Bunin Greta R, Spector Logan G, Olshan Andrew F, Robison Leslie L, Roesler Michelle, Grufferman Seymour, Shu Xiao-ou, Ross Julie A
Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.
Am J Epidemiol. 2007 Jul 1;166(1):109-16. doi: 10.1093/aje/kwm050. Epub 2007 Apr 23.
Since the mid-1990s, epidemiologists have anecdotally reported difficulty in recruiting controls using random digit dialing (RDD), but few empirical data have been published. From 1982 to 2003, epidemiologists from the Children's Oncology Group conducted 17 case-control studies using RDD controls. Data for calculating RDD and field response rates were available from eight and 13 of these studies, respectively. Over the period of analysis, the contact rate declined 2.5% per year (95% confidence interval (CI): -3.4, -1.6; p = 0.001), from above 90% in the 1980s to 63-69% in the most recent studies. The response rate (the product of the contact and cooperation rates) showed a decline parallel to that of the contact rate (-2.4% per year, 95% CI: -3.2, -1.6; p < 0.001), from above 80% in the 1980s to 50-67% after the mid-1990s. Field response rates appeared to have declined modestly. The overall response rate (the product of the RDD response and field response rates) paralleled that of the RDD response rate and decreased 2.4% per year (95% CI: -2.7, -2.0; p < 0.001). The current low response rates for RDD indicate a substantial potential for selection bias and a need to seek alternative sources of controls.
自20世纪90年代中期以来，流行病学家一直有传闻称，使用随机数字拨号（RDD）招募对照存在困难，但很少有实证数据发表。1982年至2003年，儿童肿瘤研究组的流行病学家进行了17项使用RDD对照的病例对照研究。分别有8项和13项研究可获得计算RDD和现场应答率的数据。在分析期间，接触率每年下降2.5%（95%置信区间（CI）：-3.4，-1.6；p = 0.001），从20世纪80年代的90%以上降至最近研究中的63%-69%。应答率（接触率与合作率的乘积）显示出与接触率平行的下降趋势（每年-2.4%，95%CI：-3.2，-1.6；p < 0.001），从20世纪80年代的80%以上降至20世纪90年代中期后的50%-67%。现场应答率似乎略有下降。总体应答率（RDD应答率与现场应答率的乘积）与RDD应答率平行，每年下降2.4%（95%CI：-2.7，-2.0；p < 0.001）。目前RDD的低应答率表明存在选择偏倚的巨大可能性，需要寻找替代的对照来源。
