es_from_chisq_pval function

Convert a p-value of a chi-square to several effect size measures

es_from_chisq_pval(
  chisq_pval,
  n_sample,
  n_cases,
  n_exp,
  yates_chisq = FALSE,
  reverse_chisq_pval
)

Arguments

• chisq_pval: p-value of a chi-square coefficient
• 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_pval: 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 chi-square coefficient (Section 3.12 in Lipsey et al., 2001):

$$chisq = qchisq(chisq\_pval, df = 1, lower.tail = FALSE)$$

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

Then, the chisq coefficient is converted to other effect size measures (see es_from_chisq).

Examples

es_from_chisq_pval(chisq_pval = 0.2, n_sample = 42, n_exp = 25, n_cases = 13)

References

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