Sleep and daytime problems among all participants in the International COVID-19 Sleep Study study (N=25 484).
| All countries | Before pandemic (CI) | During pandemic (CI) | Improved | Unchanged | Worsened |
| Poor sleep quality* | 12.5% (11.8% to 13.2%) | 28.2% (27.1% to 29.3%)† | 5.2% | 74.0% | 20.8% |
| Sleep onset problems‡ | 14.8% (13.9% to 15.7%) | 27.9% (26.9% to 29.1%)† | 4.4% | 77.8% | 17.8% |
| Sleep maintenance problems§ | 17.1% (16.2% to 18.1%) | 27.9% (26.8% to 29.1%)† | 4.2% | 80.6% | 15.2% |
| Early morning awakening¶ | 13.6% (12.7% to 14.5%) | 21.7% (20.6% to 22.7%)† | 5.0% | 81.8% | 13.2% |
| Nightmares** | 8.5% (7.7% to 9.4%) | 15.0% (14.0% to 16.0%)† | 2.9% | 87.6% | 9.5% |
| Hypnotic use†† | 7.8% (7.1% to 8.6%) | 12.2% (11.2% to 13.2%)† | 2.4% | 90.7% | 6.9% |
| Fatigue‡‡ | 20.7% (19.8% to 21.7%) | 29.9% (28.8% to 31.0%)† | 8.0% | 74.9% | 17.1% |
| Excessive sleepiness§§ | 18.5% (17.6% to 19.5%) | 27.7% (26.6% to 28.9%)† | 6.9% | 76.9% | 16.2% |
*Proportion reporting sleep quality ‘rather badly’ or ‘badly’.
†Statistically significant difference from before pandemic (p<0.0001).
‡Proportion reporting sleep onset problems 3+ days/week.
§Proportion reporting sleep maintenance problems 3+ day/week.
¶Proportion reporting early morning awakening problems 3+ days/week.
**Proportion reporting nightmares 3+ nights/week.
††Hypnotic use 3+ days/week.
‡‡Proportion reporting fatigue 3+ days/week.
§§Proportion reporting excessive daytime sleepiness 3+ days/week.