Table 2 : Proportions and bounds for 95% confidence intervals, by attempt.


Number of Attempt Proportion of Successes Lower Bound Upper Bound Sample Size

1 0.463 0.422 0.504 592
2 0.438 0.3823 0.495 315
3 0.439 0.363 0.516 171
4 0.330 0.235 0.436 91
5 0.527 0.388 0.664 55
6 0.409 0.207 0.637 22
7 0.364 0.109 0.692 11
8 0.333 0.043 0.777 6
9 1 0.158 1 2

This table lists the actual proportion of successes, along with lower and upper bounds for
a 95% confidence interval, for each attempt to start an IV. Once a patient experienced a
successful IV, they were removed from further analysis. Thus, the sample size for each attempt
is diminished as the number of the attempt increases.

Brinkley et al.Journal of Medical Statistics and Informatics  2014 2:6DOI : 10.7243/2053-7662-2-6