School of Public Health, Jonsson Comprehensive Cancer Center, University of California, Los Angeles, CA 90095-6900, USA.
Prev Med. 2011 Feb;52(2):167-73. doi: 10.1016/j.ypmed.2010.11.007. Epub 2010 Nov 25.
Understanding mediators for behavioral change is important for the optimization of intervention strategies. This report examines mediators of change in the context of a randomized controlled intervention trial (Los Angeles, 2004-2009) that successfully increased colorectal cancer (CRC) screening among Filipino Americans.
The intervention, based on the Health Behavior Framework, targeted knowledge/awareness of CRC screening, communication with health care provider, health beliefs, social support and barriers to CRC screening. Health Behavior Framework variables were assessed at baseline and 6-month follow-up (N=432). Variables targeted for change were tested as potential mediators of the primary outcome, self-reported receipt of CRC screening during the follow-up period, which was previously found to have increased significantly among intervention participants.
Consistent with the Health Behavior Framework, knowledge/awareness of CRC screening and patient-provider communication mediated receipt of screening. Increase in knowledge/awareness of CRC screening accounted for 13% (95% confidence interval 2%-24%) of the total intervention effect size, while patient-provider communication accounted for 20% (5%-36%). Combined, these two variables accounted for 28% (10%-46%) of the total effect size.
Examining the roles of potential mediators in intervention trials may help identify constructs to target in order to enhance the effectiveness of interventions to increase screening.
了解行为改变的中介因素对于优化干预策略非常重要。本报告考察了在一项成功提高菲律宾裔美国人结直肠癌（CRC）筛查率的随机对照干预试验（2004-2009 年，洛杉矶）背景下的变化中介因素。
该干预措施基于健康行为框架，针对 CRC 筛查的知识/意识、与医疗保健提供者的沟通、健康信念、社会支持和 CRC 筛查障碍。在基线和 6 个月随访时评估健康行为框架变量（N=432）。针对变化的变量被测试为主要结果（自我报告在随访期间接受 CRC 筛查）的潜在中介因素，先前发现干预组中该结果显著增加。
与健康行为框架一致，CRC 筛查知识/意识和医患沟通介导了筛查的接受。CRC 筛查知识/意识的增加占干预效果大小的 13%（95%置信区间 2%-24%），而医患沟通占 20%（5%-36%）。这两个变量加起来占总效果大小的 28%（10%-46%）。
在干预试验中检查潜在中介因素的作用，可能有助于确定要针对的构建模块，以提高增加筛查的干预措施的有效性。
