title: Computerized monitoring of physical activity and sleep in postoperative abdominal surgery patients.
abstract: OBJECTIVE
  Assessment of early postoperative activity is important in the documentation of improvements of peri-operative care. This study was designed to validate computerized activity-based monitoring of physical activity and sleep (actigraphy) in patients after abdominal surgery.
  
  
  METHODS
  The study included twelve hospitalized patients after major abdominal surgery studied on day 2 to 4 after operation and twelve unhospitalized healthy volunteers. Measurements were performed for 24 consecutive hours. The actigraphy measurements were compared with self-reported activity- and sleep registration. The actigraphy output was obtained by the zero-crossing mode (ZCM) and time-above-threshold mode (TATM).
  
  
  RESULTS
  The overall results showed comparable mean agreement between actigraphy and self-reported activity registrations for patients of 80% (SD 12%) and volunteers of 84% (SD 6%) (p = 0.15). In both study groups, all correlation coefficients between actigraphy measurements and self-reported activity data were statistically significant (r, values for patients 0.4 to 0.8 and volunteers 0.6 to 0.9). A higher mean agreement between automated actigraphy sleep detection and self-reported sleep registration were found in the volunteers (85%, SD 15%) compared with the patients (77%, SD 11%) (p < 0.05). The mean activity value awake was higher in the volunteers than in the patients (p < 0.05).
  
  
  CONCLUSIONS
  Computerized activity monitoring by actigraphy is a reliable and easy method for monitoring physical activity and sleep-wake cycles after major abdominal surgery.
authors.affiliation: Department of Surgical Gastroenterology 235, Hvidovre Hospital, DK-2650 Hvidovre, Denmark. bisgaard@dadlnet.dk
authors.forename: T
authors.initials: T
authors.lastname: Bisgaard
authors.forename: M
authors.initials: M
authors.lastname: Kjaersgaard
authors.forename: A
authors.initials: A
authors.lastname: Bernhard
authors.forename: H
authors.initials: H
authors.lastname: Kehlet
authors.forename: J
authors.initials: J
authors.lastname: Rosenberg
mesh_terms: D000005:Abdomen / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory; D008991:Monitoring, Physiologic; D009043:Motor Activity; D011184:Postoperative Period; D012815:Signal Processing, Computer-Assisted; D012890:Sleep / Q000502:physiology*