Table 3.

Association of the diet quality index and demographic and socio-economic factors with the cost of the diet of grade 5 students in Alberta

Univariable model			Multivariable model
	β coefficient	95% CI	β coefficient	95% CI
DQI	0.07**	0.05–0.08	0.07**	0.05–0.09
Gender
Girls	Ref		Ref
Boys	− 0.30*	− 0.53 to − 0.07	− 0.15	− 0.44–0.14
Parental income
≤ $50,000	Ref		Ref
$50,001–$75,000	− 0.03	− 0.54–0.48	− 0.02	− 0.56–0.51
$75,001–$100,000	0.55*	0.08–1.03	0.52*	0.00–1.03
≥ $100,001	0.73**	0.34–1.12	0.65*	0.19–1.10
Food security
Worry that food would run out before getting money to buy more
Yes	Ref		Ref
No	0.56*	0.17–0.94	0.64	− 0.05–1.33
The food bought did not last and no money to buy more
Yes	Ref		Ref
No	0.28	− 0.21–0.77	− 0.57	− 1.40–0.26
Parental education
High school or less	Ref		Ref
Community/technical college	0.29	− 0.00–0.60	0.07	− 0.32–0.46
University degree	0.41*	0.11–0.72	0.01	− 0.40–0.41
Urbanization status
Metropolitan	Ref		Ref
Rural or town	0.22	− 0.03–0.49	0.1	− 0.25–0.44
City	0.58**	0.24–0.91	0.25	− 0.17–0.68
Body weight status
Normal	Ref		Ref
Overweight	0.29	− 0.20–0.77	0.6	− 0.15–1.22
Obese	− 0.13	− 0.69–0.43	− 0.6	− 1.28–0.1

DQI, Diet Quality Index; all costs are in 2016 Canadian dollars. The multivariable model was adjusted for all variables listed in the table and for calorie intake

*p < 0.05, **p < 0.001