Table 2.

Comparison between the postural tachycardia syndrome (PoTS) with comorbid chronic fatigue syndrome (CFS) and PoTS without comorbid CFS

		PoTS No CFS	PoTS With CFS	p Value
	N	109	27
	Proportion working n (%)	57 (52)	11 (41)	0.4
	When working hours worked (median (IQR))	30 (26–33)	5 (0.2–23)	0.001
Symptoms described by patients with PoTS	Number of symptoms first noticed (median (IQR))	2 (2.3–2.9)	1 (1.1–2.3)	0.0004
	Palpitations n (%)	80 (73)	16 (60)	0.9
	Fatigue n (%)	85 (78)	24 (89)
	Dizziness n (%)	87 (80)	20 (74)
	Memory n (%)	47 (43)	13 (48)
	Breathlessness n (%)	63 (58)	14 (52)
	Light-headedness n (%)	89 (82)	20 (74)
	Muscle aches n (%)	54 (50)	16 (59)
	Are you currently engaging in any form of exercise? n (%)	48/109 (44)	8/27 (30)	0.2
If you do not exercise, why do you not exercise? n (%)	Not interested	1/61 (2)	0/20	1.0
	No time	7/61 (12)	0/20
	Would like to but cannot because of fatigue	46/61 (75)	16/20 (80)
	Cannot because symptoms worsen	49/61 (80)	17/20 (85)
In the past 4 weeks, how many hours have you spent (median hours/week (IQR))	Household-related activities	5 (6–11)	4 (4–16)	0.5
	Social and recreational activities	4 (4–7)	4 (3–7)	0.8
	Family-related activities	5 (6–13)	5 (4–12)	1.0
	Work-related activities	3 (11–20)	0 (0.8–12)	0.04
Other symptoms (n (%))	Reports LOC or presyncope	37/109 (34)	5/27 (19)	0.2
	Symptoms consistent with CFS	47/109 (43)	20/27 (74)	0.005
Onset (n (%))	Infection	35/109 (32)	16/27 (59)	0.05
	Accident	14/109 (13)	1/27 (4)
	Holiday	7/109 (6)	1/27 (4)
	Immunisation	6/109 (6)	7/27 (26)
	Surgery	10/109 (9)	4/27 (15)
	Severe stress	24/109 (22)	8/27 (30)
	Other	34/109 (31)	5/27 (19)
	I am not ill	6/109 (6)	1/27 (4)

LOC, loss of consciousness.