Tab. III.

Summary of assessments of item, subscale and component score assumptions (n = 161).

	Mean	SD	Floor %	Ceiling %	Corrected item -subscale	Item - PCS-12	Item- MCS-12
Physical Health Component *	44.40	8.29	0.62	0.62	-	-	-
General Health (GH): health rating	44.72	19.85	1.86	3.73	0.40	0.63	0.31
Physical Function (PF) ^	75.93	23.37	1.86	36.65	-
Limited in moderate activities (PF1)	86.02	24.50	1.86	73.91	0.54	0.54	0.06
Limited in climbing several stairs (PF2)	65.84	29.80	6.83	38.51	0.51	0.54	0.24
Physical Role Limitation (RP) ^	63.98	41.16	23.60	51.61	-
Accomplished less due to physical health (RP1)	63.35	48.33	36.65	63.35	0.46	0.55	0.29
Limited in kind of work (RP2)	64.60	47.97	35.40	64.60	0.64	0.70	0.17
Bodily Pain (BP): Pain interferes with work	64.44	27.62	23.60	76.40	0.39&	0.62	0.17
Mental Health Component *	49.51	9.48	0.62	0.62	-
Emotional Role Limitation (RE) ^	72.67	37.89	16.14	61.49	-
Accomplished less due to emotional health (RE1)	76.40	42.60	31.06	68.94	0.38 &	0.24	0.41
Not work as carefully (RE2)	68.94	46.42	4.97	22.36	0.49	0.10	0.53
Vitality (VT): have a lot of energy (VT)	68.32	19.31	0.62	19.88	0.48	0.29	0.58
Mental Health (MH)^	68.01	20.03	0.62	8.69	-
Felt calm and peaceful (MH1)	70.43	22.03	0.62	13.66	0.68	0.26	0.74
Felt downhearted and blue (MH2)	65.59	22.27	0.62	14.29	0.52	0.32	0.67
Social Function: physical/emotional interfere with social	76.24	23.68	0.62	36.65	0.47	0.18	0.58

*: using US algorithm to create a standardised score on a 0 to 100 scale;

^: mean of the two subscale items; all other subscales are composed of one item;

Bold: highest correlation Item-PCS-12 an Item-MCS-12 are item-scale correlations (using Spearman correlation);

#: floor and ceiling % was the proportion of participant with lowest and highest responses;

^&: A correlation < 0.40 indicates that the assumption of equality of item-subscale correlations was not supported.