Convenience Functions to Compute Probabilities

Source: R/transform.R

These convienience functions make it easier to compute transition probabilities from indidence rates, OR, RR, or probabilities estimated on a different timeframe.

rescale_prob(p, to = 1, from = 1)

prob_to_prob(...)

rate_to_prob(r, to = 1, per = 1)

or_to_prob(or, p)

rr_to_prob(rr, p)

Arguments

p

Probability.
to

Compute probability for that timeframe.
from

Timeframe of the original probability.
...

For deprecated functions.
r

Rate.
per

Number of person-time corresponding to the rate.
or

Odds ratio.
rr

Relative risk.

Value

A probability.

Examples

# convert 5-year probability 
# to 1-year probability
rescale_prob(p = .65, from = 5)

#> [1] 0.1893869

# convert 1-year probability 
# to 1-month probability
rescale_prob(p = .5, to = 1/12)

#> [1] 0.05612569

# convert rate per 1000 PY
# to 5-year probability
rate_to_prob(r = 162, per = 1000, to = 5)

#> [1] 0.5551419

# convert OR to probability
or_to_prob(or = 1.9, p = .51)

#> [1] 0.6272371

# convert RR to probability
rr_to_prob(rr = 1.9, p = .51)

#> [1] 0.969