Shiono P H, Klebanoff M A
Center for the Future of Children, David and Lucile Packard Foundation, Los Altos, CA.
Am J Epidemiol. 1991 Sep 1;134(5):539-42. doi: 10.1093/oxfordjournals.aje.a116126.
In 1989, the authors tested the effectiveness of two response-enhancing techniques, a postage stamped or franked return envelope and a prenotification letter, in a survey of pregnancy among 10,047 resident physicians in the United States. The techniques were randomly assigned using a factorial design. No significant interactions were observed between the techniques. After two mailings, those who received a stamped return envelope had a response of 71.2%, compared with 68.2% for those who received a franked return envelope (95% confidence interval 1.3-4.9%). Men who received the stamped envelope had a 5.9% greater response than those who received the franked envelope (p less than 0.001), but the type of postage did not influence response among women (p = 0.84); this interaction was statistically significant (p = 0.006). Physicians who received a prenotification letter had a response of 69.0%, compared with 70.5% for those who did not receive the letter (95% confidence interval -3.3 to 0.2%). The authors conclude that seemingly minor changes in survey design could have saved from 12% to 19% of the total cost of the study.
1989年，作者在美国对10,047名住院医师进行的一项妊娠调查中，测试了两种提高回复率的技巧的有效性，即使用贴有邮票或盖有邮戳的回邮信封以及预先通知信。这些技巧采用析因设计进行随机分配。未观察到这些技巧之间存在显著的交互作用。经过两次邮寄后，收到贴有邮票回邮信封的人的回复率为71.2%，而收到盖有邮戳回邮信封的人的回复率为68.2%（95%置信区间为1.3 - 4.9%）。收到贴有邮票信封的男性的回复率比收到盖有邮戳信封的男性高5.9%（p小于0.001），但邮资类型对女性的回复率没有影响（p = 0.84）；这种交互作用具有统计学意义（p = 0.006）。收到预先通知信的医师的回复率为69.0%，而未收到该信的医师的回复率为70.5%（95%置信区间为 -3.3至0.2%）。作者得出结论，调查设计中看似微小的变化可能使研究总成本节省12%至19%。
