Table 3.

Quality assessment of non-randomized studies of interventions examining the effects of e-cigarettes on lung function, as defined by the ROBINS-I tool.

	Bias due to confounding	Bias in the selection of participants for the study	Bias in the classification of interventions	Bias due to deviations from the intended intervention	Bias due to missing data	Bias in the measurement of outcomes	Bias in the selection of the reported result	Overall
Palamidas 2013	Moderate	Moderate	Low	Low	No Information	No Information	Moderate	Moderate
Palamidas 2017	Moderate	Low	Low	Low	Low	No Information	Low	Moderate
Polosa 2017	Serious	Low	Low	Low	Moderate	Low	Moderate	Serious
Coppeta 2018	Low	Low	Low	Low	No Information	Moderate	Low	Moderate
Kizhakke Puliyakote 2021	Moderate	Low	Moderate	Low	Low	Moderate	Low	Moderate