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Smoking pack-years

Source: R/smoking.R
pack_years_fun.Rd

This function calculates an individual's smoking pack-years based on various CHMS smoking variables. Pack years is a measure used by researchers to quantify lifetime exposure to cigarette use.

Usage

pack_years_fun(
  SMKDSTY,
  CLC_AGE,
  SMK_54,
  SMK_52,
  SMK_31,
  SMK_41,
  SMK_53,
  SMK_42,
  SMK_21,
  SMK_11
)

Arguments

SMKDSTY

An integer representing the smoking status of the respondent:

  • 1: Daily smoker

  • 2: Occasional smoker (former daily)

  • 3: Occasional smoker (never daily)

  • 4: Former daily smoker (non-smoker now)

  • 5: Former occasional smoker (non-smoker now) who smoked at least 100 cigarettes in their lifetime

  • 6: Non-smoker (never smoked more than 100 cigarettes)

CLC_AGE

A numeric value representing the respondent's age.

SMK_54

A numeric value representing the respondent's age when they stopped smoking daily.

SMK_52

A numeric value representing the respondent's age when they first started smoking daily.

SMK_31

An numeric representing the number of cigarettes smoked per day for daily smokers.

SMK_41

A numeric value representing the number of cigarettes smoked per day for occasional smokers.

SMK_53

A numeric value representing the number of cigarettes smoked per day for former daily smokers.

SMK_42

A numeric value representing the number of days in past month the respondent smoked at least 1 cigarette (for occasional smokers).

SMK_21

A numeric value representing the respondent's age when they first started smoking occasionally.

SMK_11

An integer representing whether the respondent has smoked at least 100 cigarettes in their lifetime:

  • 1: Yes

  • 2: No

Value

A numeric value representing the pack years for the respondent's smoking history.

  • If CLC_AGE is missing or negative, returns tagged_na("b").

  • For different smoking statuses (SMKDSTY), the function calculates pack years as follows:

    • Daily smoker (1): pmax(((CLC_AGE - SMK_52) * (SMK_31 / 20)), 0.0137)

    • Occasional smoker (former daily) (2): pmax(((CLC_AGE - SMK_52 - (CLC_AGE - SMK_54)) * (SMK_53 / 20)), 0.0137) + ((pmax((SMK_41 * SMK_42 / 30), 1) / 20) * (CLC_AGE - SMK_54))

    • Occasional smoker (never daily) (3): (pmax((SMK_41 * SMK_42 / 30), 1) / 20) * (CLC_AGE - SMK_21)

    • Former daily smoker (4): pmax(((CLC_AGE - SMK_52 - (CLC_AGE - SMK_54)) * (SMK_53 / 20)), 0.0137)

    • Former occasional smoker (5):

      • If SMK_11 == 1 (≥100 cigarettes): 0.0137

      • If SMK_11 == 2 (<100 cigarettes): 0.007

    • Non-smoker (6): 0

    • If SMKDSTY is NA(a), returns tagged_na("a").

    • For all other unexpected inputs, returns tagged_na("b").

See also

https://big-life-lab.github.io/cchsflow/reference/pack_years_fun.html

Examples


# Example 1: Age = 40, daily smoker, started smoking at 20, and smokes 30 cigs/day (1.5 packs/day).
pack_years_fun(SMKDSTY = 1, CLC_AGE = 40, SMK_52 = 20, SMK_31 = 30)
#> [1] 30
# Output: 30 (pack years)

# Example 2: A former occasional smoker who smoked at least 100 cigarettes in their lifetime.
pack_years_fun(
  SMKDSTY = 5, CLC_AGE = 50, SMK_54 = 40, SMK_52 = 18, SMK_31 = NA,
  SMK_41 = 15, SMK_53 = NA, SMK_42 = 3, SMK_21 = 25, SMK_11 = 1
)
#> [1] 0.0137
# Output: 0.0137 (pack years)