Table 1.
Effect of typhoid vaccine and placebo, on selected sleep parameters (n = 15)
| Selected sleep parameters a | Group mean | SE | t (df = 14) | Two-tailed significance, p value | r (effect size) |
|---|---|---|---|---|---|
| Sleep continuity measures | |||||
| Total sleep time | |||||
| Placebo | 426.1 | 13.0 | 3.354 | 0.005 | 0.62 |
| Typhoid vaccine | 410.7 | 12.2 | |||
| Sleep efficiency, % b | |||||
| Placebo | 94.3 | 0.8 | 3.171 | 0.007 | 0.65 |
| Typhoid vaccine | 91.5 | 1.0 | |||
| Wake after sleep onset | |||||
| Placebo | 25.5 | 3.5 | −3.183 | 0.007 | 0.65 |
| Typhoid vaccine | 38.8 | 4.8 | |||
| Total wake | |||||
| Placebo | 34.9 | 3.4 | −3.365 | 0.005 | 0.67 |
| Typhoid vaccine | 50.3 | 5.0 | |||
| Sleep stage transitions | |||||
| Placebo | 155.9 | 8.0 | |||
| Typhoid vaccine | 173.1 | 9.2 | −2.5 | 0.026 | 0.56 |
| No. of awakenings | |||||
| Placebo | 27.2 | 1.9 | −3.1 | 0.007 | 0.64 |
| Typhoid vaccine | 36.1 | 3.5 | |||
| Awakening index | |||||
| Placebo | 3.8 | 0.3 | |||
| Typhoid vaccine | 5.3 | 0.5 | −3.337 | 0.005 | 0.67 |
| Sleep onset latency | |||||
| Placebo | 9.4 | 1.2 | −0.851 | 0.4 | 0.22 |
| Typhoid vaccine | 11.6 | 2.6 | |||
| NREM sleep measures | |||||
| N 1 (stage 1) | |||||
| Placebo | 37.8 | 2.8 | −1.409 | 0.2 | 0.35 |
| Typhoid vaccine | 45.0 | 5.2 | |||
| N 2 (stage 2) | |||||
| Placebo | 140.7 | 8.8 | 1.167 | 0.3 | 0.30 |
| Typhoid vaccine | 133.0 | 8.2 | |||
| N3 (SWS) | |||||
| Placebo | 140.8 | 6.8 | 1.588 | 0.1 | 0.30 |
| Typhoid vaccine | 128.7 | 6.9 | |||
| REM sleep measures | |||||
| REM latency | |||||
| Placebo | 65.6 | 4.9 | −0.677 | 0.5 | 0.18 |
| Typhoid vaccine | 69.5 | 4.7 | |||
| REM sleep | |||||
| Placebo | 106.8 | 6.8 | 0.739 | 0.4 | 0.20 |
| Typhoid vaccine | 103.6 | 5.4 | |||
aSleep parameters expressed in minutes unless stated otherwise
bSleep efficiency % = actual sleep time/time in bed × 100
Abbreviations: NREM non-rapid eye movement, REM rapid eye movement, SWS slow wave sleep