Population-based

HIV Impact Assessments (PHIA):

An Introduction Focusing on Malawi and Zimbabwe 

  Elizabeth Radin, PhD

Technical Specialist – Population-based SurveysProject Director, Malawi & Zimbabwe PHIAs

November 6, 2014

Presentation Objectives

1. Explain what ICAP’s PHIAs are2. Explain why ICAP is doing PHIAs from both a

SCIENTIFIC and POLICY perspective 3. Present how we are approaching the first two

PHIAs in Malawi and Zimbabwe4. Share information on the future of PHIAs at

ICAP

What are ICAP’s PHIAs

Population-based HIV Impact AssessmentA survey that is:• Nationally-led (MOH, NSO) • In collaboration with CDC• Cross-sectional• Household-based• Nationally and Sub-nationally Representative• Focused on impact-level indicators of the HIV

epidemic through biomarkers and self report

What we mean by ‘Impact Assessment’

IMPACTS

OUTCOMES

OUTPUTS

A Description of Impacts . . .

OUTPUT: product of activities(# of health staff trained)

IMPACT: long term, high-level result (reduced transmission, reduced mortality)

OUTCOME: medium-term result (# tested, # on ART)

What does a PHIA Assess?

• The currents status of the epidemic in a country

• The access to and uptake of HIV care and treatment services

Scientific Rationale for PHIAs

Health facilities, and health facility access exists in a spectrum . . .

ART Site VCT/ANC Health Center

Pharmacy Limited/No Access

Current data is largely facility-based

Facility-based data describes a subset of the population

It is difficult to infer population measures– such as prevalence or incidence – from facility based data

Population-based surveys are the gold standard for these indicators

Summary: Scientific Rationale

Policy Rationale for PHIAs

4 million

Num

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El-Sadr WM et al 2012

Adults and children with HIV infection receiving ART with PEPFAR support, 2004-2011

2004 2011

Policy Rationale for PHIAs

After more than a decade of PEPFAR what is that status of the epidemic? For Example:• What is the rate of new infection following

prevention efforts?

• What is the proportion of Viral Load Suppression following expanded ART coverage?

Sampling for the PHIAsA Two-stage Cluster-based Sampling Strategy:

An example: What is the prevalence of coffee drinking at ICAP? Background: ICAP has 1000 staff, 20 Offices, 50 Staff/Office

A Census: Ask all 1000 ICAP staff if they drink coffee

A Simple Random Sample: Select 10, 100 or 500 ICAP staff and ask if they drink coffee

A Cluster-based Sample: Select 5 ICAP country offices, ask all staff in those offices if they drink coffee

A Two-stage Cluster-based Sample: Select 10 ICAP country offices, randomly select 25 people from each country office

Sampling for the PHIAsSampling Strategy:

• Using two-stage cluster-based sampling strategy– Sample ~500 Enumeration Areas (EA),stratified by health zone – Sample ~30 Households per EA

• Sample size includes ~15,000 HH; ~30,000 individuals

• Adults from every HH ~20,000, all children every other HH ~10,000

The DHS: A Pop Survey Celebrity

Similarities between DHS/PHIA

• Population-based household survey• Cross-sectional, nationally representative• Household and individual questionnaires• National and subnational HIV prevalence

estimates• Household and individual sample size similar

Differences between DHS & PHIA

• Biomarkers for CD4 counts, viral load, recency, drug resistance, ARV metabolites, peds

• Point-of-Care HIV testing and CD4 testing with return of results

• Opportunity to assess global HIV outcomes of interest that are outside domain of DHS– PMTCT – Potential for Treatment as Prevention

ICAP Experience with Pop Surveys• Swaziland HIV Incidence Measurement Survey • Sinazongwe Combination Prevention Evaluation

[SCOPE], in partnership with the Zambia MOH• Bukoba without New Infections, “Bukoba Bila

Maambukizi Mapya,” [BBM2] in Tanzania

Presentation Objective

MOH, CDC & ICAP’s Approach to Two PHIAs: Malawi and Zimbabwe

First Two PHIAs: Malawi and Zimbabwe

• In collaboration with CDC • Work with Ministries of Health to develop,

implement and disseminate findings from PHIA Pilots in Malawi in Zimbabwe

• From April 2014-March 2016• Currently in protocol development and pre-

implementation stage

Malawi• 16. 3 Million People

• Life expectancy: 54 Years

• Causes of Premature Mortality (YLL): HIV/AIDS (23.7%), Malaria (10%), Lower Respiratory Infection (9.7%)1

• HIV Prevalence (age 15-49)

• National: 10.3% 2

• HIV Care and Treatment:

• 675 ART sites, 470,000 patients on ART (83% of need)3

Malawi 2010 DHS.

1 Malawi Global Burden of Disease Study 2010; Institute for Health Metrics and Evaluation (IHME); 2 UNAIDS HIV and AIDS Estimates

3 UNGASS 2013 Malawi Country Progress Report

Zimbabwe• 13 Million People

• Life expectancy: 58 Years

• Causes of Premature Mortality (YLL): HIV/AIDS (29.0%), Lower respiratory infection (11.7%), Diarrheal disease (6.0%)1

• HIV Care and Treatment: 665,000 patients on ART (77% of need)2

Duri Kerina et al. HIV/AIDS: The Zimbabwean Situation and Trends. American Journal of Clinical Medicine Research, 2013, Vol. 1, No. 1.

