propdiff_ac function

Calculates the difference between proportions and standard error according to method Agresti-Caffo

propdiff_ac Calculates the difference between proportions and standard error according to method Agresti-Caffo.

propdiff_ac(y, x, formula, data)

Arguments

• y: 0-1 binary response variable.
• x: 0-1 binary independent variable.
• formula: A formula object to specify the model as normally used by glm.
• data: An objects of class milist, created by df2milist, list2milist or mids2milist.

Returns

The difference between proportions, the standard error according to Agresti-Caffo and complete data degrees of freedom (dfcom) as n-1.

Details

As output the differences between proportions according to Agresti-Caffo and Wald are provided. The Agresti-Caffo difference is used in the function pool_propdiff_ac to derive the Agresti-Caffo confidence intervals. For the pooled difference between proportions the difference between proportions according to Wald are used.

Examples

imp_dat <- df2milist(lbpmilr, impvar="Impnr")
ra <- with(imp_dat, expr=propdiff_ac(Chronic ~ Radiation))

# same as
ra <- with(imp_dat, expr=propdiff_ac(y=Chronic, x=Radiation))

References

Agresti, A. and Caffo, B. Simple and Effective Confidence Intervals for Proportions and Differences of Proportions Result from Adding Two Successes and Two Failures. The American Statistician. 2000;54:280-288.

Fagerland MW, Lydersen S, Laake P. Recommended confidence intervals for two independent binomial proportions. Stat Methods Med Res. 2015 Apr;24(2):224-54.

See Also

with.milist, pool_propdiff_ac

Author(s)

Martijn Heymans, 2021