Table 3.
Adjusted Pre-Post Association of Intervention on RCSQ Overall and Noise Ratings
| Variable | Overall Sleep Qualitya | P Value | Noiseb | P Value |
|---|---|---|---|---|
| Intervention vs preintervention | 3.4 (–5.2 to 11.5)b | .43 | 9.51 (1.1-17.5) | .02 |
| Project dayc | 0.1 (–0.1 to 0.3) | .39 | 0.02 (–0.2 to 0.2) | .81 |
| Days afterd | –0.2 (–0.4 to 0.1) | .20 | –0.07 (–0.3 to 0.2) | .58 |
| Age, per y | –0.1 (–0.3 to 0.0) | .09 | –0.03 (–0.2 to 0.1) | .72 |
| Female vs male | 0.5 (–4.1 to 5.2) | .82 | 0.6 (–4.0 to 5.3) | .79 |
| CCI, per point | –0.0 (–0.9 to 0.8) | .93 | –0.2 (–1.2 to 0.6) | .60 |
| History of sleep problem, yes vs no | –4.4 (–10.1 to 1.0) | .12 | –1.9 (–7.3 to 3.4) | .49 |
| Use television to sleep at home, vs Yes | ||||
| No | 0.2 (–5.8 to 6.2) | .96 | 1.2 (–4.5 to 7.2) | .70 |
| Unknown | –6.6 (–22.8 to 9.4) | .42 | 10.3 (–5.5 to 29.3) | .22 |
| Admission category | ||||
| Cardiology | 5.5 (–1.4 to 11.8) | .11 | 2.6 (–4.2 to 9.6) | .45 |
| Cardiothoracic surgery | –5.9 (–11.7 to –0.1) | .046 | –3.6 (–9.7 to 2.2) | .22 |
| Mechanical ventilation, yes | 6.8 (1.8-12.1) | .01 | –5.3 (–10.5 to 0.1) | .05 |
| Coma on first ICU assessment | 1.2 (–4.8 to 7.2) | .70 | –1 (–6.9 to 4.6) | .74 |
| Nurse vs patient completing the questionnaire | 1.1 (–8.5 to 10.6) | .82 | –5.9 (–17.0 to 4.6) | .27 |
| Other vs patient completing the questionnaire | 6.2 (–8.3 to 20.9) | .82 | –10 (–27.1 to 5.0) | .17 |
Data are presented as difference (95% CI). CCI = Charlson Comorbidity Index; RCSQ = Richards-Campbell Sleep Questionnaire.
Values represent adjusted difference in RCSQ ratings, on a 0 to 100 visual analog scale, with positive differences representing improved sleep quality ratings across preintervention and intervention periods. The overall sleep quality rating represents the average of five RCSQ items. 95% CIs were estimated using bootstrap percentile method with 2,000 samples.
Unadjusted P > .1 for each of the five RCSQ items: (1) depth, (2) latency (time to fall asleep), (3) number of awakenings, (4) efficiency (percent of time awake), and (5) quality.
A time measure inherent in segmented regression analysis. In this analysis, it represents the number of days from intervention (day 0). It is negative for days before intervention and positive for days after intervention. Its coefficient measures a time trend assuming no intervention at all.
A time measure inherent in segmented regression analysis. In our analyses, it is the number of days after intervention. For days after intervention, the value equals project days. For days before the intervention, it is 0 (so it has no effect). Its coefficient measures additional time trend after the intervention not accounted for by the effect of project days alone.