pack_years_fun {cchsflow}

Smoking pack-years

Description

This function creates a derived variable (pack_years_der) that measures an individual's smoking pack-years based on various CCHS smoking variables. This is a popular variable used by researchers to quantify lifetime exposure to cigarette use.

Usage

pack_years_fun(
  SMKDSTY_A,
  DHHGAGE_cont,
  time_quit_smoking,
  SMKG203_cont,
  SMKG207_cont,
  SMK_204,
  SMK_05B,
  SMK_208,
  SMK_05C,
  SMKG01C_cont,
  SMK_01A
)

Arguments

SMKDSTY_A

variable used in CCHS cycles 2001-2014 that classifies an individual's smoking status.

DHHGAGE_cont

continuous age variable.

time_quit_smoking

derived variable that calculates the approximate time a former smoker has quit smoking. See time_quit_smoking_fun for documentation on how variable was derived

SMKG203_cont

age started smoking daily. Variable asked to daily smokers.

SMKG207_cont

age started smoking daily. Variable asked to former daily smokers.

SMK_204

number of cigarettes smoked per day. Variable asked to daily smokers.

SMK_05B

number of cigarettes smoked per day. Variable asked to occasional smokers

SMK_208

number of cigarettes smoked per day. Variable asked to former daily smokers

SMK_05C

number of days smoked at least one cigarette

SMKG01C_cont

age smoked first cigarette

SMK_01A

smoked 100 cigarettes in lifetime (y/n)

Details

pack-years is calculated by multiplying the number of cigarette packs per day (20 cigarettes per pack) by the number of years. Example 1: a respondent who is a current smoker who smokes 1 package of cigarettes for the last 10 years has smoked 10 pack-years. Pack-years is also calculated for former smokers. Example 2: a respondent who started smoking at age 20 years and smoked half a pack of cigarettes until age 40 years smoked for 10 pack-years.

Value

value for smoking pack-years in the pack_years_der variable

Examples

# Using pack_years_fun() to create pack-years values across CCHS cycles
# pack_years_fun() is specified in variable_details.csv along with the CCHS
# variables and cycles included.

# To transform pack_years_der across cycles, use rec_with_table() for each
# CCHS cycle and specify pack_years_der, along with each smoking variable.
# Since time_quit_smoking_der is also a derived 
# variable, you will have to specify the variables that are derived from it.
# Then by using merge_rec_data(), you can combine pack_years_der across
# cycles

library(cchsflow)

pack_years2009_2010 <- rec_with_table(
  cchs2009_2010_p, c(
    "SMKDSTY_A", "DHHGAGE_cont", "SMK_09A_B", "SMKG09C", "time_quit_smoking",
    "SMKG203_cont", "SMKG207_cont", "SMK_204", "SMK_05B", "SMK_208",
    "SMK_05C", "SMK_01A", "SMKG01C_cont", "pack_years_der"
  )
)

head(pack_years2009_2010)

pack_years2011_2012 <- rec_with_table(
  cchs2011_2012_p,c(
    "SMKDSTY_A", "DHHGAGE_cont", "SMK_09A_B", "SMKG09C", "time_quit_smoking",
    "SMKG203_cont", "SMKG207_cont", "SMK_204", "SMK_05B", "SMK_208",
    "SMK_05C", "SMK_01A", "SMKG01C_cont", "pack_years_der"
  )
)

tail(pack_years2011_2012)

combined_pack_years <- suppressWarnings(merge_rec_data(pack_years2009_2010,
 pack_years2011_2012))

head(combined_pack_years)
tail(combined_pack_years)