Table 1.

Characteristics of the study population, i-Share cohort

	Screen time
	Very low (n=1141)		Low (n=1080)		High (n=1275)		Very high (n=1320)
	n	Per cent	n	Per cent	n	Per cent	n	Per cent
Quintiles of global score*
Never	274	24.0	225	20.8	240	18.8	207	15.7
Rarely	190	16.7	194	18.0	221	17.3	200	15.2
Sometimes	221	19.4	238	22.0	248	19.5	258	19.5
Often	293	25.7	258	23.9	333	26.1	381	28.9
Very often	163	14.3	165	15.3	233	18.3	274	20.8
Age (years)
18	400	35.1	384	35.6	381	29.9	313	23.7
19	228	20.0	192	17.8	244	19.1	207	15.7
20	146	12.8	148	13.7	171	13.4	209	15.8
21 or more	367	32.2	356	33.0	479	37.6	591	44.8
Gender
Male	244	21.4	249	23.1	298	23.4	387	29.3
Study level
1st year	582	51.0	553	51.2	565	44.3	479	36.3
2nd year	200	17.5	180	16.7	239	18.7	285	21.6
3rd year	123	10.8	127	11.8	191	15.0	197	14.9
4th year or higher year of postsecondary education	236	20.7	220	20.4	280	22.0	359	27.2
Paid employment while being a student
No	729	63.9	718	66.5	796	62.4	816	61.8
Parents’ marital status
Not divorced	795	69.7	750	69.4	868	68.1	890	67.4
Parental moral support
Absolutely not/a little	136	11.9	110	10.2	117	9.2	138	10.5
Moderately	212	18.6	202	18.7	257	20.2	271	20.5
A lot	462	40.5	445	41.2	501	39.3	504	38.2
Absolutely yes	331	29.0	323	29.9	400	31.4	407	30.8
Self-report of physician-diagnosed depression
No	1003	87.9	953	88.2	1110	87.1	1138	86.2
Extracurricular activities
No	802	70.3	753	69.7	851	66.7	891	67.5
Sport practice
No	546	47.9	531	49.2	628	49.3	674	51.1
Sleep quality
Good	226	19.8	197	18.2	209	16.4	201	15.2
Quite good	402	35.2	404	37.4	477	37.4	482	36.5
Neither good nor bad	298	26.1	248	23.0	293	23.0	325	24.6
Bad	215	18.8	231	21.4	296	23.2	312	23.6
Recent change in field of study
No	866	75.9	848	78.5	960	75.3	954	72.3
Current tobacco consumption
No	783	68.6	708	65.6	840	65.9	844	63.9
Alcohol consumption
Never	124	10.9	115	10.6	107	8.4	102	7.7
Several times per year	251	22.0	235	21.8	245	19.2	236	17.9
Once a month	185	16.2	184	17.0	225	17.6	226	17.1
Once a week or less	344	30.1	364	33.7	436	34.2	443	33.6
More than twice a week	237	20.8	182	16.9	262	20.5	313	23.7
Cannabis consumption
No	549	48.1	471	43.6	562	44.1	527	39.9
Consumption of other drugs
No	947	83.0	913	84.5	1032	80.9	1047	79.3

Numbers may not add to 100% due to rounding values.

*ADHD score categorised in quintiles according to Kessler et al.²⁰

ADHD, Attention Deficit Hyperactivity Disorder.