Wednesday 16 October 2019

M21: Population Size Estimations in Key Populations: Methods and Lessons Learned around the World


Establishing the size of various populations at risk for HIV has been identified as one of the greatest challenges in HIV surveillance and in developing estimates of HIV prevalence and incidence. Reliable estimates of the size of populations at high risk for HIV are important for prioritizing target populations, planning HIV prevention services, measuring coverage with these services and monitoring and evaluation of interventions. Credible estimates of population size contribute to documenting progress in HIV prevention scale-up and in obtaining continued funding for the provision of various services.

The aim of the course is to provide participants with practical guidance on how to design studies to estimate the size of populations at higher risk for HIV (particularly female sex workers [FSW], people who inject drugs [PWID], men who have sex with men [MSM]), conduct these studies, and analyze, interpret and use the data. The course will provide examples of lessons learned around the world in implementation of size estimates studies and challenges in interpretation of various data sources. 

Key topics of the course are:

  • Methods of population size estimates: census, enumeration and mapping; multiplier method; surveys; capture-recapture; network scale-up
  • Interpreting diverging results of the size estimates studies
  • Using data for national size estimations
  • Calculating indicators of coverage with HIV prevention based on the size estimation data
  • Designing size estimates studies and writing-up results

 Objectives of the course are the following:

  • To understand the importance and uses of size estimation data
  • To build skills in using methods and field procedures for size estimation
  • To learn how to use multiple data sources to develop size estimates
  • To develop protocols for conducting size estimation studies and the use of size estimation information for programme development

Participants will be given an opportunity to share their own country-specific experiences and challenges in estimating the size of high-risk groups. Participants will also develop draft protocols for size estimation studies which they can later on use in their countries.

Teaching Methods

The course consists of lectures, presentation of case studies, active class discussion, exercises and group work. The course is designed to provide participants with practical skills and knowledge on how to conduct size estimation studies. 

Target Audience

Epidemiologists, demographers, public health professionals, social scientists.


  • Ivana Bozicevic, MD, DrPH, WHO Collaborating Centre for HIV Surveillance, School of Medicine, University of Zagreb, Croatia
  • Jurja-Ivana Cakalo, MD, WHO Collaborating Centre for HIV Surveillance, School of Medicine, University of Zagreb, Croatia
  • Zoran Dominkovic, WHO Collaborating Centre for HIV Surveillance, School of Medicine, University of Zagreb, Croatia

Course organiser:

Lucija Sikic, University of Zagreb School of Medicine                                                                                                                                                                                                                                      

The course is held at:

WHO Collaborating Centre for HIV Surveillance
Andrija Stampar School of Public Health
University of Zagreb School of Medicine
Rockefellerova 4
10000 Zagreb
Phone: +385 1 4590 142 / 4590 100
Fax: +385 1 46 84 212

The course fee is 950 USD and includes training materials and lunch and coffee/tea breaks during the course.


Download the Programme

Programme Population Size Estimates May 2016.doc

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