Table 2.
A descriptive table showing the means, standard deviations, medians, and interquartile ranges for all variables for good and poor sleepers as indicated from the PSQI. The table also shows p values comparing good and poor sleepers using either independent samples t-test. Mann Whitney U test and chi square tests. Participants with good sleep quality had PSQI global scores of less than 5 and participants with poor sleep quality had PSQI global scores of greater than 5.
| Good Sleep Quality n = 35 |
Poor Sleep Quality n = 45 |
p Values | |||
|---|---|---|---|---|---|
| Mean (SD) | Median (IQR) | Mean (SD) | Median (IQR) | ||
| Total caffeine (mg) | 130.0 (62.6) | 123.2 (58.2) | 192.1 (122.5) | 140.4 (160.6) | 0.008 I |
| Coffee (mg) | 81.7 (68.5) | 66.5 (83.1) | 132.2 (115.0) | 99.2 (83.3) | 0.019 M |
| Tea (mg) | 35.4 (48.4) | 13.6 (54.3) | 39.5 (61.5) | 13.6 (55.0) | 0.874 M |
| Chocolate (mg) | 3.6 (4.0) | 1.7 (4.5) | 3.5 (4.9) | 1.7 (4.5) | 0.658 M |
| Soft Drink (mg) | 6.5 (13.2) | 0.0 (5.2) | 10.9 (29.2) | 0.0 (10.4) | 0.368 M |
| Energy drink (mg) | 2.9 (15.4) | 0.0 (0.0) | 6.0 (23.0) | 0.0 (0.0) | 0.395 M |
| SOL (min) | 11.4 (7.6) | 10.0 (13.0) | 24.3 (11.0) | 30.0 (15.0) | 0.000 C |
| SE (%) | 95.0 (4.6) | 94.1 (8.6) | 82.9 (8.8) | 82.4 (11.1) | 0.239 M |
| TIB (h) | 7.9 (0.7) | 8.0 (1.3) | 8.2 (1.2) | 8.0 (1.1) | 0.000 C |
Abbreviations: SD, standard deviation; PSQI, Pittsburgh Sleep Quality Index; IQR, interquartile range; mg, milligrams; SOL, sleep onset latency; SE, sleep efficiency; TIB, time in bed; global score, PSQI total score; %, percentage; I, Independent samples t-test was used; M, Mann-Whitney U test was used; C, Chi-square test was used. Notes: Chocolate includes both food and drink.