Smoking pack-years

Source: R/smoking.R

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.

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)

Value

value for smoking pack-years in the pack_years_der variable

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.

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"
  )
)

#> No variable_details detected.
#>               Loading cchsflow variable_details
#> Using the passed data variable name as database_name
#> NOTE for SMKG09C: Don't know (7) and refusal (8) not included in CCHS 2015-2016 and CCHS 2017-2018
#> NOTE for SMKG207_cont: Missing 2001 Data
#> NOTE for SMKG207_cont: Missing 2001 Data
#> NOTE for SMKG207_cont: Missing 2001 Data
#> NOTE for SMKG207_cont: Missing 2001 Data
#> NOTE for SMKG207_cont: Missing 2001 Data

head(pack_years2009_2010)

#>   DHHGAGE_cont SMK_01A SMK_05B SMK_05C SMK_09A_B SMK_204 SMK_208 SMKDSTY_A
#> 1           13       2      NA      NA     NA(a)      NA      NA         6
#> 2           27       2      NA      NA     NA(a)      NA      NA         6
#> 3           62       2      NA      NA     NA(a)      NA      NA         5
#> 4           52       1      NA      NA         4      NA      20         4
#> 5           67       1      NA      NA         4      NA      35         4
#> 6           62       1      NA      NA         4      NA      25         4
#>   SMKG01C_cont SMKG09C SMKG203_cont SMKG207_cont time_quit_smoking
#> 1           NA   NA(a)           NA           NA                NA
#> 2           NA   NA(a)           NA           NA                NA
#> 3           16   NA(a)           NA           NA                NA
#> 4           16       2           NA         18.5                 8
#> 5           16       3           NA         16.0                12
#> 6            8       3           NA          8.0                12
#>   pack_years_der
#> 1          0.000
#> 2          0.000
#> 3          0.007
#> 4         25.500
#> 5         68.250
#> 6         52.500

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"
  )
)

#> No variable_details detected.
#>               Loading cchsflow variable_details
#> Using the passed data variable name as database_name
#> NOTE for SMKG09C: Don't know (7) and refusal (8) not included in CCHS 2015-2016 and CCHS 2017-2018
#> NOTE for SMKG207_cont: Missing 2001 Data
#> NOTE for SMKG207_cont: Missing 2001 Data
#> NOTE for SMKG207_cont: Missing 2001 Data
#> NOTE for SMKG207_cont: Missing 2001 Data
#> NOTE for SMKG207_cont: Missing 2001 Data

tail(pack_years2011_2012)

#>     DHHGAGE_cont SMK_01A SMK_05B SMK_05C SMK_09A_B SMK_204 SMK_208 SMKDSTY_A
#> 195         72.0       1      NA      NA         4      NA       3         4
#> 196         22.0       2      NA      NA     NA(a)      NA      NA         5
#> 197         18.5       2      NA      NA     NA(a)      NA      NA         6
#> 198         42.0       1      NA      NA         4      NA      10         4
#> 199         62.0       1      NA      NA     NA(a)      20      NA         1
#> 200         52.0       1      NA      NA     NA(a)      13      NA         1
#>     SMKG01C_cont SMKG09C SMKG203_cont SMKG207_cont time_quit_smoking
#> 195           16       3           NA           16                12
#> 196           13   NA(a)           NA           NA                NA
#> 197           NA   NA(a)           NA           NA                NA
#> 198           16       2           NA           16                 8
#> 199           16   NA(a)           NA           NA                NA
#> 200           13   NA(a)           16           NA                NA
#>     pack_years_der
#> 195          6.600
#> 196          0.007
#> 197          0.000
#> 198          9.000
#> 199             NA
#> 200         23.400

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

head(combined_pack_years)

#>   DHHGAGE_cont SMK_01A SMK_05B SMK_05C SMK_09A_B SMK_204 SMK_208 SMKDSTY_A
#> 1           13       2      NA      NA     NA(a)      NA      NA         6
#> 2           27       2      NA      NA     NA(a)      NA      NA         6
#> 3           62       2      NA      NA     NA(a)      NA      NA         5
#> 4           52       1      NA      NA         4      NA      20         4
#> 5           67       1      NA      NA         4      NA      35         4
#> 6           62       1      NA      NA         4      NA      25         4
#>   SMKG01C_cont SMKG09C SMKG203_cont SMKG207_cont time_quit_smoking
#> 1           NA   NA(a)           NA           NA                NA
#> 2           NA   NA(a)           NA           NA                NA
#> 3           16   NA(a)           NA           NA                NA
#> 4           16       2           NA         18.5                 8
#> 5           16       3           NA         16.0                12
#> 6            8       3           NA          8.0                12
#>   pack_years_der
#> 1          0.000
#> 2          0.000
#> 3          0.007
#> 4         25.500
#> 5         68.250
#> 6         52.500
tail(combined_pack_years)

#>     DHHGAGE_cont SMK_01A SMK_05B SMK_05C SMK_09A_B SMK_204 SMK_208 SMKDSTY_A
#> 395         72.0       1      NA      NA         4      NA       3         4
#> 396         22.0       2      NA      NA     NA(a)      NA      NA         5
#> 397         18.5       2      NA      NA     NA(a)      NA      NA         6
#> 398         42.0       1      NA      NA         4      NA      10         4
#> 399         62.0       1      NA      NA     NA(a)      20      NA         1
#> 400         52.0       1      NA      NA     NA(a)      13      NA         1
#>     SMKG01C_cont SMKG09C SMKG203_cont SMKG207_cont time_quit_smoking
#> 395           16       3           NA           16                12
#> 396           13   NA(a)           NA           NA                NA
#> 397           NA   NA(a)           NA           NA                NA
#> 398           16       2           NA           16                 8
#> 399           16   NA(a)           NA           NA                NA
#> 400           13   NA(a)           16           NA                NA
#>     pack_years_der
#> 395          6.600
#> 396          0.007
#> 397          0.000
#> 398          9.000
#> 399             NA
#> 400         23.400