Table 2.

E-cigarette post-trend estimated coefficients, standard errors, t values, p values, and confidence intervals

	Coefficient	Standard error	t value	p value	95% confidence interval
Baseline
GBA	4.140104	3.051848	1.36	0.177	− 1.898052	10.17826
USA	95.65063	3.482517	27.47	0.000*	88.76039	102.5409
EVALI
GBA	− 3.6925	0.6550	− 5.6369	0.0000*	− 4.9885	− 2.3964
USA	− 3.0662	0.8282	− 3.7021	0.0003*	− 4.7049	− 1.4275
Difference	− 0.6263	0.6432	− 0.9737	0.3320	− 1.8988	0.6463
MA ban
GBA	− 2.2510	0.7901	− 2.8490	0.0051*	− 3.8142	− 0.6878
USA	− 0.4350	0.7573	− 0.5745	0.5667	− 1.9334	1.0633
Difference	− 1.8159	0.6195	− 2.9312	0.0040*	− 3.0417	− 0.5902
After ban ended
GBA	0.5744	0.6246	0.9196	0.3595	− 0.6614	1.8102
USA	− 0.4180	0.5692	− 0.7343	0.4641	− 1.5442	0.7082
Difference	0.9924	0.2911	3.4086	0.0009*	0.4164	1.5684
COVID-19
GBA	− 0.5267	0.5933	− 0.8877	0.3763	− 1.7005	0.6471
USA	− 0.7272	0.6887	− 1.0559	0.2930	− 2.0899	0.6355
Difference	0.2006	0.6068	0.3305	0.7415	− 0.9999	1.4010
MA tax
GBA	− 0.9344	0.4942	− 1.8907	0.0609	− 1.9122	0.0434
USA	− 2.1260	0.5320	− 3.9965	0.0001*	− 3.1785	− 1.0735
Difference	1.1916	0.4405	2.7051	0.0078*	0.3201	2.0631

The post-trend regression coefficients for e-cigarette purchasing in the Greater Boston area and the USA at baseline and after the four intervention points, the difference between the coefficients of the two groups, along with the standard error, t value, p statistic, and 95% confidence interval for each value. Asterisks (*) indicate significance at p < 0.05