This function calculates odds ratio(s) for specific increment steps of GLMs.

or_glm(data, model, incr, ci = 0.95)

Arguments

data

The data used for model fitting.

model

A fitted GLM(M).

incr

Increment values of each predictor given in a named list.

ci

Which confidence interval to calculate. Must be between 0 and 1. Default to 0.95

Value

A data frame with five columns:

predictor

Predictor name(s)

oddsratio

Calculated odds ratio(s)

ci_low

Lower confident interval of odds ratio

ci_high

Higher confident interval of odds ratio

increment

Increment of the predictor(s)

Details

ci_low and ci_high are only calculated for GLM models because MASS::glmmPQL() does not return confident intervals due to its penalizing behavior.

Currently supported functions: stats::glm,MASS::glmmPQL

See also

Examples

## Example with glm() library(oddsratio) # load data (source: http://www.ats.ucla.edu/stat/r/dae/logit.htm) and # fit model fit_glm <- glm(admit ~ gre + gpa + rank, data = data_glm, family = "binomial" ) # fit model # Calculate OR for specific increment step of continuous variable or_glm(data = data_glm, model = fit_glm, incr = list(gre = 380, gpa = 5))
#> predictor oddsratio ci_low (2.5) ci_high (97.5) increment #> 1 gre 2.364 1.054 5.396 380 #> 2 gpa 55.712 2.229 1511.282 5 #> 3 rank2 0.509 0.272 0.945 Indicator variable #> 4 rank3 0.262 0.132 0.512 Indicator variable #> 5 rank4 0.212 0.091 0.471 Indicator variable
# Calculate OR and change the confidence interval level or_glm( data = data_glm, model = fit_glm, incr = list(gre = 380, gpa = 5), ci = .70 )
#> predictor oddsratio ci_low (15) ci_high (85) increment #> 1 gre 2.364 1.540 3.647 380 #> 2 gpa 55.712 10.084 314.933 5 #> 3 rank2 0.509 0.366 0.706 Indicator variable #> 4 rank3 0.262 0.183 0.374 Indicator variable #> 5 rank4 0.212 0.136 0.325 Indicator variable
## Example with MASS:glmmPQL() # load data library(MASS) data(bacteria) fit_glmmPQL <- glmmPQL(y ~ trt + week, random = ~ 1 | ID, family = binomial, data = bacteria, verbose = FALSE ) # Apply function or_glm(data = bacteria, model = fit_glmmPQL, incr = list(week = 5))
#> Warning: No confident interval calculation possible for 'glmmPQL' models.
#> predictor oddsratio ci_low ci_high increment #> 1 trtdrug 0.296 NA NA Indicator variable #> 2 trtdrug+ 0.454 NA NA Indicator variable #> 3 week 0.485 NA NA 5