Package 'RSquaredMI'

Title: R-Squared with Multiply Imputed Data
Description: Provides R-squared values and standardized regression coefficients for linear models applied to multiply imputed datasets as obtained by 'mice'. Confidence intervals, zero-order correlations, and alternative adjusted R-squared estimates are also available. The methods are described in Van Ginkel and Karch (2024) <doi:10.1111/bmsp.12344> and in Van Ginkel (2020) <doi:10.1007/s11336-020-09696-4>.
Authors: Julian D. Karch [aut, cph, cre] , Joost van Ginkel [aut, cph]
Maintainer: Julian D. Karch <[email protected]>
License: AGPL (>= 3)
Version: 0.2.0
Built: 2024-12-05 18:35:49 UTC
Source: CRAN

Help Index


Calculate R-squared with Standardized Predictors

Description

This function calculates the R-squared value for a linear model applied to a multiply imputed dataset, along with standardized regression coefficients. Optionally, it can also return the confidence intervals of the standardized regression coefficients and the zero-order correlations.

Usage

RsquareSP(
  object,
  cor = FALSE,
  conf = FALSE,
  conf.level = 0.95,
  alternative_adj_R2 = FALSE
)

Arguments

object

The results of a regression on a multiply imputed dataset of class 'mira' from the 'mice' package.

cor

Logical. If 'TRUE', the function returns the zero-order correlations between the outcome and each predictor.

conf

Logical. If 'TRUE', the function returns the confidence intervals of the standardized regression coefficients.

conf.level

A real number between 0 and 1 specifying the confidence level of the confidence intervals.

alternative_adj_R2

Logical. If 'TRUE', the function returns alternative estimates of adjusted R^2, as described in the references

Details

The function first completes the imputed datasets using 'mice::complete'. It then calculates the linear model on each imputed dataset and averages the standardized coefficients and correlations across imputations. The final R-squared value is computed as the sum of the products of the averaged standardized coefficients and averaged correlations. The confidence intervals of the standardized regression coefficients are calculated under the assumption that the variables are multivarate normally distributed

Value

A list of class 'RsquaredMI' containing the following elements:

r_squared

The R-squared value calculated using standardized predictors.

r

The square root of the R-squared value, or the multiple correlation R.

rtotal

A vector containing both the R-squared and R.

beta

The standardized regression coefficients.

lower

The lowerbound of the condidence intervals of the standardized regression coefficients (if 'conf = TRUE').

upper

The upperbound of the condidence intervals of the standardized regression coefficients (if 'conf = TRUE').

dfe

The error degrees of freedom of the condidence intervals of the standardized regression coefficients (if 'conf = TRUE').

zero

The zero-order correlations between the outcome and each predictor

total

A matrix containing the betas and optionally (if 'cor = TRUE'), the error degrees of freedom, confidence intervals, and zero-order correlations.

References

Van Ginkel, J.R., & Karch, J.D. (2024). A comparison of different measures of the proportion of explained variance in multiply imputed data sets. British Journal of Mathematical and Statistical Psychology. doi:10.1111/bmsp.12344

Karch, J.D. (2024). Improving on Adjusted R-squared. Collabra: Psychology. doi:10.1525/collabra.343

Van Ginkel, J.R. (2020). Standardized regression coefficients and newly proposed estimators for R^2 in multiply imputed data. Psychometrika. doi:10.1007/s11336-020-09696-4

Examples

library(mice)
imp <- mice(nhanes, print = FALSE, seed = 16117)
fit <- with(imp, lm(chl ~ age + hyp + bmi))
RsquareSP(fit)