RESEARCH ARTICLE
A Probability Sample for Monitoring the HIV-infected Population in Care in the U.S. and in Selected States
Martin R Frankel1, AD McNaghten*, 2, Martin F Shapiro 3, 4, Patrick S Sullivan 5, Sandra H Berry 3, Christopher H Johnson 2, Elaine W Flagg 2, Sally Morton 6, Samuel A Bozzette 3, 7
Article Information
Identifiers and Pagination:
Year: 2012Volume: 6
Issue: Suppl 1
First Page: 67
Last Page: 76
Publisher ID: TOAIDJ-6-67
DOI: 10.2174/1874613601206010067
Article History:
Received Date: 15/4/2011Revision Received Date: 22/8/2011
Acceptance Date: 14/9/2011
Electronic publication date: 7/9/2012
Collection year: 2012

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.
Abstract
Epidemiologic and clinical changes in the HIV epidemic over time have presented a challenge to public health surveillance to monitor behavioral and clinical factors that affect disease progression and HIV transmission. The Medical Monitoring Project (MMP) is a supplemental surveillance project designed to provide representative, population-based data on clinical status, care, outcomes, and behaviors of HIV-infected persons receiving care at the national level. We describe a three-stage probability sampling method that provides both nationally and state-level representative estimates.
In stage-I, 20 states, which included 6 separately funded cities/counties, were selected using probability proportional to size (PPS) sampling. PPS sampling was also used in stage-II to select facilities for participation in each of the 26 funded areas. In stage-III, patients were randomly selected from sampled facilities in a manner that maximized the possibility of having overall equal selection probabilities for every patient in the state or city/county. The sampling methods for MMP could be adapted to other research projects at national or sub-national levels to monitor populations of interest or evaluate outcomes and care for a range of specific diseases or conditions.