6. Time – Location Sampling

This course aims to provide participants with practical skills and knowledge to implement a population-based bio-behavioural survey using Time Location Sampling (TLS).  TLS is a widely used method to sample populations that are socialising at outdoor venues, such as men who have sex with men in bars, truck drivers at bus stops, sex workers in parks and on streets etc. In TLS, a primary-sampling unit is defined as the combination of the site and the time, and the same site may be included in the sampling frame more than once, at different times of the day or a week.  It has been used to sample different high risk groups and results have been described in the literature.

 

Learning objectives

The course will describe the requirements, principles and design of survey which use TLS in a variety of field contexts. Presenters will describe all the steps necessary for organising and implementing a TLS survey.  Important issues to be covered include conducting mapping and development of a sampling frame and randomization, establishing collaboration with  communities at risk, selection of venues for inclusion in the sampling frame, organization of the study, enumeration, screening participants for eligibility, roles and responsibilities of staff, data management and documentation and collection of biological and behavioral data. Weighting of TLS data will be discussed and demonstrated in STATA. Furthermore, this course provides field examples of the advantages and challenges associated with implementing TLS and provide contingency plans for dealing with difficult and unforeseen problems in the field.

 

Key topics

• When to implement time-location sampling
• How to do mapping, randomization and sampling calendar
• Enumeration and recruitment into the survey
• Study design issues in time-location sampling
• Team composition
• Study documentation and duration of the survey
• Transfer of data, weighting and data analysis
• HIV and STI tests
• ​​​Advantages and disadvantages of time-location sampling

 

Teaching Methods

The course consists of lectures, exercises and a design of a surveillance protocol based on time-location sampling. Exercises will include practicing randomization of venues selected into the sampling frame, enumeration and recruitment of participants in the survey. 

 

Target Audience

Participants may include epidemiologists, statisticians and HIV programme managers who work on HIV surveillance. High-level statistical or epidemiological training is not a prerequisite.

 

Duration

The course takes place in five days.

 

Partners

San Francisco Department for Public Health

 

This course was held in:

•  Zagreb, Croatia
•  Baku, Azerbaijan