Computerized monitoring of physical activity and sleep in postoperative abdominal surgery patients

Objective. Assessment of early postoperative activity is important in the d ocumentation of improvements of peri-operative care. This study was designe d to validate computerized activity-based monitoring of physical activity a nd sleep (actigraphy) in patients after abdominal surgery. Methods. The stu dy included twelve hospitalized patients after major abdominal surgery stud ied on day 2 to 4 after operation and twelve unhospitalized healthy volunte ers. Measurements were performed for 24 consecutive hours. The actigraphy m easurements were compared with self-reported activity- and sleep registrati on. The actigraphy output was obtained by the zero-crossing mode (ZCM) and time-above-threshold mode (TATM). Results. The overall results showed compa rable mean agreement between actigraphy and self-reported activity registra tions for patients of 80% (SD 12%) and volunteers of 84% (SD 6%) (p = 0.15) . In both study groups, all correlation coefficients between actigraphy mea surements and self-reported activity data were statistically signicant (r(s ) 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 sl eep registration were found in the volunteers (85%, SD 15%) compared with t he patients (77%, SD 11%) (p < 0.05). The mean activity value awake was hig her in the volunteers than in the patients (p < 0.05). Conclusion. Computer ized activity monitoring by actigraphy is a reliable and easy method for mo nitoring physical activity and sleep-wake cycles after major abdominal surg ery.