Table 1.

Linear Regressions of Live Born Neural Tube Defect (NTD) Rates.

Input Parameters	Parameter Analyses				Model Parameters
	Estimate	SE	t Value	Pr(>|t|)	Adjusted R2	F	df	P
NTD rate by cannabis use by era
Era 1
Cannabis use (annual)	0.0509	0.0353	1.442	.1925	0.1189	2.079	1.7	.1925
Era 2
Cannabis use (annual)	0.0507	0.0096	5.293	.0018	0.7942	28.02	1.6	.0018
Era 3
Cannabis use (annual)	0.1365	0.0614	2.225	.0678	0.3607	4.949	1.6	.0678
NTD rate by cannabis use by time and parameter
Rate ~ year * group (2015)
Year	−0.0897	0.0123	−7.312	.0000	0.6986	32.29	2.25	1.2E-07
Group	0.3174	0.1064	2.984	.0063
Rate ~ year * cannabis use (annual)
Year	−0.0826	0.0128	−6.470	.0000	0.6925	28.03	2.22	8.9E-07
Cannabis use (annual)	0.0447	0.0135	3.311	.0032
Rate ~ year * cannabis use (month)
Year	−0.0836	0.0152	−5.506	.0000	0.6369	19.41	2.19	2.6E-05
Cannabis use (month)	0.0449	0.0172	2.611	.0172
Rate ~ year * age initiation
Year: age initiation	−0.0060	0.0011	−5.532	.0000	0.5788	15.43	2.19	.0001
Age initiation	11.8219	2.1569	5.481	.0000
Rate ~ year * cannabis index
Year	−0.0850	0.0140	−6.060	.0000	0.6714	22.46	2.19	9.9E-06
Cannabis index	0.5046	0.1998	2.526	.0206
Rate ~ year * group (2018)
Year	−0.1301	0.0213	−6.108	.0000	0.7122	23.27	3.24	2.8E-07
Group	110.5561	51.4954	2.147	.0421
Year: group	−0.0552	0.0258	−2.141	.0426
Rate ~ year * cannabis use (3 months, 2018)
Cannabis use (3 months)	11.1933	1.5533	7.206	.0000	0.6753	29.08	2.25	3.0E-07
Year: cannabis use (3 months)	−0.0056	0.0008	−7.179	.0000