Table 2.
Associations of rest-activity parameters and likelihood of recurrent falls (≥2 in 1 year of follow-up)
| Predictor | Model | Odds Ratio (95 % Confidence Interval) | |||
|---|---|---|---|---|---|
| Events N (%) |
Age+Site Adjusted | Multivariable Adjusted* | Multivariable + Activity Adjusted** | ||
| Amplitude | Continuous per SD decrease (−1090 counts/min) Quintiles |
417 (14.03) | 1.21 (1.08, 1.36) | 1.07 (0.95, 1.20) | 1.11 (0.95, 1.31) |
| Q1:<2730.71 | 107 (18.20) | 1.60 (1.13, 2.27) | 1.09 (0.75, 1.58) | 1.08 (0.65, 1.80) | |
| Q2:2730.71 to <3315.83 | 92 (15.41) | 1.41 (0.99, 2.01) | 1.35 (0.93, 1.94) | 1.35 (0.88, 2.05) | |
| Q3:3315.83 to <3778.50 | 82 (13.71) | 1.25 (0.88, 1.79) | 1.17 (0.81, 1.70) | 1.17 (0.79, 1.73) | |
| Q4:3778.50 to <4361.92 | 76 (12.73) | 1.23 (0.86, 1.77) | 1.28 (0.88, 1.85) | 1.27 (0.87, 1.84) | |
| Q5:≥4361.92 | 60 (10.12) | reference | reference | reference | |
| P-trend | 0.0069 | 0.6684 | 0.6309 | ||
| Mesor | Continuous per SD decrease (−502 counts/min) Quintiles |
417 (14.03) | 1.11 (0.99, 1.24) | 1.01 (0.91, 1.14) | 1.02 (0.88, 1.19) |
| Q1:<1789.82 | 100 (16.92) | 1.28 (0.91, 1.79) | 0.94 (0.66, 1.34) | 0.76 (0.46, 1.23) | |
| Q2:1789.82 to <2030.22 | 78 (13.11) | 1.00 (0.71, 1.42) | 0.93 (0.64, 1.33) | 0.81 (0.54, 1.24) | |
| Q3:2030.22 to <2235.98 | 78 (13.02) | 1.04 (0.73, 1.47) | 0.99 (0.69, 1.41) | 0.92 (0.62, 1.34) | |
| Q4:2235.98 to <2500.61 | 91 (15.29) | 1.27 (0.90, 1.77) | 1.28 (0.90, 1.81) | 1.23 (0.87, 1.76) | |
| Q5:≥2500.61 | 70 (11.80) | reference | reference | reference | |
| P-trend | 0.503 | 0.2405 | 0.0783 | ||
| Acrophase | Continuous per SD increase (1 hr, 12 min) | 417 (14.03) | 1.23 (1.11, 1.36) | 1.18 (1.06, 1.32) | 1.18 (1.06, 1.32) |
| <1:04PM | 52 (12.56) | 0.90 (0.65, 1.24) | 0.86 (0.62, 1.20) | 0.86 (0.62, 1.21) | |
| 1:04–3:29PM | 282 (13.11) | reference | reference | reference | |
| >3:29PM | 83 (20.34) | 1.67 (1.27, 2.21) | 1.46 (1.08, 1.97) | 1.46 (1.08, 1.97) | |
| Pseudo-F statistic | Continuous per SD decrease (−512.9) Quintiles |
417 (14.03) | 1.24 (1.10, 1.40) | 1.12 (0.99, 1.27) | 1.23 (1.04, 1.46) |
| Q1:<640.319 | 111 (18.91) | 1.68 (1.19, 2.36) | 1.27 (0.88, 1.84) | 1.53 (0.95, 2.47) | |
| Q2:640.319 to <853.460 | 86 (14.41) | 1.25 (0.88, 1.78) | 1.11 (0.77, 1.61) | 1.27 (0.83, 1.94) | |
| Q3:853.460 to <1092.75 | 88 (14.72) | 1.35 (0.95, 1.91) | 1.33 (0.93, 1.91) | 1.48 (1.00, 2.20) | |
| Q4:1092.75 to <1415.08 | 68 (11.41) | 1.02 (0.70, 1.46) | 1.06 (0.73, 1.53) | 1.13 (0.77, 1.66) | |
| Q5:≥1415.08 | 64 (10.76) | reference | reference | reference | |
| P-trend | 0.0011 | 0.2109 | 0.1049 | ||
SD, standard deviation.
*
Adjusted for age, clinic site, race, body mass index, any medical condition (diabetes mellitus, coronary heart disease, hypertension, stroke), smoking, alcohol use, caffeine use, depression, use of benzodiazepines, use of prescription sleep medications, presence of an IADL, walking speed, nocturia.
**
In secondary analyses, models were further adjusted for activity level to examine if associations between RAR parameters and falls were independent of physical activity.