evaluating hiv prevention and treatment programs
DESCRIPTION
Evaluating HIV Prevention and Treatment Programs. Damien de Walque Markus Goldstein. (Impact) Evaluating Health Programs is different. Norm in medicine to use randomized control trials to figure out what works What we know less about (for example): - PowerPoint PPT PresentationTRANSCRIPT
Evaluating HIV Prevention and Treatment Programs
Damien de WalqueDamien de Walque
Markus GoldsteinMarkus Goldstein
2
(Impact) Evaluating Health Programs is different
• Norm in medicine to use randomized control trials to figure out what works
• What we know less about (for example):
– Socioeconomic effects of health interventions
– How to get people to utilize treatment (e.g. vaccines)
– What is the most cost effective mode of treatment
3
This is an issue for HIV/AIDS
• Examples:
– ART works biologically, but what impact does it have on patients socio-economic status?
– Circumcision is effective in reducing HIV risk, how do we get people to volunteer?
– We know different prevention interventions have some effect – which is the most cost effective?
4
This presentation
• We will not focus on the medical findings
• We know something about non-medical outcomes through evaluation, but actually not that much rigorous (in a comparison group sense) evidence
• But, a lot in progress, and we will talk about some of that
5
Example 1• Duflo, Dupas, Kremer & Sinei: Education and HIV
AIDS Prevention
• The interventions:1. training teachers in the Kenyan government’s
HIV/AIDS-education curriculum2. organized debate and essay contest on the role of
condoms in protecting teens against HIV/AIDS3. reduced cost of education through the supply of school
uniforms4. information campaign for Kenyan teenagers to spread
the awareness of high HIV prevalence among adult men (uses earlier evaluation work)
6
Evaluation design– Schools randomly assigned to treatment groups
and control– Baseline and endline data collection to use a
difference in difference approach– Measured the effect of the program on:
• Teacher coverage of HIV/AIDS• Student HIV knowledge• Student attitudes• Self reported behavior• Child bearing (girls) and drop out rates
7
Main findings
– Teacher training led to no significant reduction in teen pregnancy, but increased likelihood that pregnancies occur within marriage
– Debate over condoms led to (some) increased report of condom use
– Reductions in the cost of schooling led to reduction in drop out rates and reduction in teen pregnancies
8
Prevention of HIV/AIDS
$575
$300
$91
$0
$100
$200
$300
$400
$500
$600
$700
Co
st
per
pre
gn
an
cy a
vert
ed
Teacher training Uniforms Info. Campaigns
Source: Duflo, Dupas, Kremer, and Sinei (2006)
9
Example 2• Thirumurthy, Graff Zivin, and Goldstein: The Economics of
AIDS Treatment: Labor Supply in Western Kenya
• The intervention
– Provide ART to patients, rule is for a CD4<200, but initial rationing
– Treatment for opportunistic infections
– Nutrition supplementation, but not much until later
• Data – two rounds of hh survey – random sample & patients
10
Evaluation DesignWe know what happens to counterfactual
groupMedical evidence: continued decline in health
and death
Allows estimation of upper bound of treatment impact
Zero labor supply in round 2
010
2030
Mea
n ho
urs
wor
ked
in p
ast w
eek
-50 0 50 100 150 200 250 300 350 400Days on ARVs
treated counterfactual
11
BMI Before and After ARV Therapy
Source: AMPATH Medical Records System – data as of March 2005.
.6.7
.8.9
Fra
ctio
n pa
rtic
ipat
ing
in la
bor
forc
e
-8 0 8 16 24 32 40 48 56Weeks on ARVs
LFP before and after ARV Therapy
Source (right): Household survey data.
19
20
21
22
Me
dia
n B
MI
-40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90Weeks Before/After ARV Initiation
12
Main Findings
• Large and rapid labor supply response in patients
• Spillover benefits to other members of the household – young boys & women reduce their labor supply
• Patient earnings (relative to zero counterfactual) are close to the cost of treatment
Some work in progress
14
Question 1: Socio-economic impact of reducing premature adult mortality: the case of
ART
• In addition to labor supply:
• Schooling and welfare of children
• How household coping mechanisms change with ART
• Effects of ART on farming productivity
• Using evaluation results for macro models of the economic effects of AIDS & treatment
15
Question 2: Possible effects of ART on HIV transmission and prevention
Direction of effect
Beneficial(Slow transmission)
Adverse(Speed transmission)
Type of effect
Biological
Reduce infectiousness Select for resistance.
Longer duration of infectivity
Behavioral
Encourage prevention,especially testing
Off-setting behavior, “disinhibition”
16
Other questions (more on the supply- facility side)
• 3) Adherence to treatment
• 4) How to avoid the development and spread of resistance?
• 5) How are ART beneficiaries identified? How to encourage timely uptake?
• 6) How to assure the quality of HIV/AIDS service delivery?
• 7) How to encourage capacity building to reinforce the sustainability of ART delivery?
17
Methodology and data collection (Longitudinally)
• Biomedical follow-up including data on treatment regimen and treatment success (CD4 counts)
• Household surveys (HIV patients and general population) including health, schooling, labor force.
• 7 countries: Burkina Faso, Ghana, Kenya, India, Mozambique, Rwanda and, South Africa
• Surveys ongoing and scheduled. Data and preliminary analysis will be available by the end of 2008.
18
DeterminantsPatient
and ProviderBehavior
OutcomesImpact on
the entire country
Treatment Outcome, Resistance
Development
Socio-Economic benefits
for households
Prevention
PatientAdherence Information
socio-economicvariables
Community variables
Stigmatization
Training
Selection / Recruiting
Impact On health systemQuality of
service deliveryEquipment
Staffing and Incentives
Associations
EmployersSocio-
Economic benefits for firms
Framework for Learning Agenda
19
Methodological challenges: endogeneity
• Given issues with randomization, in some countries, we will evaluate some experiments on the conditions of ARV delivery.
• Rwanda: performance-based contracting for HIV/AIDS services in health facilities
• South Africa: food and counseling intervention as adherence support.
• Kenya: text messaging intervention as reminders for adherence
20
Some other common issues for HIV evaluations
• Measurement. Dupas & co. raise the issue of what should be the impact variable, particularly in prevention
– Issue of self reported behavior (Gersovitz)
– Think about using biomarkers – HIV or STI?
21
Comdom use at the last intercourse with the spouse: discordant reports
Source: DHS 2003 and 2004
N =
Burkina Faso
1630
Cameroon
1764
Ghana
1830
Kenya
1361
Tanzania
2497
Man no,
Woman no
88.9% 90.8% 91.9% 97.0% 90.9%
Man yes,
Woman yes
2.0% 2.2% 1.9% 1.0% 1.6%
Man yes, woman no
6.9% 4.2% 5.0% 1.8% 4.3%
Man no,
Woman yes
2.2% 2.8% 1.2% 0.3% 3.2%
22
Issues in HIV evaluation, cont.• Control Group: Thirumurthy et. al. point to the problem of a
medical intervention known to be effective and the problem of generating a counterfactual
– Sequel paper looks at children, here the authors use a range of control group techniques
• The shape & determinants of the epidemic vary across time and across countries, so results in one country may not apply to another…need to do multiple evaluations of the same intervention