Biostatistics — Flashcards

Flashcard 131: Relative or Standard Normal Deviate or Variate (Z) _____

Answer: \(Z = \frac {Observation - Mean}{SD}\)

Extra: y

Flashcard 132: For small samples, to calculate significance of difference between means, t-test is applied → To compare the mean of a single group of observations with a specified value, _____ is done → \(t = \) _____ → Obtained value is compared to t-value given for given degree of freedom (_____) and significance level (corresponding p-value) from table → If t-value obtained > given t-value, then the difference is said to be statistically _____

Answer: One sample t-test

Extra:  y

Flashcard 133: diagnostic capacity of a test is given by _____

Answer: positive predictive value

Extra: 

Flashcard 134: c65872b736324b578b20a22eef5c027a-ao-1

Answer: tests of significance

Extra: 

Flashcard 135: _____ predictive value varies inversely with pretest probability

Answer: Negative

Flashcard 136: Bar graphs can be used for representing _____ scale data that forms discrete categories

Answer: ordinal/nominal

Flashcard 137: When lowering the cutoff point for a disease, the _____ and PPV will decrease

Answer: specificity

Flashcard 138: _____ is least affected by outliers but mean is the most affected out of all the measures of location.

Answer: Mode

Flashcard 139: _____ = (1 - sensitivity) / specificity

Answer: Negative likelihood ratio

Flashcard 140: Randomization can be done in a blocked manner where randomization is done within _____ in order to ensure equal balance in number of treatment and control subjects throughout the study

Answer: blocks of 4-8 subjects