Skip to main content

Table 3 Definitions of weighted standing time (WST minutes) healthy study controls and ME/CFS classes

From: Weighting of orthostatic intolerance time measurements with standing difficulty score stratifies ME/CFS symptom severity and analyte detection

Class n WST (mins) Definition of category
No ME/CFS (0) 16 15.0–20.0 Did not meet the Canadian Criteria. All stood 20 min with difficulty ranging from 0 to 3
Mild (1) 8 15.0–20.0 Met the Canadian criteria. All stood 20 min with difficulty ranging from 0 to 3
Moderate (2) 24a 6.0–< 15.0 Met the Canadian criteria. All stood 20 min with difficulty ranging from 4 to 10
Severe (3) 14 < 6.0 Met the Canadian criteria. All stood < 20 min with difficulty assigned as 12 or 14
  1. Severe case standing difficulty scored as 12 if the CFS/ME participant stood for 10–18 min, and 14 if standing upright was possible for less than (<) 10 min
  2. aIncludes 1 healthy control with time = 20 min and difficulty = 8