SMR: Standardized Mortality Ratio (SMR)

Description

Computes the SMR, its confidence interval and its associated p-value

Usage

SMR(
  futime,
  status,
  age,
  sex,
  entry_date,
  ratetable = survexp.fr::survexp.fr,
  alpha = 0.05
)

Value

A list containing the observed number of deaths, the expected number of deaths, the "classic" SMR (with its confidence interval and its p-value) and the SMR calculated by a Poisson model (with its confidence interval and its p-value)

Arguments

futime: follow-up time of the subjects in days
status: 0 if censored or 1 if dead at futime
age: age in days
sex: "male" or "female"
entry_date: entry date in the study
ratetable: a table of event rates, such as survexp.fr or survexp.us
alpha: determines the confidence level (1-alpha) of the confidence interval

Author

Jean-Philippe Jais and Hugo Varet

Details

The SMR is estimated using two different methods.

The classic method is: $$SMR = O/E$$ where $O$ is the observed number of deaths and $E$ is the expected number based on the patients' characteristics (sex, age and entry date in the study).

The SMR is also estimated performing a Poisson model where $O$ is the dependant variable and $E$ is an offset.

References

N. Breslow and N. Day, Statistical methods in cancer research, Volume II - The design and analysis of cohort studies, World Health Organization, 1987

Examples

Run this code

attach(data.example)
SMR(futime, status, age, sex, entry_date)

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