title: Test-retest reliability of pulse wave velocity in individuals with chronic spinal cord injury.
abstract: BACKGROUND
  Pulse wave velocity (PWV), which reflects arterial stiffness, is an important predictor of future coronary artery disease. The test-retest reliability of PWV has not been investigated in people with spinal cord injury (SCI).
  
  
  OBJECTIVE
  To report the test-retest (day-to-day) reliability of PWV measurements among people with SCI, and to determine the smallest real difference (SRD) of PWV values.
  
  
  METHODS
  Twenty men (n = 19) and a woman (n = 1) with SCI (C4-T10; AIS A-D; ≥ 1-year post-injury; 10 with paraplegia and 10 with tetraplegia; time post-injury: 11.8 ± 8.7 years; age: 43.0 ± 12.6 years).
  
  
  METHODS
  On two occasions within a 2-week period, aortic PWV (between the common carotid and femoral artery), arm PWV (between the brachial and radial artery), and leg PWV (between femoral and posterior tibial artery) were assessed at the same time of day using Doppler flowmeters.
  
  
  RESULTS
  No statistically significant differences were found between days 1 and 2 in aortic PWV (day 1: 941 ± 185 cm/seconds, day 2: 917 ± 160 cm/seconds, P = 0.257), leg PWV (day 1: 1088 ± 141 cm/seconds, day 2: 1122 ± 165 cm/seconds, P = 0.099) and arm PWV (day 1: 1283 ± 185 cm/seconds, day 2: 1358 ± 256 cm/seconds, P = 0.180). The aortic and leg PWVs had high test-retest reliability (intraclass correlation coefficient: ICC = 0.920 and 0.913, respectively; P < 0.001 for both) and arm PWV had moderate test-retest reliability (ICC = 0.598, P = 0.03). SRDs for each PWV were 104 cm/seconds (aortic PWV), 97 cm/seconds (leg PWV) and 143 cm/seconds (arm PWV).
  
  
  CONCLUSIONS
  The test-retest reliability of PWV assessment is high among patients with chronic SCI. Changes in aortic PWV values above 104 cm/seconds with repeated testing like represent true changes in health status.
authors.affiliation: Toronto Rehabilitation Institute, Toronto, Ontario, Canada. masae.miyatani@uhn.ca
authors.forename: Masae
authors.initials: M
authors.lastname: Miyatani
authors.forename: Kei
authors.initials: K
authors.lastname: Masani
authors.forename: Cameron
authors.initials: C
authors.lastname: Moore
authors.forename: Maggie
authors.initials: M
authors.lastname: Szeto
authors.forename: Maggie
authors.initials: M
authors.lastname: Szato
authors.forename: Paul
authors.initials: P
authors.lastname: Oh
authors.forename: Catharine
authors.initials: C
authors.lastname: Craven
mesh_terms: D000328:Adult; D001011:Aorta / Q000502:physiology; D001132:Arm / Q000098:blood supply; D002908:Chronic Disease; D003324:Coronary Artery Disease / Q000150:complications* / Q000175:diagnosis* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007866:Leg / Q000098:blood supply; D008297:Male; D008875:Middle Aged; D063177:Pulse Wave Analysis / Q000379:methods* / Q000592:standards*; D015203:Reproducibility of Results; D013119:Spinal Cord Injuries / Q000150:complications*; D059289:Vascular Stiffness / Q000502:physiology