Table 1

Characteristics of adults 18–39 years at wave 2 of the PATH Study*, by lifetime asthma status (percentages and means are weighted to reflect US population)

(N=10 267)
Doctor ever said you have asthma?P value§
Asthma medication in P12M?†
N‡% or mean%%%
Past 30-day tobacco use
 Combustible versus non-combustible tobacco use0.41
  Never used tobacco201030.530.928.626.0
  Formerly used tobacco323134.033.735.239.3
  Non-combustible use only3923.
  Any combustible use463432.432.333.429.9
 Specific tobacco products used
Other smoke-related exposures
 Cigarette pack-years (mean)10 2672.
 Past-week hours of SHS exposure (mean)10 2675.
 Past-month marijuana use**222515.214.719.117.2<0.01
Relevant medical history
 Body mass index<0.01
  Class 1 obese152114.614.514.915.0
  Class 2+ obese121212.011.414.821.5
 Asthma Control Test (mean score)142023.1N/A23.720.6<0.01
  No high school degree11588.
  High school grad248421.621.720.619.9
  Some college395036.235.838.939.6
  ≥College graduate210229.429.429.429.5
 Live in an urban area‡‡849984.083.884.091.30.07
  • Online supplemental table 8 reports SEs for all the weighted estimates presented in this table and unweighted Ns for all the variables in the model.

  • *N=10 267 wave 2 adult (age 18–39) respondents without COPD or other non-asthma respiratory diseases at waves 2–4, with wave 4 PATH Study longitudinal (all waves) weights, and complete data on all analytical variables of adult tobacco users. A total of 1408 participants were excluded for missing data on one or more variables in the analysis. Young adults aged 18–24 years, and black participants (or African-Americans) were oversampled relative to population proportions. The weighting procedures adjusted for oversampling and non-response.

  • †Any P12M asthma meds based on an answer of ‘quick-relief inhaler’ or ‘controller or long-acting inhaler including steroid inhaler’ to the question ‘In the past 12 months, which of the following medications did you regularly take for COPD or asthma?’.

  • ‡Unweighted.

  • §Χ2 test was used for categorical variables and ANOVA was used for continuous variables. Bold p values are statistically significant at p<0.05.

  • ¶Estimate should be interpreted with caution because it has low statistical precision. It is based on a denominator sample size of less than 50, or the coefficient of variation of the estimate or its complement is larger than 30%.

  • **Marijuana use variable does not distinguish between combustible and non-combustible use.

  • ††Non-Hispanic.

  • ‡‡Derived at wave 1 of the PATH Study.

  • ANOVA, analysis of variance; COPD, chronic obstructive pulmonary disease; GED, General Education Development (high school equivalency certificate); PATH, Population Assessment of Tobacco and Health; P12M, past 12-month; SHS, secondhand smoke.