correlated_rates: Ratios of correlated age-adjusted rates.
In mlaviolet/tidyepi: Functions for Epidemiology Analysis

correlated_rates

R Documentation

Ratios of correlated age-adjusted rates.

Description

Function to compute ratios of correlated age-adjusted rates with a confidence interval that accounts for the correlation. This is useful for comparing the rate of a subregion (e.g. a county) with its parent (e.g. its state).

Usage

correlated_rates(
  df,
  region,
  agegroup,
  events,
  person_yrs,
  std_pop,
  parent = "Parent Region",
  base = 1e+05,
  level = 95,
  dec_rate = 1,
  dec_ratio = 2
)

Arguments

`df`	A data frame with columns for region, age group, event counts, and person-years totals as described in the next four arguments
`region`	Subregion for which to calculate adjusted rates.
`agegroup`	Age group or other stratifying variable.
`events`	Number of events.
`person_yrs`	Number of person-years at risk.
`std_pop`	Vector of standard population distribution. Can be totals, proportions, or percentages.
`parent`	Name of parent region.
`base`	Multiplier; e.g. per 100,000 population.
`level`	Confidence level expressed as percentage.
`dec_rate`	Decimal places to round adjusted rates.
`dec_ratio`	Decimal places to round rate ratios.

Value

A data table with the following fields:

events: Number of events.
person_yrs: Total person-years at risk.
adj_rate: Age-adjusted rate.
adj_rate_stderr: Standard error of age-adjusted rate.
adj_lci: Lower confidence limit of age-adjusted rate per Tiwari (2006)
adj_uci: Upper confidence limit for age-adusted rate per Tiwari (2006)

References

Tiwari RC et al. (2006) Efficient interval estimation for age-adjusted cancer rates. Statistical Methods in Medical Research 15:547-569. https://www.ncbi.nlm.nih.gov/pubmed/17260923

Tiwari RC et al. (2010) Interval estimation for ratios of correlated age-adjusted rates. Journal of Data Science 8:471-482. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3279758/

Examples

# Age-adjusted COPD mortality rates by state with ratio to US rate and confidence intervals, 2016
copd_rates <- correlated_rates(copd, State, agegroup, Deaths, Population, 
              std_pop = c(23961, 18136, 12315, 4259), parent = "United States")

mlaviolet/tidyepi documentation built on Feb. 19, 2025, 5:39 p.m.