Table 1.
Sample characteristics and dropout analysis.
| Participated only at T1 N = 6,019 | Participated at T1 and T2, N = 5,217 | Significance test and effect size of differences | |
|---|---|---|---|
| Mean (SD) / % (95% CI) | Mean (SD) / % (95% CI) | ||
| DEMOGRAPHICS | |||
| Age at T2 (i.e., age at T1 + 1 year) | 26.0 (6.6) | 25.8 (6.3) | Cohen's d = 0.025E, N.S., 2 |
| Women | 62.1% (60.8–63.3%) | 64.8% (63.5–66.1%) | Phi = 0.028N.E,** |
| Born in Norway | 92.2% (91.5–92.9%) | 92.7% (92.0–93.4%) | Phi = 0.010E., N.S. |
| Single at T1 | 47.6% (46.3–48.9%) | 46.9% (45.6–48.2%) | Phi = 0.007E., N.S. |
| Parent at T1 | 11.9% (11.0–12.7%) | 11.1% (10.2–11.9%) | Phi = 0.012E., N.S. |
| Religious at T1 | 36.0% (34.7–37.2%) | 33.4% (32.2–34.7%) | Phi = 0.026N.E,** |
| Student at T2 | – | 83.7% (82.7–84.8%) | – |
| PERSONALITYa | |||
| Extroversion | 14.1 (3.6) | 14.0 (3.7) | Cohen's d = 0.029N.E., N.S., 1 |
| Agreeableness | 16.8 (2.8) | 16.9 (2.8) | Cohen's d = 0.055N.E.,** |
| Conscientiousness | 14.6 (3.2) | 14.7 (3.2) | Cohen's d = 0.030N.E., N.S., 1 |
| Neuroticism | 11.1 (3.6) | 11.0 (3.7) | Cohen's d = 0.021E., N.S., 2 |
| Intellect/imagination | 14.6 (3.2) | 14.6 (3.2) | Cohen's d = 0.001E., N.S., 1 |
| SELF-MONITORINGb | |||
| Self-monitoring score | 40.0 (7.7) | 40.1 (7.9) | Cohen's d = 0.012E., N.S., 2 |
| ALCOHOL USEc | |||
| AUDIT-score T1 | 8.2 (4.9) | 8.2 (4.9) | Cohen's d = 0.013E., N.S., 1 |
| AUDIT-score T2 | – | 7.5 (4.7) | – |
| Change in AUDIT-score (T2-T1) | – | – 0.6 (3.0) | – |
| Risky drinking (8 ≤ AUDIT, T1) | 53.0% (51.7–54.4%) | 53.0% (51.6–54.4%) | Phi = 0.000E., N.S. |
| Risky drinking (8 ≤ AUDIT, T2) | – | 47.0% (45.6–48.4%) | – |
| ALCOHOL-RELATED COGNITIONS | |||
| Prototypic apprehension of the typical heavy drinker (T1)d | 5.0 (1.4) | 5.0 (1.4) | Cohen's d = 0.030N.E., N.S., 1 |
| Number of 5 closest co-students that drinks a couple of times a week (T1) | 1.9 (1.5) | 1.9 (1.5) | Cohen's d = 0.004E., N.S., 1 |
| Number of 5 closest co-students that typically drink 10 alcohol units or more (T1) | 0.8 (1.2) | 0.7 (1.2) | Cohen's d = 0.063N.E.,**, 2 |
| Number of 5 closest co-students that drink 6 units or more a couple of times a week (T1) | 1.0 (1.3) | 0.9 (1.3) | Cohen's d = 0.044 N.E., *, 2 |
| Prototypic apprehension of the typical sharer of alcohol-related content on social media (T1)d | 4.7 (1.4) | 4.7 (1.4) | Cohen's d = .016E., N.S., 1 |
| Number of 5 closest online-friends that drinks a couple of times a week (T1) | 1.8 (1.4) | 1.8 (1.5) | Cohen's d = .012E., N.S., 1 |
| Number of 5 closest online-friends that typically drink 10 alcohol units or more (T1) | 0.94 (1.3) | 0.86 (1.2) | Cohen's d = 0.064N.E, **, 2 |
| Number of 5 closest online-friends that drink 6 units or more a couple of times a week (T1) | 1.1 (1.3) | 1.0 (1.3) | Cohen's d = 0.058N.E, **, 2 |
| SOCIAL MEDIA USE AND ALCOHOL-RELATED DISCLOSURE AND EXPOSURE | |||
| Frequency of login to social mediae | 6.6 (1.0) | 6.7 (0.9) | Cohen's d = 0.042N.E., *, 2 |
| Number of online-friends | 460.0 (272.6) | 454.0 (264.3) | Cohen's d = 0.023E., N.S., 2 |
| Have a Snapchat-account | 87.6% (86.7–88.5%) | 88.7% (87.8–89.6%) | Phi = 0.018N.E., N.S. |
| Frequent disclosure of content reflecting positive aspects of alcohol (T1)f | 9.4% (8.5–10.2%) | 9.6% (8.7–10.4%) | Phi = 0.004E., N.S. |
| Frequent disclosure of content reflecting negative aspects of alcohol (T1)f | 2.4% (2.0–2.9%) | 2.8% (2.3–3.2%) | Phi = 0.010E., N.S. |
| Frequent exposure to content reflecting positive aspects of alcohol (T1)f | 77.1% (75.9–78.3%) | 78.8% (77.6–80.0%) | Phi = 0.021N.E., * |
| Frequent exposure to content reflecting negative aspects of alcohol (T1)f | 38.1% (36.7–39.4%) | 39.4% (38.0–40.8%) | Phi = 0.014E., N.S. |
SD Standard deviation, CI Confidence interval, T1 The time of the first wave, T2 The time of the second wave, AUDIT Alcohol Use Disorder Identification Test, 1Equal variance assumed, 2Equal variance not assumed, E. Equivalent, N.E. Not equivalent, N.S. Not significant,
*
p < 0.05,
**
p < 0.01,
***
p < 0.001.
a
Total scores range 5–20 for each trait.
b
Total scores range 0–65.
c
Total scores range 0–40.
.d
Response alternatives = 0 (extremely negative)−10 (extremely positive).
e
1 = Seldom/never, 2 = Less than once a week, 3 = 1 time a week, 4 = 2–3 times a week, 5 = 4–6 times a week, 6 = 1–2 times a day, 7 = Over 3 times a day.
f
Frequent = Monthly or more often.