oddsratio_to_riskratio function

Convert Between Odds Ratios, Risk Ratios and Other Metrics of Change in Probabilities

oddsratio_to_riskratio(OR, p0, log = FALSE, verbose = TRUE, ...)

oddsratio_to_arr(OR, p0, log = FALSE, verbose = TRUE, ...)

oddsratio_to_nnt(OR, p0, log = FALSE, verbose = TRUE, ...)

logoddsratio_to_riskratio(logOR, p0, log = TRUE, verbose = TRUE, ...)

logoddsratio_to_arr(logOR, p0, log = TRUE, verbose = TRUE, ...)

logoddsratio_to_nnt(logOR, p0, log = TRUE, verbose = TRUE, ...)

riskratio_to_oddsratio(RR, p0, log = FALSE, verbose = TRUE, ...)

riskratio_to_arr(RR, p0, verbose = TRUE, ...)

riskratio_to_logoddsratio(RR, p0, log = TRUE, verbose = TRUE, ...)

riskratio_to_nnt(RR, p0, verbose = TRUE, ...)

arr_to_riskratio(ARR, p0, verbose = TRUE, ...)

arr_to_oddsratio(ARR, p0, log = FALSE, verbose = TRUE, ...)

arr_to_logoddsratio(ARR, p0, log = TRUE, verbose = TRUE, ...)

arr_to_nnt(ARR, ...)

nnt_to_oddsratio(NNT, p0, log = FALSE, verbose = TRUE, ...)

nnt_to_logoddsratio(NNT, p0, log = TRUE, verbose = TRUE, ...)

nnt_to_riskratio(NNT, p0, verbose = TRUE, ...)

nnt_to_arr(NNT, ...)

Arguments

• OR, logOR, RR, ARR, NNT: Odds-ratio of odds(p1)/odds(p0), log-Odds-ratio of log(odds(p1)/odds(p0)), Risk ratio of p1/p0, Absolute Risk Reduction of p1 - p0, or Number-needed-to-treat of 1/(p1 - p0). OR and logOR

  can also be a logistic regression model.

• p0: Baseline risk

• log: If:

  • TRUE:

    • In oddsratio_to_*(), OR input is treated as log(OR).
    • In *_to_oddsratio(), returned value is log(OR).

  • FALSE:

    • In logoddsratio_to_*(), logOR input is treated as OR.
    • In *_to_logoddsratio(), returned value is OR.

• verbose: Toggle warnings and messages on or off.

• ...: Arguments passed to and from other methods.

Returns

Converted index, or if OR/logOR is a logistic regression model, a parameter table with the converted indices.

Examples

p0 <- 0.4
p1 <- 0.7

(OR <- probs_to_odds(p1) / probs_to_odds(p0))
(RR <- p1 / p0)
(ARR <- p1 - p0)
(NNT <- arr_to_nnt(ARR))

riskratio_to_oddsratio(RR, p0 = p0)
oddsratio_to_riskratio(OR, p0 = p0)
riskratio_to_arr(RR, p0 = p0)
arr_to_oddsratio(nnt_to_arr(NNT), p0 = p0)

m <- glm(am ~ factor(cyl),
  data = mtcars,
  family = binomial()
)
oddsratio_to_riskratio(m, verbose = FALSE) # RR is relative to the intercept if p0 not provided

References

Grant, R. L. (2014). Converting an odds ratio to a range of plausible relative risks for better communication of research findings. Bmj, 348, f7450.

See Also

oddsratio(), riskratio(), arr(), and nnt().

Other convert between effect sizes: d_to_r(), diff_to_cles, eta2_to_f2(), odds_to_probs(), w_to_fei()