Biostatistics — Flashcards

Flashcard 31: Sample size calculation for qualitative data, when proportions are given \(p = positive \ character\ in \ \%\) \(q= negative\ character\ in\ \% (100-p) \) \(L = allowable \ error, \ usually \ 10 \% \ or \ 20\% \ of \ p\) is given by _____

Answer: \(n = \frac {4pq}{L^2}\)

Flashcard 32: global annual growth rate is _____%

Answer: 1.07

Extra: 

Flashcard 33: null hypothesis is _____ if p value is >0.05

Answer: accepted

Extra: 

Flashcard 34: Formula for Mean (assumed mean method) for Ungrouped data: When individual observations are large in size, we take \(w\) as the assumed mean. The mean of deviations from the assumed mean is denoted by \(\bar{d}\): _____ The actual Mean \(\bar{X}\) is then calculated by: _____

Answer: \(\bar{d} = \frac{\sum (X_i - w)}{n}\)

Flashcard 35: bar chart is used for plotting _____ data

Answer: qualitative

Extra: 

Flashcard 36: Formula for **Median** when the total number of observations (*n*) is **even**: Median = _____{2}\)}}

Answer: \(\frac{(\frac{n}{2})^{th}\text{ term} + (\frac{n}{2}+1)^{th}\text{ term

Flashcard 37: _____ error is more serious than false negative (Type II) error

Answer: False positive (Type I)

Extra: Type I error (α): False positive - Rejecting the null hypothesis when it is true. Type II error (β): False negative - Failing to reject the null hypothesis when it is false. In statistical hypothesis testing, Type I error is generally considered more serious because it leads to the claim of an effect or difference that does not exist (potentially leading to the adoption of ineffective or harmful treatments).

Flashcard 38: In Biostatistics (PSM), **regression** is primarily used for _____

Answer: prediction

Extra: Correlation = Strength and direction of association. Regression = Prediction. Randomization = The gold standard for controlling both known and **unknown** confounders.

Flashcard 39: _____ is used to detect bias publication

Answer: funnel plot

Extra: 

Flashcard 40: 5ce54378cee641398d486f0bc8c03a91-ao-4

Answer: false positive error rate

Extra: