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Flashcards in Biostatistics Deck (9)
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1

Confounding

a 3rd variable that hasn't been considered but muddies the exposure & outcome bc is is related to both
i.e. (EtOH & bladder cancer seem associated until you realized smoking & bladder cancer are assoc. and smokers are more likely to drink)

2

Lead-time Bias

Artificial increase in pt survival time who actually have an unchanged prognosis, when in reality they were just diagnosed earlier

3

T-test

compares the mean of 2 groups of subjects

4

Chi-square test

compares the mean of >/= 3 groups; categorical data

5

Correlation Coefficient

0= no correlation, 1= perfect correlation, -1= perfectly inverse correlation

6

Positively Skewed Distribution

Mean > Median > Mode

7

Negatively Skewed Distribution

Mean

8

Hawthorne Effect

subjects change behavior when they find out they are being studied

9

Pygmalian Effect

Bias based on investigator bias and the inability to see the results in an unbiased manner