Table 2.
Associations between exercise HRR group and delirium incidence.
| Average HRR index (n = 19,575) |
Low HRR index (n = 10,111) |
|||||
|---|---|---|---|---|---|---|
| Hazard ratio (95%CI) | p | Hazard differencea | Hazard ratio (95%CI) | p | Hazard differencea | |
| Delirium incidence, all settings (n = 348) | ||||||
| Model 1 | 1.60 (1.09 – 2.23) | 0.01 | — | 2.24 (1.56 – 3.22) | <0.001 | — |
| Model 2 | 1.59 (1.11 – 2.29) | 0.01 | –0.01 | 2.22 (1.53 – 3.24) | <0.001 | –0.02 |
| Model 3 | 1.57 (1.09 – 2.26) | 0.01 | –0.02 | 2.05 (1.41 – 2.98) | <0.001 | –0.17 |
| Model 4 | 1.54 (1.07 – 2.22) | 0.02 | –0.03 | 1.90 (1.30 – 2.79) | 0.001 | –0.15 |
| Postoperative deliriumb(n = 147) | ||||||
| Model 1 | 1.53 (0.81 – 2.52) | 0.21 | — | 2.87 (1.64 – 5.02) | <0.001 | — |
| Model 2 | 1.53 (0.85 – 2.74) | 0.15 | 0 | 2.89 (1.61 – 5.20) | <0.001 | +0.02 |
| Model 3 | 1.53 (0.85 – 2.75) | 0.15 | 0 | 2.75 (1.53 – 4.96) | <0.001 | –0.14 |
| Model 4 | 1.52 (0.84 – 2.73) | 0.16 | –0.01 | 2.66 (1.46 – 4.85) | 0.001 | –0.09 |
| Non-dementia-related deliriumc(n = 294) | ||||||
| Model 1 | 1.56 (1.06 – 2.29) | 0.02 | — | 2.29 (1.55 – 3.38) | <0.001 | — |
| Model 2 | 1.54 (1.04 – 2.26) | 0.02 | –0.02 | 2.13 (1.43 – 3.18) | <0.001 | –0.16 |
| Model 3 | 1.51 (1.03 – 2.22) | 0.03 | –0.03 | 1.97 (1.32 – 2.95) | <0.001 | –0.16 |
| Model 4 | 1.49 (1.01 – 2.19) | 0.04 | –0.02 | 1.87 (1.25 – 2.82) | 0.002 | –0.10 |
Notes: Delirium incidence was estimated using hospitalization data. Participants in the top quartile (high) HRR index were used as reference. All analyses were done using a 2-year landmark analysis, excluding participants who experienced events prior to or within the first 2 years of follow-up (n = 69). Model 1 included sociodemographic variables (age, sex, education, ethnicity, and deprivation). Model 2 further included lifestyle factors (physical activity, body mass index, smoking, and alcohol intake). Model 3 further included CVD risk score (high blood pressure, cholesterol, diabetes, ischemic heart disease, and peripheral vascular disease), HR-control medications, morbidity burden, and reaction time at baseline. Model 4 included the final adjustment made for maximal METs achieved.
Abbreviations: 95%CI = 95% confidence interval; CVD = cardiovascular disease; HRR = heart rate response/recovery; MET = metabolic equivalent of task.
Risk difference from prior model.
Operation occurring within 3 days prior.
After exclusion of delirium superimposed on dementia.