How much do hospitalized adults move? A systematic review and meta-analysis.

The studies used many different definitions of activity, so the review could not combine all activity duration outcomes. The meta-analysis had substantial heterogeneity, with I2 = 75%, so the 70 minute estimate should be read with caution. Quality scores ranged from 7 to 12, with a median of 10, and the lowest rated items were external validity, patient sampling, and recruitment methods. Many observation studies measured only daytime hours, so evening and night activity may have been missed. Observation sampling at brief intervals may miss short ambulation episodes, because ambulation episodes are often less than 2 minutes. Activity monitor accuracy may vary by device, outcome, body placement, and population, and monitors are not widely used in clinical practice. The search was limited to acute-care populations and to activity type and duration, so other measures such as steps taken may have been excluded. The review could not measure the effect of disease severity on activity type and duration. Because definitions and measurement methods varied, point estimates could not be examined for most activity subtypes and populations apart from standing or walking in medical inpatients. Including both human observation and activity monitors may have introduced bias, because observation studies were shorter but reported activity over a day.

The declaration says Dr. Fazio received research equipment donated by Leaf Healthcare Inc. outside this work. The supplied text does not state who funded the review.

Do not read the 70 minute estimate as a proven activity dose that improves outcomes. The estimate describes standing or walking time measured in existing studies, not an intervention effect.