Groggy mornings were linked to falls. Daytime sleepiness, less clearly.

Cross-sectional study. 392 people. one study visit (2019-2023); falls recalled over the previous 12 months.

One snapshot in time. Nobody was told what to do. A clue, not proof.

Who: Non-shift-working adults aged 60+ in the Wisconsin Sleep Cohort (originally Wisconsin state employees, oversampled for sleep apnea risk); mean age 74.5 (SD 6.6); 44.9% women; 96.2% White; 392 in the recurrent-falls analysis, 162 (those with 1+ fall) in the injurious-falls analysis

• Very groggy morningshigherodds of 2+ falls
• Sleepy in the daytimeunclearafter adjusting
• Falls with injuryunclearafter adjusting

More to know, from our read of the paper:

• Cross-sectional and observational: one visit, cannot show grogginess causes falls; authors say it may also be a marker of broader health problems
• Everything self-reported: sleep inertia (SIQ, typical morning in the past week), sleepiness (Epworth), falls and injuries recalled over the past year. Different time windows for exposure and outcome
• Timing of falls not recorded, so we cannot say falls happened in the morning or after waking
• 'Elevated sleep inertia' = top quartile (SIQ > 37) of THIS sample; no established clinical cut-off
• Injurious falls: sleep inertia linked only before full adjustment (fully adjusted OR 1.98, 0.82-4.91, p=0.13); Epworth sleepiness never linked to injurious falls

Researchers surveyed 392 adults aged 60 and over (average age 74.5) from the Wisconsin Sleep Cohort about morning grogginess (sleep inertia), daytime sleepiness and falls in the past year. The groggiest quarter had higher odds of two or more falls, even after adjusting for age, sleep, mood, balance and more. Daytime sleepiness was linked at first but not clearly after full adjustment, and neither was clearly linked to falls with an injury once everything was adjusted. It was a one-time, self-reported survey: linked, not proven.

We read the abstract and the full text of this paper and checked every number on this page against it (17 facts, checked on 2026-10-29). The study design is named above. Cohort and other observational studies are described as linked, not proven. Found an error? Email theis@onestudyaday.com.