Table 2.

Distribution of covariates and outcome by intervention period and intervention group.^f

	Intervention Period
	Pre		Post
	1	2	3	4	5
Daily hours worked at office computera (mean & SD)
CWT	3.27 (0.69)	3.16 (0.78)	3.02 (0.84)	3.21 (0.76)	3.21 (0.70)
TO	3.08 (0.73)	2.98 (0.84)	2.89 (0.84)	2.82 (0.72)	2.85 (0.76)
Control	3.20 (0.80)	3.27 (0.71)	3.26 (0.68)	3.25 (0.82)	3.44 (0.72)
Chair comfortb (mean & SD)
CWT	2.52 (0.55)	2.44 (0.45)	3.13 (0.42)	3.17 (0.47)	3.12 (0.39)
TO	2.63 (0.72)	2.63 (0.70)	2.90 (0.49)	2.94 (0.41)	2.89 (0.52)
Control	2.58 (0.42)	2.50 (0.53)	2.69 (0.52)	2.75 (0.46)	2.77 (0.46)
Type of lenses wornc (%)
None
CWT	18	16	13	20	20
TO	22	21	16	14	19
Control	30	24	35	36	32
Single
CWT	39	40	40	37	30
TO	41	35	37	45	34
Control	39	38	38	38	35
Bi- or trifocal
CWT	42	44	47	43	49
TO	37	43	48	41	47
Control	31	38	27	26	33
Lighting produces glared (mean & SD)
CWT	2.61 (0.66)	2.65 (0.67)	2.80 (0.62)	2.71 (0.64)	2.71 (0.68)
TO	2.32 (0.80)	2.44 (0.76)	2.54 (0.72)	2.66 (0.56)	2.70 (0.49)
Control	2.61 (0.53)	2.59 (0.64)	2.69 (0.51)	2.55 (0.69)	2.43 (0.72)
Visual symptoms scoree (mean & SD)
CWT	2.05 (2.33)	2.03 (2.49)	1.38 (2.13)	1.37 (2.21)	1.24 (2.36)
TO	2.01 (2.16)	1.32 (1.78)	1.48 (1.79)	1.39 (2.04)	1.14 (1.66)
Control	2.71 (2.56)	2.48 (2.64)	2.37 (2.73)	2.35 (2.83)	2.65 (3.25)

^aNumber of hours worked at office computer in a typical day ranges from 0 (0 h) to 5 (>9 h).

^bChair is comfortable ranges from 1 indicating strongly disagree to 4 indicating strongly agree.

^cType of lenses worn is defined by none, single-vision, or bi/trifocal lenses.

^dLighting produces glare varies from 1 indicating strongly agree to 4 indicating strongly disagree.

^eVisual symptoms range from 0 representing no visual symptoms to 11 representing having all visual symptoms listed. Visual symptoms are averaged over the week(s) for each reporting period.

^fCWT refers to the chair-with-training group and TO refers to the training-only group.