali regions predicts change in hemoglobin
policy implications
in India, associations between parasite medicine
and hemoglobin and iron pills and hemoglobin are
weaker where there is more open defecation
difference in hemoglobin levels
between kids who took parasite
medicine and those who did not
difference in hemoglobin levels
between kids who took iron pills
and those who did not
0.5
0.5
0.4
0.4
0.3
0.3
0.2
0.2
0.1
0.1
0
0
10% community 90% community
open defecation open defecation
10% community 90% community
open defecation open defecation
summary
This study adds to a growing
body of research that shows
the importance of sanitation
for nutrition, particularly in
South Asia.
summary
This study provides
econometric evidence that
open defecation may spread
diseases that cause anemia.
summary
It suggests that efforts to
improve anemia by
supplementing diets and
treating parasites could be
importantly complemented by
greater attention to
sanitation.
questions?
comments?
the association between parasite
medicine and hemoglobin is greater
where there is less open defecation
difference =
0.4 gm/dL
difference =
0.2 gm/dL
10%
90%