ir_calc | R Documentation |
7 different methods that I found online for calculating the confidence interval for a crude incidence rate. Note that these are all two sided. Most of these come from https://www.openepi.com and their documentation and formulas.
Mid-P exact test seems to be the preferred method
"Mid-P exact test" using Miettinen's (1974d) modification, as described in Epidemiologic Analysis with a Programmable Calculator, 1979.
"Fisher's exact test" based on the formula (Armitage,1971; Snedecor & Cochran,1965) as described in Epidemiologic Analysis with a Programmable Calculator, 1979.
"Exact Poisson is the same as the Fisher's exact but calculated differently.
"Normal approximation" to the Poisson distribution as described by Rosner, Fundamentals of Biostatistics (5th Ed).
"Byar approx. Poisson" as described in Rothman and Boice, Epidemiologic Analysis with a Programmable Calculator, 1979.
"Rothman/Greenland" as described in Rothman and Greenland, Modern Epidemiology (2nd Ed).
"CCRB" comes from the follwing website and they do not offer documentation for their methods: http://www2.ccrb.cuhk.edu.hk/stat/confidence%20interval/CI%20for%20single%20rate.htm
ir_calc(a, N, pt_units = 100, alpha = 0.05, interval = c(0, 1e+07))
a |
Number of clinical events |
N |
Person-time at risk |
pt_units |
Factor to multiply rate by to get Person-time; default is 100. |
alpha |
Significance level for two-sided confidence interval |
interval |
a vector containing the end-points of the interval to be
searched for the root. The function |
A tbl_df
http://epid.blogspot.com/2012/08/how-to-calculate-confidence-interval-of.html https://www.openepi.com/PDFDocs/PersonTime1Doc.pdf https://seer.cancer.gov/seerstat/WebHelp/Rate_Algorithms.htm
# options(pillar.sigfig = 3)
ir_calc(a = 18,
N = 352 + 10.5,
alpha = 0.05)
#### From https://www.openepi.com --------------------------------
# Person-Time Rate and 95% Confidence Intervals
# Per 100 Person-Time Units
# Number of cases: 18
# Person-Time: 362.5
#
# Lower CL Rate Upper CL
# Mid-P exact test 3.035 4.966 7.696
# Fisher's exact test 2.943 7.848
# Normal approximation 2.672 7.259
# Byar approx. Poisson 2.941 7.848
# Rothman/Greenland 3.129 7.881
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