What is selection bias?
When selected sample is not a representative sample of reference population.
What is loss to follow up bias?
Occurs in cohort studies when follow up cases are lost continuously, leading to an unrepresentative sample.
What is disease spectrum bias also known as?
Case-mix bias.
What happens in disease spectrum bias?
Occurs when a treatment is studied in more severe forms of a disease, which may not apply to mild forms.
Define sampling bias.
When the subjects are not representative of the population due to factors like volunteer bias.
What is volunteer bias?
Occurs when individuals at risk are more or less likely to participate in a study.
What is participation bias also known as?
Non-response bias.
What is incidence-prevalence bias?
Occurs in case-control studies due to selective survival among prevalent cases.
What is exclusion bias?
Occurs when certain patients are excluded from a study due to ineligibility.
What is publication bias?
Many studies may not be published, often due to positive results being more likely to be published.
Define citation bias.
Articles with high citation are more likely to be included in studies.
What is Berkson’s bias?
A type of selection bias arising from sampling a subpopulation rather than the general population.
What is information bias?
When gathered information about exposure, outcome, or both is incorrect due to measurement error.
What is detection bias?
Occurs when exposure influences diagnosis, potentially skewing results.
What is recall bias?
In retrospective studies, cases may remember risk factors better than controls, skewing results.
What is lead time bias?
The period between early detection of a disease and its usual clinical presentation, which can distort survival data.
What is interviewer/observer bias?
Occurs when the knowledge of the interviewer affects data collection and registry.
What is verification and work-up bias?
Occurs when the results of a diagnostic test affect whether a gold standard procedure is used.
What is the Hawthorn effect?
Participants alter their behavior because they are aware they are being studied.
What is ecological fallacy?
Conclusions about individuals based only on group data analysis.
What is expectation bias also known as?
Pygmalion effect.
What is late-look bias?
Gathering information at an inappropriate time, such as studying a fatal disease after many patients have died.
