Table 2. Falls Incidence Rate Ratios by Minutes per day of Accelerometer-Measured Physical Activity.
| Minutes per day in accelerometer-measured physical activity (quartiles) | |||||
|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | P for trend | |
| MVPA quartile ranges [mean minutes (SD) =51 (35)] | <25.1 | 25.1-<44.1 | 44.1-<69.3 | ≥ 69.3 | |
| Number of Falls | 1659 | 1375 | 1240 | 1190 | |
| Person-Months | 14443 | 15365 | 15631 | 16117 | |
| Crude falls rate per 1000 PM | 114.9 | 89.5 | 79.3 | 73.8 | |
| Model 1 a, IRR (95% CI) | 1.43 (1.24-1.65) | 1.11 (0.97-1.27) | 1.05 (0.92-1.19) | 1.0 (Ref) | <0.001 |
| Model 2 b, IRR (95% CI) | 1.18 (1.01-1.38) | 1.01 (0.87-1.16) | 0.98 (0.86-1.13) | 1.0 (Ref) | 0.04 |
| Light activity quartile ranges [mean minutes (SD) = 288 (77)] | <233.2 | 233.2-<286.2 | 286.2-<337.4 | ≥ 337.4 | |
| Number of Falls | 1535 | 1325 | 1272 | 1332 | |
| Person-Months | 14723 | 15463 | 15631 | 15739 | |
| Crude falls rate per 1000 PM | 104.3 | 85.7 | 81.4 | 84.6 | |
| Model 1 a, IRR (95% CI) | 1.12 (0.98-1.29) | 0.92 (0.80-1.04) | 0.93 (0.82-1.06) | 1.0 (Ref) | 0.12 |
| Model 2 b, IRR (95% CI) | 1.09 (0.93-1.27) | 0.99 (0.86-1.14) | 1.02 (0.89-1.17) | 1.0 (Ref) | 0.38 |
| Total activity quartile ranges [mean minutes (SD) = 339 (97)] | <270.7 | 270.7-<335.7 | 335.7-<402.0 | ≥ 402.0 | |
| Number of Falls | 1585 | 1327 | 1305 | 1247 | |
| Person-Months | 14688 | 15267 | 15581 | 16020 | |
| Crude falls rate per 1000 PM | 107.9 | 86.9 | 83.8 | 77.8 | |
| Model 1 a, IRR (95% CI) | 1.25 (1.09-1.43) | 1.02 (0.89-1.16) | 1.03 (0.91-1.18) | 1.0 (Ref) | 0.004 |
| Model 2 b, IRR (95% CI) | 1.20 (1.03-1.40) | 1.01 (0.88-1.17) | 1.10 (0.96-1.26) | 1.0 (Ref) | 0.07 |
a
Adjusted for age, race/ethnicity, education, and wear time.
b
Adjusted for age, race/ethnicity, education, wear time, vision, body pain, alcohol use, sleep aid use, body mass index, and chronic conditions. Abbreviations: CI, confidence interval; IRR, incidence rate ratio; MVPA, moderate/vigorous physical activity; PM, person-months; Q, quartile; SD, standard deviation. Cutpoint values for moderate/vigorous, light, and total physical activity are vector magnitude counts of ≥519, 19-518, and ≥19 per 15-seconds, respectively. Excludes one participant with 327 verified falls.