es_from_chisq function

Convert a chi-square value to several effect size measures

es_from_chisq(
  chisq,
  n_sample,
  n_cases,
  n_exp,
  yates_chisq = FALSE,
  reverse_chisq
)

Arguments

• chisq: value of the chi-squared
• n_sample: total number of participants in the sample
• n_cases: total number of cases/events
• n_exp: total number of participants in the exposed group
• yates_chisq: a logical value indicating whether the Chi square has been performed using Yate's correction for continuity.
• reverse_chisq: a logical value indicating whether the direction of generated effect sizes should be flipped.

Returns

This function estimates and converts between several effect size measures.

natural effect size measure	OR + RR + NNT
converted effect size measure	D + G + R + Z
required input data	See 'Section 8. Phi or chi-square'
	https://metaconvert.org/input.html

Details

This function converts a chi-square value (with one degree of freedom) into a phi coefficient (Lipsey et al. 2001):

$$phi = \sqrt{\frac{chisq^2}{n\_sample}}$$

.

Note that if yates_chisq = "TRUE", a small correction is added.

Then, the phi coefficient is converted to other effect size measures (see es_from_phi).

Examples

es_from_chisq(chisq = 4.21, n_sample = 78, n_cases = 51, n_exp = 50)

References

Lipsey, M. W., & Wilson, D. B. (2001). Practical meta-analysis. Sage Publications, Inc.