Table 2.

Final linear mixed-effects model results summary (fixed effects), across all skill domains^a,b.

Predictors			Estimates (SE)		t test (df)		P value
Fixed effects
	Intercept	1.36×10−1 (1.18×10−2)		12.27 (2.51×101)		<.001c
	Week	9.28×10−3 (1.22×10−3)		7.62 (1.73×101)		<.001
	Dosage group (2 days per week)	1.15×10−3 (2.22×10−3)		0.52 (1.34×104)		.60
	Dosage group (3 days per week)	8.00×10−3 (2.54×10−3)		3.16 (8.21×103)		.002
	Dosage group (4 days per week)	8.30×10−3 (2.85×10−3)		2.91 (7.91×103)		.004
	Dosage group (≥5 days per week)	1.13×10−2 (2.86×10−3)		3.95 (5.09×103)		<.001
	Total hours	1.13×10−4 (3.15×10−5)		3.58 (6.05×104)		<.001
	Domain score baseline	6.62×10−1 (2.55×10−3)		259.42 (1.04×105)		<.001
	Age (years)	−1.54×10−4 (8.96×10−5)		−1.72 (1.79×103)		.09
	Sex (male)	−1.39×10−4 (2.43×10−3)		−0.06 (1.78×103)		.95
	Sex (not specified)	2.13×10−2 (1.66×10−2)		1.28 (1.83×103)		.20
	Chronicity (acute)	9.93×10−3 (2.44×10−3)		−4.07 (1.75×103)		<.001
	Week × dosage group (2 days per week)	1.13×10−3 (4.78×10−4)		2.37 (1.54×104)		.02
	Week × dosage group (3 days per week)	2.82×10−3 (5.42×10−4)		5.21 (9.74×103)		<.001
	Week × dosage group (4 days per week)	4.73×10−3 (6.05×10−4)		7.82 (9.29×103)		<.001
	Week × dosage group (≥5 days per week)	5.03×10−3 (6.17×10−4)		8.14 (6.34×103)		<.001
	Week × total hours	6.01×10−6 (4.78×10−6)		0.97 (6.50×104)		.33

^aN (total observations)=111,768; N (patients)=2249; N (domains)=13.

^bModel equation: domain score (weekly average) ~ week × (dosage group + total hours) + baseline domain score + age + sex + chronicity + (1+ week:patient) + (1+ week:domain).

^cItalicized text indicates a significant predictor, P<.001.