TY - JOUR
T1 - Quantitative outcome measures for systemic sclerosis-related Microangiopathy – Reliability of image acquisition in Nailfold Capillaroscopy
AU - Dinsdale, Graham
AU - Moore, Tonia L
AU - O'Leary, Neil
AU - Berks, Michael
AU - Roberts, Christopher
AU - Manning, Joanne B
AU - Allen, John
AU - Anderson, Marina
AU - Cutolo, Maurizio
AU - Hesselstrand, Roger
AU - Howell, Kevin
AU - Pizzorni, Carmen
AU - Smith, Vanessa
AU - Sulli, Alberto
AU - Wildt, Marie
AU - Taylor, Christopher
AU - Murray, Andrea
AU - Herrick, Ariane L
PY - 2017/9/1
Y1 - 2017/9/1
N2 - Background Nailfold capillaroscopic parameters hold increasing promise as outcome measures for clinical trials in systemic sclerosis (SSc). Their inclusion as outcomes would often naturally require capillaroscopy images to be captured at several time points during any one study. Our objective was to assess repeatability of image acquisition (which has been little studied), as well as of measurement. Method 41 patients (26 with SSc, 15 with primary Raynaud's phenomenon) and 10 healthy controls returned for repeat high-magnification (300 ×) videocapillaroscopy mosaic imaging of 10 digits one week after initial imaging (as part of a larger study of reliability). Images were assessed in a random order by an expert blinded observer and 4 outcome measures extracted: (1) overall image grade and then (where possible) distal vessel locations were marked, allowing (2) vessel density (across the whole nailfold) to be calculated (3) apex width measurement and (4) giant vessel count. Intra-rater, intra-visit and intra-rater inter-visit (baseline vs. 1 week) reliability were examined in 475 and 392 images respectively. A linear, mixed-effects model was used to estimate variance components, from which intra-class correlation coefficients (ICCs) were determined. Results Intra-visit and inter-visit reliability estimates (ICCs) were (respectively): overall image grade, 0.97 and 0.90; vessel density, 0.92 and 0.65; mean vessel width, 0.91 and 0.79; presence of giant capillary, 0.68 and 0.56. These estimates were conditional on each parameter being measurable. Conclusion Within-operator image analysis and acquisition are reproducible. Quantitative nailfold capillaroscopy, at least with a single observer, provides reliable outcome measures for clinical studies including randomised controlled trials.
AB - Background Nailfold capillaroscopic parameters hold increasing promise as outcome measures for clinical trials in systemic sclerosis (SSc). Their inclusion as outcomes would often naturally require capillaroscopy images to be captured at several time points during any one study. Our objective was to assess repeatability of image acquisition (which has been little studied), as well as of measurement. Method 41 patients (26 with SSc, 15 with primary Raynaud's phenomenon) and 10 healthy controls returned for repeat high-magnification (300 ×) videocapillaroscopy mosaic imaging of 10 digits one week after initial imaging (as part of a larger study of reliability). Images were assessed in a random order by an expert blinded observer and 4 outcome measures extracted: (1) overall image grade and then (where possible) distal vessel locations were marked, allowing (2) vessel density (across the whole nailfold) to be calculated (3) apex width measurement and (4) giant vessel count. Intra-rater, intra-visit and intra-rater inter-visit (baseline vs. 1 week) reliability were examined in 475 and 392 images respectively. A linear, mixed-effects model was used to estimate variance components, from which intra-class correlation coefficients (ICCs) were determined. Results Intra-visit and inter-visit reliability estimates (ICCs) were (respectively): overall image grade, 0.97 and 0.90; vessel density, 0.92 and 0.65; mean vessel width, 0.91 and 0.79; presence of giant capillary, 0.68 and 0.56. These estimates were conditional on each parameter being measurable. Conclusion Within-operator image analysis and acquisition are reproducible. Quantitative nailfold capillaroscopy, at least with a single observer, provides reliable outcome measures for clinical studies including randomised controlled trials.
KW - Nailfold videocapillaroscopy
KW - Raynaud's phenomenon
KW - Reliability
KW - Systemic sclerosis
UR - http://www.scopus.com/inward/record.url?scp=85019416368&partnerID=8YFLogxK
U2 - 10.1016/j.mvr.2017.05.003
DO - 10.1016/j.mvr.2017.05.003
M3 - Article
C2 - 28495471
AN - SCOPUS:85019416368
SN - 0026-2862
VL - 113
SP - 56
EP - 59
JO - Microvascular Research
JF - Microvascular Research
ER -