Table 4.

Symptoms and wellness scores for CFS subjects at initial classification and follow-up

Characteristic	Initial classification (N = 65)	1-year follow-up (N = 59)	2-years follow-up (N = 39)	3-years follow-up (N = 24)
CFS symptoms lasting ≥ 6 months (%)
Unrefreshing sleep	95.4	88.1	89.7	79.2*
Muscle aches or muscle pain	92.3	74.6*	74.4*	66.7*
Unusual fatigue post-exertion	78.5	50.9*	53.9*	33.3*
Difficulty thinking/concentrating or memory problems	76.9	71.2	59.0	62.5
Pain in joints	73.9	64.4	64.1	66.7
Severe headaches	58.5	35.6*	41.0	29.2*
Tender lymph nodes	16.9	20.3	12.8	4.2
Sore throat	12.3	6.8	5.3	0.0
Number of CFS symptoms (%)
0	0.0	1.7	7.7	4.2
1–3	0.0	32.2	25.6	50.0
7–8	7.7	10.2	2.6	0.0
Mean number (standard deviation)	5 (1.1)	4.1 (1.7)*	4.0 (1.7)*	3.4 (1.5)*
Non-CFS symptoms lasting ≥ 6 months (%)‡
Problems getting to sleep or waking up early in the morning	81.4	69.5	74.4	75.0
General weakness	80.0	61.0*	74.4	50.0*
Sinus or nasal problems	67.7	50.9*	53.9	58.3
Sensitivity to light	56.9	52.5	59.0	58.3
Depression	49.2	44.1	38.5	37.5
Numbness or tingling	35.9	44.8	30.8	58.3*
Shortness of breath	35.4	27.1	23.1	45.8
Stomach or abdominal pain	24.6	30.5	28.2	13.0
Diarrhea	20.0	20.3	20.5	4.2
Chills	18.8	13.6	5.1	4.2
Nausea	12.3	6.8	5.1	4.2
Fever	12.3	6.8	0.0	0.0
Mean number (standard deviation)	4.9 (2.0)	4.3 (2.2)*	4.1 (2.1)	4.1 (1.9)
Total CFS and non-CFS symptoms, mean (standard deviation)	10 (2.5)	8.4 (3.5)*	8.1 (3.5)*	7.5 (2.9)*
Wellness scores, mean (standard deviation)	41.2 (17.3)	48.5 (20.7)†	46.8 (20.5)	50.4 (17.6)

*p < 0.05 in GEE models compared with values at T0 † p < 0.05 in paired t-test ‡ Symptoms not included in CFS Case Definition