Komro K A, Kelder S H, Perry C L, Klepp K I
University of Minnesota, School of Public Health, Division of Epidemiology, Minneapolis 55454-1015.
Prev Med. 1993 Nov;22(6):857-65. doi: 10.1006/pmed.1993.1077.
Two strategies to resolve the problem of under- or overreporting of tobacco use among adolescents have been utilized: (a) objective measures for validating self-reports and (b) procedures for improving validity of self-reports, such as the pipeline procedure. The objectives of this article are to investigate the hypothesis that reporting biases may be related to intervention status and to examine what effect such biases would have on interpretation of treatment effects.
A two-by-two factorial design was used, with the first factor a pipeline manipulation consisting of pipeline versus control condition, and the second factor treatment status, consisting of treatment versus reference schools. Within each of the schools, half of the 9th-grade classrooms were randomly assigned to a pipeline condition and half served as controls. Analysis was conducted with school as the unit of analysis.
The main effect for pipeline condition and the significant interaction between treatment and pipeline conditions were not significant. However, the pipeline manipulation did have an effect on the difference detected between treatment and reference schools; 4.3% difference between treatment and reference schools in the control condition versus 9.9% difference in the pipeline condition, both in the direction of a treatment effect. Using saliva thiocyanate as an objective measure of smoking status suggested differential false negative reporting where students in the reference community falsely claimed to be nonsmokers more frequently than in the treatment community (10.04% versus 5.96%).
The reporting bias assessed by the pipeline procedure alone appears to have masked treatment outcome effects. Adjusting the smoking-dependent variable for false negatives seems to have increased the treatment outcome effects even further. This result is contrary to the expectation that the treatment community would experience greater demand pressures to underreport their smoking behavior. Further investigation to address response biases in intervention studies is warranted.
已采用两种策略来解决青少年烟草使用报告不足或过度报告的问题：（a）用于验证自我报告的客观测量方法，以及（b）提高自我报告有效性的程序，如管道程序。本文的目的是研究报告偏差可能与干预状态相关的假设，并检验这种偏差对治疗效果解释的影响。
采用二乘二析因设计，第一个因素是管道操作，包括管道条件与对照条件，第二个因素是治疗状态，包括治疗学校与参照学校。在每所学校内，九年级教室的一半被随机分配到管道条件组，另一半作为对照组。以学校为分析单位进行分析。
管道条件的主效应以及治疗与管道条件之间的显著交互作用均不显著。然而，管道操作确实对治疗学校与参照学校之间检测到的差异产生了影响；在对照条件下，治疗学校与参照学校之间的差异为4.3%，而在管道条件下为9.9%，两者均呈治疗效果方向。使用唾液硫氰酸盐作为吸烟状态的客观测量方法表明存在不同的假阴性报告，即参照社区的学生比治疗社区的学生更频繁地虚假声称自己不吸烟（10.04%对5.96%）。
仅通过管道程序评估的报告偏差似乎掩盖了治疗结果效应。针对假阴性对吸烟相关变量进行调整似乎进一步增强了治疗结果效应。这一结果与预期相反，即治疗社区在低报吸烟行为方面会面临更大的需求压力。有必要进一步调查以解决干预研究中的反应偏差问题。
