American Board of Surgery Qualifying Exam (ABS QE) Practice Test

What is the cause of non-response bias?

1. Individuals changing their responses

2. Individuals refusing to participate

3. Misclassification of data

4. Sampling errors in selection

The correct answer is: Individuals refusing to participate

Non-response bias occurs when individuals who choose not to participate in a survey or study differ in meaningful ways from those who do respond. This can lead to a situation where the final sample is not representative of the broader population, affecting the validity and reliability of the results. The individuals who refuse to participate may have particular characteristics, attitudes, or experiences that differ significantly from those who participate, which skews the data. For instance, if a survey about healthcare access is sent out, and those who decline to respond tend to be from lower socioeconomic backgrounds, their absence may lead to an underestimation of the challenges faced by that demographic, ultimately distorting the findings. The other factors listed influence data quality in different ways but do not directly cause non-response bias. For example, individuals changing their responses can create data inconsistencies but does not inherently lead to the neglect of particular segments of the population. Misclassification of data pertains to errors in categorizing responses and doesn’t relate to who participates. Sampling errors occur during the selection of participants but are distinct from the issue of individuals not responding.