Youth vaping and smoking and parental vaping: a panel survey

BMC Public Health

Table 2 Calculation and interpretation of propensity weights

Estimand	How predicted probabilities of exposure are used to calculate weights^a:		Re-weighting of confounding characteristics in exposure groups:		Estimated effect for youth vaping applies to …	Estimated effect for Parental Vaping applies to …
Estimand	Numerator	Denominator	Unexposed	Exposed
Average Treatment Effect (ATE)	P	P^	Resemble sample characteristics	Resemble sample characteristics	All youth	All youth
Average Treatment Effect among the Treated (ATT)	1 if exposed, 1-P^ if unexposed	1 if exposed, P^ if unexposed	Resemble Exposed group	Unchanged	Youth who do vape	Youth whose parents did vape

P=Overall, unadjusted probability of individual’s observed exposure level
P^=Predicted probability of individual’s observed exposure level conditional on confounders
^aWhen investigating effects of parental vaping within strata of parental smoking, both P and P^ were additionally conditional on parental smoking

ISSN: 1471-2458