| Objective sleep parameters | Number of posture shifts | |
| Younger group | Senior group | |
| Total minutes scored as awake (TMSA) | n.s. | 0.36* |
| Wake after sleep on set (WASO) | n.s. | 0.48* |
| Sleep efficiency (SE) | n.s. | −0.47** |
| Sleep on set latency (SOL) | n.s. | n.s. |
| Activity index (ACTX) | 0.48** | 0.37* |
| Sleep fragmentation Index (SFX) | n.s. | 0.38* |
| Wake episodes (WEP) | 0.38** | 0.44* |
| Long wake episodes (LWEP) | n.s. | n.s. |