how many percent of data are included in the range mean±1,2,3SD1SD 68%
2SD 95%
3SD 99.7% statisticsUWorld May 30, 2020, 2:43 AM HirotoShishido
three common statistical testst-test→checks the difference between means of 2 groups
ANOVA(ANalysis Of VAriance)→ means of 3 or more groups
chi-square→ 2 or more percentages or proportions of CHItegorial outcomes
(comparing the percentage of members of 3 different ethnic groups who have essential hypertension)
case series study
crossover studydescriptive study that tracks patients with a known condition to document the natural history. cannot signify statistical significance
Compares the effect of a series of ≥2 treatments on a participant.
Order is randomized. Washout period occurs between each treatment. public healthstatisticsUWorld May 3, 2020, 4:50 AM HirotoShishido
intention-to-treat (ITT) analysisITT analysis compares treatment groups in a randomized trial by including all subjects as initially allocated after randomization regardless of what happens during the study period.
The rationale is that if subjects have such a poor treatment response (or are so inconvenienced by treatment administration or side effects) as to not follow protocol specifications or drop out of the study, then their outcomes should be attributed to that intervention
type Ⅰ, Ⅱ errortype Ⅰ: false-positive error(α)
(ur Accused an innocent man)
α= significance level= probability of making a type Ⅰ error
confidence level=1-α(≒specificity)
(eg. decreased α→ increased confidence level→ ☆any statistically significant findings can reported with a greater levels of confidence)
type Ⅱ: false-negavite error(β)
(Blindly let the guilty man go free)
☆power=1-β(≒sensitivity) statisticsUWorld Feb 13, 2020, 9:00 PM HirotoShishido
