Table 1. Independent variables included in the study and data analysis.
| Behaviors and habits | Independent variable |
|---|---|
| Sleeping habits | |
| Hours of sleep per night | Average number of hours slept per night (categorical data: 4 h or less; 5 h; 6 h; 7 h; 8 h; 9 h; 10 h or more per night) |
| Average time going to bed | Average time of night going to bed (categorical data: before 8pm; between 8pm and 10pm; between 10pm and 12am; after 2am) |
| Working | |
| Do you work? | Categorical data (Yes; No) |
| Average hours worked per week | Average number of hours worked per week (categorical data: [including all students who did not work]; under 5 h; 5–10 h; 10–20 h; 20–30 h; 30–40 h; over 40 h) |
| Physical activity | |
| Physical activity | Number of days per week with physical activity of at least 60 min (continuous numerical data, range: 0 to 7 days) |
| Strength training | Number of days per week doing exercises to strengthen or tone muscles (continuous numerical data, range: 0 to 7 days) |
| Eating habits | |
| Consumption of vegetables | Number of times vegetables consumed in past 7 days (categorical data: 0 times; 1 to 3 times; 4 to 6 times; 7 to 10 times; 11 times or more) |
| Consumption of fruit | Number of times fruit consumed in past 7 days (categorical data: 0 times; 1 to 3 times; 4 to 6 times; 7 to 10 times; 11 times or more) |
| Breakfast consumption | Number of days breakfast eaten in past 7 days (continuous numerical data, range: 0 to 7 days) |
| Fast food consumption | Number of times fast food consumed in past 7 days (categorical data: 0 times; 1 to 3 times; 4 to 6 times; 7 to 10 times; 11 times or more) |
| Coffee consumption | Number of cups of coffee consumed per day (categorical data: 0 cups, 1-2 cups, 3-4 cups, 5-6 cups, 7 cups or more) |
| Online activity | |
| Time spent watching TV, movies, reading news online | Number of hours per day (categorical data: 0 h, less than 1 h, 1 h, 2 h, 3 h, 4 h, 5 h or more) |
| Time spent playing video or computer games | Number of hours per day (categorical data: 0 h, less than 1 h, 1 h, 2 h, 3 h, 4 h, 5 h or more) |
| Vaping, alcohol and marijuana | |
| Vaping | Number of days vaping in past 7 days (continuous numerical data, range: 0 to 7 days) |
| Alcohol consumption | Number of days consuming at least one drink during the last 30 days (categorical data: 0 days, 1–2 days, 3–5 days, 6–9 days, 10–19 days, 20–29 days, all 30 days) |
| Marijuana use | Number of days using marijuana in past 7 days (continuous numerical data, range: 0 to 7 days) |
| Mental/emotional health | |
| Difficulties concentratinga | Categorical data (Yes; No) |
| Feeling sad or hopelessb | Categorical data (Yes; No) |
| Considered suicidec | Categorical data (Yes; No) |
| Number of times suicide consideredd | Number of times over past 12 months (categorical data: 1 time, 2-3 times, 4-5 times, 6 times or more) |
| Planned suicidee | Categorical data (Yes; No) |
| Attempted suicidef | Categorical data (Yes; No) |
Notes.
a
Do you have serious difficulty concentrating, remembering, or making decisions because of a physical, mental, or emotional problem?
b
During the past 12 months, did you ever feel so sad or hopeless almost every day for two weeks or more in a row that you stopped doing some usual activities?
c
During the past 12 months, did you ever seriously consider attempting suicide?
d
How many times did you consider attempting suicide?
e
Did you make a plan about how you would attempt suicide?
f
Did you actually attempt suicide?