An experiment that studies effectiveness of stents in treating patients at risk of stroke with some unexpected results. stent30 represents the results 30 days after stroke and stent365 represents the results 365 days after stroke.

stent30

Format

A data frame with 451 observations on the following 2 variables.

group

a factor with levels control and treatment

outcome

a factor with levels no event and stroke

Source

Chimowitz MI, Lynn MJ, Derdeyn CP, et al. 2011. Stenting versus Aggressive Med- ical Therapy for Intracranial Arterial Stenosis. New England Journal of Medicine 365:993- 1003. doi: 10.1056/NEJMoa1105335 . NY Times article reporting on the study: https://www.nytimes.com/2011/09/08/health/research/08stent.html.

Examples


# 30-day results
table(stent30)
#>            outcome
#> group       no event stroke
#>   control        214     13
#>   treatment      191     33

# 365-day results
table(stent365)
#>            outcome
#> group       no event stroke
#>   control        199     28
#>   treatment      179     45