A hospital wants to know how common diabetic nephropathy is in the general population of persons with type 2 diabetes. Kidney biopsy samples are collected from 500 adult diabetic patients receiving medical treatment. The samples are then analyzed by ten different pathologists, five of whom work at the hospital and five at surrounding institutes. According to early findings, pathologists who work for the hospital are three times more likely than those who do not work for the hospital to interpret biopsy samples as diabetic nephropathy. Which of the following is the most plausible explanation for this discrepancy in interpretation?

Question

Quizplus · Accepted Answer

Eductional Objective: Observer bias (also known as expectancy bias) arises when researchers misclassify data as a result of predetermined expectations or prior information about the study or its participants. This form of bias is especially significant when the outcomes are subjective (ie, involve personal interpretation of clinical, microscopic, or radiographic findings).
Pathologists at the hospital where the study is being done may be aware that the study is looking at diabetic nephropathy, or they may have access to extra medical records indicating diabetes status. Pathologists at other institutions, on the other hand, are more likely to be oblivious to the study's aims and the patients' medical histories.

A Hospital Wants to Know How Common Diabetic Nephropathy Is