Validation of an activity monitor during sleep in patients with chronic respiratory

SummaryIntroduction: Objective of this study was to validate an activity monitor (DynaPort MoveMoni-tor [MM], McRoberts, The Hague, The Netherlands) against night-vision video analysis duringsleep.Methods: Twenty patients (65 211 years old, mean body-mass-index: 27 6kg/m)withdifferent chronic lung diseases were recruited to participate in this validation study. Patientsperformed a polysomnography measurement during one single night while wearing the MM. Theactivity monitor data of the MM were then validated against the analysis of the night-visionvideo by an independent investigator. In total, four different lying positions (supine, left, rightand prone), sitting upright, out of bed as well as large, medium, small and sitting transitionswere classified.Results: A mean duration of 7.6 0.9 h per night of video and MM classification was availablefor analysis. In total, 702 different postures were registered on the video from which 678 pos-tures (96.6%) were detected correctly by the MM compared to the video classification. Theseresults yielded a total degree of sensitivity of 93.9% and specificity 94.9% in detecting posturesduring the night. In total, 682 transitions (394 small, 189 medium, 15 large and 84 sitting tran-sitions) were detected of which 482 were also detected by the MM. The MM detected 70% of theAbbreviationlist: COPD, chronic obstructive pulmonary disease; MM, MoveMonitor; NPV, negative predictive values; OOB, out of bed; PPV,positive predictive values.* Corresponding author. Schoen Klinik Berchtesgadener Land, Department of Respiratory Medicine & Pulmonary Rehabilitation, 83471Schoenau am Koenigssee, Germany. Tel.: þ49 (0) 8652 931630; fax: þ49 (0) 8652 931831.E-mail address: rgloeckl@schoen-kliniken.de (R. Gloeckl).