Table 3 Linear regressions examining the association between reasons for individual product use and co-use with monthly use sessions for (a) nicotine vaping use, (b) cannabis vaping, and (c) cannabis smoking (n = 112)

 User experience

0.24

−0.19

0.67

0.28

0.37

−0.00

0.74

0.05

−0.12

−0.47

0.24

0.51

 Product/substance

−0.12

−0.51

0.27

0.53

−0.16

−0.50

0.18

0.35

0.11

−0.21

0.43

0.50

 Utility

0.32*

0.03

0.60

0.03

−0.17

−0.43

0.08

0.18

−0.17

−0.40

0.07

0.16

 Harm reduction

0.21*

0.04

0.37

0.01

−0.06

−0.21

0.09

0.44

0.05

−0.09

0.19

0.46

 User experience

−0.05

−0.45

0.35

0.81

0.14

−0.16

0.45

0.35

−0.05

−0.35

0.24

0.73

 Product/substance

0.04

−0.41

0.50

0.85

0.20

−0.15

0.55

0.25

−0.12

−0.45

0.22

0.50

 Utility

0.19

−0.10

0.47

0.20

−0.02

−0.24

0.20

0.88

0.12

−0.10

0.33

0.28

 Harm reduction

−0.16

−0.38

0.06

0.14

0.08

−0.09

0.25

0.35

0.11

−0.05

0.27

0.18

 User experience

−0.05

−0.45

0.35

0.81

0.26

−0.07

0.58

0.12

−0.17

−0.45

0.11

0.24

 Product/substance

0.38

−0.05

0.81

0.08

−0.25

−0.61

0.10

0.16

0.33*

0.03

0.64

0.03

 Utility

−0.41*

−0.72

−0.10

0.01

−0.04

−0.31

0.23

0.75

0.19

−0.04

0.42

0.10

 Harm reduction

−0.04

−0.26

0.17

0.68

0.08

−0.10

0.26

0.37

−0.02

−0.18

0.13

0.78

 Instrumentality

0.26**

0.08

0.44

0.01

0.04

−0.11

0.20

0.58

−0.06

−0.20

0.08

0.37

 Displacement

−0.20

−0.40

0.01

0.06

0.07

−0.10

0.24

0.43

0.14

−0.01

0.29

0.07

 Social context

0.02

−0.14

0.17

0.83

0.01

−0.12

0.14

0.90

0.05

−0.06

0.17

0.35

 Experimentation

−0.01

−0.19

0.18

0.95

−0.06

−0.21

0.09

0.45

0.06

−0.07

0.20

0.35