Table 2

Goodness of fit of the model with true IQOS introduction months versus placebo models

Approach	True introduction date model R²	Simultaneous national-level placebo date models – R² distribution
Approach	True introduction date model R²	Months tested	Mean R²	Top 10%	Top 5%	Max
1	0.7504	47	0.6898	0.7416	0.7434	0.7456
2	0.7466	47	0.6898	0.7416	0.7434	0.7456
3	0.7452	47	0.6910	0.7391	0.7424	0.7449
Approach	True introduction date model R²	Exact permutation test: true model and placebo dates – R² distribution
Approach	True introduction date model R²	True model rank	Permutation count	Significance level	Top 10%	Max
1	0.7504	5	330	1.5%	0.7393	0.7594
2	0.7466	4	55	7.3%	0.7432	0.7514
3	0.7452	2	15	13.3%	0.7452	0.7486

For the simultaneous national-level placebo dates, n=47 (48 months in the dataset minus the first month). The larger the R² value the better the model fits. Ordering the models by the Akaike’s information criteria and Schwarz’s Bayesian information criteria yielded the same results.