Table 4.
Relative difference in sleep indicators between groups at 3-month follow-up for participants sleeping ≥6 hours/night
| Sleep measure | Baseline mean (SD) | 12-week follow-up mean (SD) | Unadjusted difference β (95 % CI)a | P-value | Adjusted difference β (95 % CI)b | P-value |
|---|---|---|---|---|---|---|
| Sleep quantity on work/school nights (hours/night) | ||||||
| Sleep/activity group | 6.62 (0.90) | 6.59 (0.95) | −0.006 (−0.467, 0.456) | 0.98 | 0.001 (−0.481, 0.483) | 1.00 |
| Smoking cessation group | 7.09 (0.90) | 6.87 (1.18) | ||||
| Sleep quantity on non-work/non-school nights (hours/night) | ||||||
| Sleep/activity group | 8.34 (1.54) | 8.45 (1.90) | −0.027 (−0.780, 0.726) | 0.94 | 0.027 (−0.719, 0.774) | 0.94 |
| Smoking cessation group | 8.53 (1.83) | 8.55 (1.68) | ||||
| Sleep quality scorec | ||||||
| Sleep/activity group | 16.59 (4.55) | 15.03 (4.12) | 0.517 (−1.305, 2.339) | 0.57 | 0.468 (−1.395, 2.332) | 0.62 |
| Smoking cessation group | 16.32 (5.52) | 14.43 (4.34) | ||||
SD Standard deviation, CI Confidence interval
n = 82
aAdjusted for baseline sleep
bAdjusted for baseline sleep, change in physical activity, smoking status at follow-up, daily text messaging usage, sex, educational attainment, and race
cSleep quality was assessed using 8 self-report items adapted from the PSQI; scores were the sum of participants' quantified responses for each item, with higher scores being indicative of poorer sleep quality (possible scores ranged from 8 to 32)