DeVita Deborah A, White Mary C, Zhao Xin, Kaidarova Zhanna, Murphy Edward L
Department of Laboratory Medicine, University of California, San Francisco, California, USA.
BMC Med Res Methodol. 2009 Mar 10;9:19. doi: 10.1186/1471-2288-9-19.
Understanding participation in a prospective study is crucial to maintaining and improving retention rates. In 1990-92, following attempted blood donation at five blood centers, we enrolled 155 HTLV-I, 387 HTLV-II and 799 HTLV seronegative persons in a long-term prospective cohort.
Health questionnaires and physical exams were administered at enrollment and 2-year intervals through 2004. To examine factors influencing attendance at study visits of the cohort participants we calculated odds ratios (ORs) with generalized estimated equations (GEE) to analyze fixed and time-varying predictors of study visit participation.
There were significant independent associations between better visit attendance and female gender (OR = 1.31), graduate education (OR = 1.86) and income > $75,000 (OR = 2.68). Participants at two centers (OR = 0.47, 0.67) and of Black race/ethnicity (OR = 0.61) were less likely to continue. Higher subject reimbursement for interview was associated with better visit attendance (OR = 1.84 for $25 vs. $10). None of the health related variables (HTLV status, perceived health status and referral to specialty diagnostic exam for potential adverse health outcomes) significantly affected participation after controlling for demographic variables.
Increasing and maintaining participation by minority and lower socioeconomic status participants is an ongoing challenge in the study of chronic disease outcomes. Future studies should include methods to evaluate attrition and retention, in addition to primary study outcomes, including qualitative analysis of reasons for participation or withdrawal.
了解参与前瞻性研究的情况对于维持和提高保留率至关重要。1990 - 1992年，在五个血液中心尝试献血后，我们招募了155名HTLV - I感染者、387名HTLV - II感染者和799名HTLV血清学阴性者进入一个长期前瞻性队列。
在入组时以及至2004年每两年进行一次健康问卷调查和体格检查。为了研究影响队列参与者参加研究访视的因素，我们使用广义估计方程（GEE）计算比值比（OR），以分析研究访视参与的固定预测因素和随时间变化的预测因素。
更好的访视出勤率与女性性别（OR = 1.31）、研究生学历（OR = 1.86）和收入>75,000美元（OR = 2.68）之间存在显著的独立关联。来自两个中心的参与者（OR = 0.47, 0.67）以及黑人种族/族裔的参与者（OR = 0.61）继续参与的可能性较小。更高的访谈受试者报酬与更好的访视出勤率相关（25美元报酬对比10美元报酬时，OR = 1.84）。在控制人口统计学变量后，没有任何与健康相关的变量（HTLV状态、自我感知健康状况以及因潜在不良健康结果而转诊至专科诊断检查）对参与情况有显著影响。
在慢性病结局研究中，增加和维持少数群体以及社会经济地位较低参与者的参与度是一项持续的挑战。未来的研究除了主要研究结局外，还应包括评估失访和保留情况的方法，包括对参与或退出原因的定性分析。
