Flashcards
Bias and miscalssification
Cards in this deck (24)
- 13 aspects evaluated before declaring a real, true associationcheck for confounding or effect modification
check for bias
check for statistical significance - 2definition of biasSystematic/non-random error in study design or conduct leading to erroneous results
- 3bias distortsrelationship/association between exposure and outcome
- 4can a bias be fixed if it has already occuredNO
- 5what can minimize bias and impact?prospective/prestudy consideration and adjustment
- 63 elements of bias impactsource/type
magnitude/strength
direction - 7Selection related biasany aspect in the way the researcher selects or aquires study subjects, creating a systematic difference between groups
- 8Healthy worker biasSelection bias
the healthy people are the available study subjects, sick people wont come to work and may not be considered for study - 9Self-selection/participant (Responder) biasSelection bias
Those self-selecting, avoiding the clipboard person, unhealthy people may not want to participate - 10Measurement bias (information/observer)any aspect in the way the researcher collects information or measures/observes subjects which creates a systematic difference between groups
- 11Recall/reporting biasMeasurement bias
a differential level of accuracy/detail in provided information between study groups
exposed/diseased patients may remember better or exaggerate or amplify their response - 12Contamination biasMeasurement bias
members of the control group accidentally or outside of the study receive treatment or similar or are exposed to the intervention being treated - 13compliance/adherence biasMeasurement bias
how well the patients listen and comply to the instruction, worry about one group not complying different from another - 14Hawthorn effectbecause the study is happening, the study subjects change their behavior
- 15Lost to follow up biasmeasurement bias
die, stop complying, move out of town. patients do not finish. worry about one group quitting more than the other, something has changes significantly - 16Interviewer/proficiency biassystematic difference in soliciting, recording, or interpreting on the part of the researcher or assistants. tone of voice, questions, influencing responses from study subjects. can be conscious or unconsious
- 17diagnosis/surveillance/expectation biasmeasurement bias
Different evaluation, classification, diagnosis, or observation between groups. observers may have preconceived expectations of what they should find in examination
hawthorne-like effect from researchers perspective - 18lead-time biasan apparent benefit from a healthcare screening d/t early detection of disease
extra-time knowing they have the disease and treatment, increases life duration - 19how to avoid interviewer biasipad/computer
no voice inflections or body language to watch for
no unplanned follow up questions
all standardized
pts. wont ask questions - 20misclassification biaserror in classifying either disease or exposure status or both
- 21Non-differential biaserror in both groups equally
misclassification of exposure or disease
both are equally wrong
acceptable problem/bias - 22Differential biaserror in classifying one group more than the other, going to move it further away from one, totally skew results
- 23Blinding/maskinghide groups from researchers
- 24Randomly allocate observers/interiewersmake sure questions are always being asked the same way
electronics are a goodway to control for this
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- Epidemiology Flashcards on Bias and miscalssification, created by Alexis Bartschi on 20/10/2017.
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- Alexis Bartschi
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