Table. Rest-Activity Rhythm Characteristics by Cluster (N = 1800).
| Characteristic | Cluster 1: earlier rising/robust | Cluster 2: shorter active period/less modelable | Cluster 3: shorter active period/very weak | Cluster 4: later settling/very weak |
|---|---|---|---|---|
| No. in cluster | 677 | 587 | 177 | 359 |
| Cluster prevalence, % | 37.6 | 32.63 | 9.83 | 19.96 |
| Sociodemographic factors | ||||
| Age, mean (SD), y | 72.3 (5.3) | 72.8 (5.3) | 74.0 (5.1) | 73.5 (5.6) |
| Sex, weighted % | ||||
| Female | 63.2 | 55.0 | 48.8 | 50.6 |
| Male | 36.8 | 45.0 | 51.2 | 49.4 |
| Race and ethnicity, weighted % | ||||
| Asian | 4.1 | 2.1 | 3.4 | 3.4 |
| Black | 5.3 | 6.6 | 12.4 | 13.5 |
| Hispanic | 5.9 | 6.2 | 9.6 | 5.9 |
| White/other/mixed | 84.8 | 85.1 | 74.6 | 77.3 |
| Education, weighted %a | ||||
| < High school | 15.4 | 20.4 | 29.2 | 20.2 |
| High school | 21.5 | 24.2 | 19.0 | 22.6 |
| Some college | 27.0 | 33.1 | 33.8 | 30.7 |
| College degree or more | 36.1 | 22.2 | 18.0 | 26.5 |
| Activity pattern factors, mean (SD), original units | ||||
| Activity onset timeb | 6.8 (0.8) | 7.6 (1.2) | 7.9 (1.9) | 7.1 (1.7) |
| Activity offset time | 22.0 (1.2) | 21.0 (1.6) | 19.8 (3.3) | 22.3 (1.8) |
| Active period duration, mean (SD), hc | 15.2 (1.1) | 13.4 (1.5) | 11.8 (3.2) | 15.2 (1.4) |
| Pseudo–F statistic | 5.8 (0.5) | 4.7 (0.7) | 3.9 (1.3) | 5.6 (0.6) |
| Amplitudec | 2.5 (0.3) | 2.4 (0.3) | 2.2 (0.5) | 2.2 (0.4) |
| Interdaily stability | 0.4 (0.1) | 0.4 (0.1) | 0.3 (0.1) | 0.3 (0.1) |
| Relative amplitude | 0.9 (0) | 0.9 (0) | 0.8 (0.1) | 0.8 (0.1) |
| Intradaily variability | 0.4 (0.1) | 0.4 (0.1) | 0.5 (0.1) | 0.5 (0.1) |
| Activity pattern factors, mean (SD), standardized units | ||||
| Activity onset time | −0.3 (0.6) | 0.3 (0.9) | 0.5 (1.4) | −0.1 (1.2) |
| Activity offset time | 0.2 (0.6) | −0.3 (0.8) | −0.9 (1.6) | 0.4 (0.9) |
| Active period duration, hc | 0.4 (0.5) | −0.4 (0.7) | −1.2 (1.5) | 0.4 (0.7) |
| Pseudo–F statistic | 0.6 (0.5) | −0.5 (0.7) | −1.3 (1.3) | 0.4 (0.6) |
| Amplitudec | 0.4 (0.7) | 0.2 (0.9) | −0.5 (1.4) | −0.4 (1.0) |
| Interdaily stability | 0.4 (0.8) | 0.1 (0.9) | −0.5 (1.2) | −0.4 (0.9) |
| Relative amplitude | 0.7 (0.3) | 0.4 (0.5) | −0.9 (1.4) | −0.7 (0.8) |
| Intradaily variability | −0.3 (0.7) | −0.2 (0.8) | 0.6 (1.4) | 0.4 (1.0) |
a
Self-reported other race and ethnicity indicates American Indian or Alaskan Native, Native Hawaiian or Pacific Islander.
b
Times are in 24-hour decimal time, eg, 6.5 = 06:30 am
c
Indicates that the variable was not included in the clustering, owing to high correlations and redundancy with others that were (shown for illustrative purposes).