Table 1: Scales, number of items and scale formats for SF-36.

SF-36	Scale (No. of items) a	Scale format (No. of items) b	Scale score range c
Physical Component Summary Score (PCS) d	SF-36 Physical Functioning (10) e	3-point scale (10)	0–100
	SF-36 Role – Physical (4)	2-point scale (4)	0–100
	SF-36 Bodily Pain (2)	5-point scale (1), 6-point scale (1) f	0–100
	SF-36 General Health (5)	5-point scale (5)	0–100
Mental Component Summary Score (MCS) g	SF-36 Vitality (4)	6-point scale (4)	0–100
	SF-36 Social Functioning (2) g	5-point scale (2)	0–100
	SF-36 Role – Emotional (3)	2-point scale (3)	0–100
	SF-36 Mental Health (5) g	6-point scale (5)	0–100

^a Scales measuring the frequency of CHD symptoms

^b The items in the Adverse Effects scale of the CROQ-CABG and CROQ-PTCA differ as the procedures are different

^c For each instrument higher scores indicate higher functional levels

^d The Physical and Mental Component Summary Scores are scored with weights, and are expressed as t-scores with mean=50 and standard deviation=10

^e Scales measuring physical functioning

^f Items are recalibrated to the same scale format before summing to calculate the scale score

^g Scales measuring the impact of health on psychological and/or social functioning