Efficacy of electro-acupuncture and manual acupuncture versus sham acupuncture for knee osteoarthritis: statistical analysis plan for a randomized controlled trial

Table 1 Baseline characteristics

Baseline characteristic	Type	Levels or scale
Gender	Categorical	Male or female
Age	Continuous	Years
Nationality	Categorical	Han or other
Duration of disease	Continuous	Years
Kellgren–Lawrence grade	Categorical	Grade II or III
Body mass index	Continuous	kg/m²
Years of education	Categorical	<9, 9–12, or >12
Affected knee	Categorical	Unilateral or bilateral
Previous treatments	Categorical	Injections, medication, physical therapy, acupuncture, exercise, etc.
Concomitant diseases	Categorical	Hypertension, coronary heart disease, diabetes mellitus, hyperlipidemia, etc.
Numerical rating scale	Continuous	Point
WOMAC pain subscale	Continuous	Point
WOMAC function subscale	Continuous	Point
WOMAC stiffness subscale	Continuous	Point
Physical health, SF-12	Continuous	Point
Mental health, SF-12	Continuous	Point

WOMAC Western Ontario and McMaster Universities osteoarthritis index, SF-12 12-item Short Form Health Survey

ISSN: 1745-6215