Table A2.

Kaiser-Meyer-Olkin (KMO) measure of sampling adequacy.

	KMO
Physical function	0.7993
Role limitations due to physical problems	0.8600
Bodily pain	0.7399
General health perceptions	0.8944
Vitality	0.8472
Social functioning	0.9056
Role limitations due to emotional problems	0.8751
Mental health	0.7966
Overall	0.8487

Kaiser-Meyer-Olkin (KMO) takes values between 0 and 1, with small values meaning that overall the variables have too little in common to warrant a factor analysis (0.00 to 0.49 unacceptable; 0.50 to 0.59 miserable; 0.60 to 0.69 mediocre; 0.70 to 0.79 middling; 0.80 to 0.89 meritorious; 0.90 to 1.00 marvelous).