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PARTICIPANT RECRUITMENT AND RETENTION FOR THE NERL RTP PM PANEL STUDY
Citation:
Leovic, K W., R W. Williams, A. Ejire, W. Sanders Jr., J. Thornburg, AND C. E. Rodes. PARTICIPANT RECRUITMENT AND RETENTION FOR THE NERL RTP PM PANEL STUDY. Presented at 11th Annual Meeting of the International Society of Exposure Analysis, Charleston, SC, November 4-8, 2001.
Impact/Purpose:
The primary study objective is to quantify the association(s) between day-to-day or experimental variations in ambient air particle mass concentrations and selected physiological functions in elderly persons living in a retirement centers or involved in selected clinical studies. The NERL will conduct exposure studies and provide real-time and integrated PM mass concentration and selected criteria pollutant data to assist the NHEERL collaborators conducting physiological monitoring in establishing selected health effect associations resulting from potential human exposures to PM-related air pollutants.
Description:
EPA's National Exposure Research Laboratory (NERL) completed a 12 month Particulate Matter (PM) Panel Study in the Research Triangle Park, NC area in May 2001. A primary goal of the study was to compare PM levels measured at an ambient and residential sites with those from personal exposure monitors. The study included two cohorts: 1) 27 African-Americans with controlled high blood pressure living in Southeast Raleigh, and 2) 8 cardiac patients who have an implanted cardiac defibrilator. All 35 participants were at least 50 years old and non-smokers. The study was conducted over four consecutive seasons for 7-days each season for a total of 28 days. Each day of the study, participants were required to wear active and passive personal monitors weighing almost 1,800g attached to a vest, have monitors placed indoors/outdoors at their residences, and complete a time-activity diary. Each participant was compensated $10/day, plus $5/day for electricity and $20 bonus for 26+ days (max of $440). The participant recruitment/retention target was for 30 participants completing at least three of the four seasons. Participant retention was essential for the study's longitudinal component to be successful.
To recruit the 27 African-Americans, we collaborated with Shaw University (a historically black university) on community outreach; letters of support were received from community organizations and leaders; the local media (e.g., NC's African-American newspaper, Raleigh's daily newspaper, TV, community and university radio stations) were informed ; Southeast Raleigh churches, community organizations (Wake County Human Services, Strengthening the Black Family, Triangle Family Services, Raleigh area NAACP) were contacted; Shaw University and EPA employees were informed; and flyers were distributed in the community. In the second season, two replacement participants were recruited for the African-American cohort. The eight cardiac patients were recommended by their physician at the University of North Carolina-Chapel Hill and were recruited by direct mailings and follow up phone calls. Research Triangle Institute (RTI) performed the field measurements.
Based on participant feedback, a key factor in participant retainment was their very positive interaction with the RTI Field Team throughout the study. Additional activities to promote retention included continued community outreach in Southeast Raleigh by Shaw University; providing framed certificates, personal letters, and phone calls from the Principle Investigator; holding quarterly participant meetings to promote "group camaraderie" and encourage participant feedback; providing study results quarterly based on participant input; and sending quarterly newsletters. A total of 28 participants completed at least three of four seasons: 21 of the 29 African-American participants (27 plus two replacements) and seven of the eight cardiac participants. Thus, 93% of the study target of 30 participants completed at least three of four seasons.
Reasons for participant dropout from the study were unrelated health problems (3), scheduling or time problems (2), loss of interest (2), and inability to avoid second-hand smoke (1).
This work has been funded wholly by the U.S. EPA under assistance agreement #CR-828186-01-0 to Shaw University and contract 68-D-99-012 to the Research Triangle Institute. It has been subjected to Agency review and approved for publication.