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

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

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)	24^a	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

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
^aIncludes 1 healthy control with time = 20 min and difficulty = 8

ISSN: 1479-5876