Substitution game bias Substitution of the clinically important endpoint, or an exposure, with a surrogate marker for the disease. Read More
Unacceptability bias A systematic difference in response rates or uptake of tests due to their “unacceptability” Read More
Unacceptable disease bias Lower rates of reporting of certain “unacceptable” diseases compared with other health conditions. Read More
Unmasking (detection signal) bias An innocent exposure that, rather than causing a disease, causes a sign or symptom that precipitates a search for the disease. Read More
Verification bias when only a proportion of the study group receives confirmation of the diagnosis by the reference standard, or if some patients receive a different reference standard at the time of diagnosis. Read More
Volunteer bias Participants volunteering to take part in a study intrinsically have different characteristics from the general population of interest. Read More
Wrong sample size bias When the wrong sample size is used in a study: small sample sizes often lead to chance findings, while large sample sizes are often statistically significant but not clinically relevant. Read More
