title: The accuracy of assessment of walking distance in the elective spinal outpatients setting.
abstract: Self reported walking distance is a clinically relevant measure of function. The aim of this study was to define patient accuracy and understand factors that might influence perceived walking distance in an elective spinal outpatients setting. A prospective cohort study. 103 patients were asked to perform one test of distance estimation and 2 tests of functional distance perception using pre-measured landmarks. Standard spine specific outcomes included the patient reported claudication distance, Oswestry disability index (ODI), Low Back Outcome Score (LBOS), visual analogue score (VAS) for leg and back, and other measures. There are over-estimators and under-estimators. Overall, the accuracy to within 9.14 metres (m) (10 yards) was poor at only 5% for distance estimation and 40% for the two tests of functional distance perception. Distance: Actual distance 111 m; mean response 245 m (95% CI 176.3-314.7), Functional test 1 actual distance 29.2 m; mean response 71.7 m (95% CI 53.6-88.9) Functional test 2 actual distance 19.6 m; mean response 47.4 m (95% CI 35.02-59.95). Surprisingly patients over 60 years of age (n = 43) are twice as accurate with each test performed compared to those under 60 (n = 60) (average 70% overestimation compared to 140%; p = 0.06). Patients in social class I (n = 18) were more accurate than those in classes II-V (n = 85): There was a positive correlation between poor accuracy and increasing MZD (Pearson's correlation coefficient 0.250; p = 0.012). ODI, LBOS and other parameters measured showed no correlation. Subjective distance perception and estimation is poor in this population. Patients over 60 and those with a professional background are more accurate but still poor.
authors.affiliation: University Hospitals Leicester NHS Trust, Leicester General Hospital, Leicester, LE5 4PW, UK. tosanwumi@hotmail.com
authors.forename: Tosan
authors.initials: T
authors.lastname: Okoro
authors.forename: Assad
authors.initials: A
authors.lastname: Qureshi
authors.forename: Beulah
authors.initials: B
authors.lastname: Sell
authors.forename: Philip
authors.initials: P
authors.lastname: Sell
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004185:Disability Evaluation; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D020233:Gait Disorders, Neurologic / Q000175:diagnosis* / Q000209:etiology* / Q000601:surgery; D006801:Humans; D008159:Lumbar Vertebrae / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D051346:Mobility Limitation; D017063:Outcome Assessment, Health Care / Q000379:methods*; D010045:Outpatients / Q000706:statistics & numerical data; D010147:Pain Measurement; D011128:Polyradiculopathy / Q000150:complications / Q000503:physiopathology / Q000601:surgery; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012647:Self-Assessment; D012680:Sensitivity and Specificity; D013130:Spinal Stenosis / Q000150:complications* / Q000601:surgery; D016138:Walking / Q000502:physiology