Assessing sleep disturbance in low back pain: the validity of portable instruments.
Although portable instruments have been used in the assessment of sleep disturbance for patients with low back pain (LBP), the accuracy of the instruments in detecting sleep/wake episodes for this population is unknown. This study investigated the criterion validity of two portable instruments (Armband and Actiwatch) for assessing sleep disturbance in patients with LBP. 50 patients with LBP performed simultaneous overnight sleep recordings in a university sleep laboratory. All 50 participants were assessed by Polysomnography (PSG) and the Armband and a subgroup of 33 participants wore an Actiwatch. Criterion validity was determined by calculating epoch-by-epoch agreement, sensitivity, specificity and prevalence and bias- adjusted kappa (PABAK) for sleep versus wake between each instrument and PSG. The relationship between PSG and the two instruments was assessed using intraclass correlation coefficients (ICC 2, 1). The study participants showed symptoms of sub-threshold insomnia (mean ISI = 13.2, 95% CI = 6.36) and poor sleep quality (mean PSQI = 9.20, 95% CI = 4.27). Observed agreement with PSG was 85% and 88% for the Armband and Actiwatch. Sensitivity was 0.90 for both instruments and specificity was 0.54 and 0.67 and PABAK of 0.69 and 0.77 for the Armband and Actiwatch respectively. The ICC (95%CI) was 0.76 (0.61 to 0.86) and 0.80 (0.46 to 0.92) for total sleep time, 0.52 (0.29 to 0.70) and 0.55 (0.14 to 0.77) for sleep efficiency, 0.64 (0.45 to 0.78) and 0.52 (0.23 to 0.73) for wake after sleep onset and 0.13 (-0.15 to 0.39) and 0.33 (-0.05 to 0.63) for sleep onset latency, for the Armband and Actiwatch, respectively. The findings showed that both instruments have varied criterion validity across the sleep parameters from excellent validity for measures of total sleep time, good validity for measures of sleep efficiency and wake after onset to poor validity for sleep onset latency.
Department of physiotherapy, King Fahd Hospital of the University, The University of Dammam, Khobar, Saudi Arabia.
Saad M
SM
Alsaadi
The George Institute for Global Health, Faculty of Medicine, The University of Sydney, Sydney, Australia.
James H
JH
McAuley
Department of Health Professions, Faculty of Human Sciences, Australian School of Advanced Medicine, Macquarie University, Sydney, Australia.
Julia M
JM
Hush
The Woolcock Institute of Medical Research, The University of Sydney, Sydney, Australia.
Delwyn J
DJ
Bartlett
Clinical and Rehabilitation Sciences, The University of Sydney, Sydney, New South Wales, Australia.
Zoe M
ZM
McKeough
The Woolcock Institute of Medical Research, The University of Sydney, Sydney, Australia; Department of Respiratory and Sleep Medicine, Royal Prince Alfred Hospital, Sydney, Australia.
Ronald R
RR
Grunstein
The Woolcock Institute of Medical Research, The University of Sydney, Sydney, Australia.
George C
GC
Dungan
The George Institute for Global Health, Faculty of Medicine, The University of Sydney, Sydney, Australia.
Chris G
CG
Maher
D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000150:complications*; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000295:instrumentation* / Q000379:methods; D012680:Sensitivity and Specificity; D012893:Sleep Wake Disorders / Q000175:diagnosis* / Q000209:etiology; D012984:Software