Table 3.
Effect sizes for associations between delirium measures and outcomes. ∗Models were adjusted for age, sex, ASA class, number of comorbid conditions, history of falls, cardiac surgery, abnormal preoperative Short Blessed Test (score >4), preoperative functional capacity <4 metabolic equivalents, length of anaesthesia, and units of packed red blood cells transfused intraoperatively. †Effect sizes for mortality and falls are absolute risk differences (marginal effects from logistic regression models). Effect sizes for PCS-12 and MCS-12 are differences in medians from quantile regression. See Supplementary Table S8 for 95% confidence interval (CI). ‡All models for postoperative PCS-12 were adjusted for the preoperative PCS-12 value. All models for postoperative MCS-12 were adjusted for the preoperative MCS-12 value. IQR, inter-quartile range; PCS-12, Veterans RAND 12-Item Health Survey physical composite summary; MCS-12, Veterans RAND 12-Item Health Survey mental composite summary; CAM-S, Confusion Assessment Method – Severity; NA, not available.
| Incidence (%) or median [IQR] |
Unadjusted |
Adjusted∗ |
||||
|---|---|---|---|---|---|---|
| With predictor | Without predictor | Effect size (99.5% CI)† | P | Effect size (99.5% CI)† | P | |
| Mortality | ||||||
| Any delirium | 47/283 (16.6%) | 72/909 (7.9%) | 7.4% (2.3%–12.5%) | <0.001 | 4.6% (–0.9% to 10.2%) | 0.020 |
| Severe delirium | 18/118 (15.3%) | 86/1039 (8.3%) | 5.6% (–0.8% to 12.1%) | 0.014 | 3.9% (–3.2% to 10.9%) | 0.124 |
| Max CAM-S (per point) | N/A | N/A | 1.1% (0.4%–1.8%) | <0.001 | 0.9% (0.1%–1.6%) | 0.002 |
| Days of delirium (per day) | N/A | N/A | 3.1% (1.2%–5.0%) | <0.001 | 2.3% (0.2%–4.4%) | 0.002 |
| Falls | ||||||
| Any delirium | 73/203 (36.0%) | 198/750 (26.4%) | 9.1% (–0.4% to 18.5%) | 0.007 | 5.5% (–4.7% to 15.8%) | 0.130 |
| Severe delirium | 34/84 (40.5%) | 234/852 (27.5%) | 11.9% (–1.4% to 25.1%) | 0.012 | 10.7% (–3.4% to 24.8%) | 0.033 |
| Max CAM-S (per point) | N/A | N/A | 1.9% (0.6%–3.2%) | <0.001 | 1.3% (–1.7% to 2.8%) | 0.013 |
| Days of delirium (per day) | N/A | N/A | 5.3% (1.1%–9.5%) | <0.001 | 4.2% (–0.3% to 8.7%) | 0.009 |
| PCS-12‡ | ||||||
| Any delirium | 39.5 [28.6–48.6] | 45.3 [32.8–53.1] | –1.8 (–5.4 to 1.8) | 0.157 | –2.1 (–6.0 to 1.7) | 0.122 |
| Severe delirium | 39.1 [26.2–49.6] | 44.6 [32.8–52.5] | –2.4 (–6.6 to 1.9) | 0.116 | –2.4 (–8.4 to 3.6) | 0.267 |
| Max CAM-S (per point) | N/A | N/A | –0.3 (–0.8 to 0.1) | 0.037 | –0.5 (–1.0 to 0.0) | 0.006 |
| Days of delirium (per day) | N/A | N/A | –1.0 (–2.6 to 0.7) | 0.105 | –1.5 (–3.0 to 0.1) | 0.007 |
| MCS-12‡ | ||||||
| Any delirium | 55.5 [45.1–60.9] | 58.9 [52.5–62.2] | –1.3 (–3.3 to 0.7) | 0.061 | –1.2 (–3.7 to 1.4) | 0.200 |
| Severe delirium | 52.9 [40.3–60.2] | 58.5 [51.8–62.0] | –2.5 (–7.8 to 2.8) | 0.181 | –2.0 (–7.0 to 2.9) | 0.248 |
| Max CAM-S (per point) | N/A | N/A | –0.4 (–0.6 to –0.1) | <0.001 | –0.3 (–0.7 to 0.1) | 0.035 |
| Days of delirium (per day) | N/A | N/A | –0.8 (–2.2 to 0.6) | 0.098 | –0.6 (–2.1 to 0.8) | 0.232 |