1 Zimbabwe Global Burden of Disease Study 2010; Institute for Health Metrics and Evaluation (IHME); 2 UNGASS 2013 Zimbabwe Country Progress Report

Objectives for Malawi & Zimbabwe PHIAs

Primary Objectives:

• To estimate HIV incidence (i.e., prevalence of recent HIV infection) in a household-based, nationally representative sample of HIV-infected adults

• To estimate the sub-national prevalence of suppressed HIV viral load (<1000 cells/ml3) in a household-based, nationally representative sample of HIV-infected adults

Measuring Incidence LongitudinallyIncidence: new infections in a population

- --

---+-

January 1, 2014

= .25 cases per person year

January 1, 2015

Measuring Incidence Cross-Sectionally

2

1

Objective 1: IncidenceRecent infection (4-6 months) is identified by:

1) Low avidity - weak bonding strength between host antibody and virus.

2) An elevated level of HIV virus in the body

. . . And converted into an annualized rate

US HIV Incidence (06-09) = .02% Expected Zimbabwe/Malawi Incidence= ~1%

Objective 2: Viral Load Suppression (VLS)

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100 HIV Treatment Cascade

% o

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ith H

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Adapted from: aids.gov/federal-resources/policies/care-continuum/

Objectives for Malawi & Zimbabwe PHIAs

• To estimate HIV incidence (i.e., prevalence of recent HIV infection) in a household-based, nationally representative sample of HIV-infected adults

• To estimate the sub-national prevalence of suppressed HIV viral load (<1000 cells/ml3) in a household-based, nationally representative sample of HIV-infected adults

Objectives for Malawi & Zimbabwe PHIAs

Secondary Objectives:

• HIV prevalence in adults and children• CD4 T-Cell counts• Transmitted drug resistance • ARV metabolites• Nutrition in HIV positive children• HIV-related risk behaviors • Use of HIV-related services• HIV knowledge and attitudes

Similarities in Malawi and Zimbabwe PHIAs

Objectives:• Incidence (national), Viral Load Suppression (zonal)

Eligibility Criteria:• Must be a HH member

– resides or slept night before in HH• Must give informed consent• All adults in every household• All children (ages 0-14) in every other household

Similarities in Malawi and Zimbabwe PHIAs

Survey Procedures: • Collect questionnaire data and blood samples • Carry out POC HIV and CD4 testing• Provide counseling and return results• Refer HIV positives to care• Transport blood samples to central lab for

additional testing

Similarities in Malawi and Zimbabwe PHIAs

Questionnaires:• Household Questionnaire • Adult Individual Questionnaire

– Demographics including marriage– HIV knowledge and attitudes– Reproduction– Sexual history– HIV testing, care and treatment history

Similarities in Malawi and Zimbabwe PHIAs

Data Management: • Tablets Cloud server in-country server

Laboratory Management:• Central level testing at a national lab (VL, EID, recency)

Country Oversight Mechanism:• TWG chaired by MOH • Sub-committees on Management, Protocol, Data,

Communications

Unique to Malawi PHIA

• Oversampling of high prevalence health zones – for greater precision around cascade analysis– interest in making programmatic

assessments/comparisons in future rounds

• Sample will include adults aged 15-64

Unique to ZIMPHIASecondary Objectives:• Prevalence of Syphilis• Describing the extent of stigma

Sampling:• Sample will include all adults over 15

Questionnaire:• Module for adolescents aged 10-14

Presentation Objective

The Future of PHIAs:The PHIA Project

On the Horizon: ‘the next 20’In collaboration with CDC and MOHs , ICAP will

conduct PHIAs in ~20 sub-Saharan African countries over the next 5 years

• No country list yet

Focus on building capacity for population-based surveys • Strengthen capacity in epidemiology, surveillance, statistics

and national reference laboratory services to collect, analyze, and use morbidity and mortality data

On the Horizon: ‘the next 20’• Partnerships with experienced groups:

– UCSF (KAIS), ICF (DHS), Westat (NHANES), SCHARP (e.g., HPTN/MTN/VTN and SHIMS) and ASLM

• Approach for high prevalence countries may differ for low prevalence countries

• Use results to assess impact of PEPFAR and guide policies and future programs

Key Messages• ICAP’s PHIAs are Population-based HIV Impact

Assessments

• Rigorously measure key indicators of the epidemic such as• Incidence• Viral Load Suppression

Key Messages• They will provide information on HIV program

effectiveness that can be used to inform future programs and policies

• The first two PHIAs will be in Malawi and Zimbabwe

• ICAP will work on ~20 PHIAs over the next 5 years

Acknowledgements

• The Governments of Malawi & Zimbabwe• United States Centers for Disease Control and

Prevention• The U.S. President’s Emergency Plan for AIDS

Relief (PEPFAR)• Padmaja Patnaik, Suzue Saito, Jessica Justman• The PHIA Team

Zikomo, Tatenda, Thank you!