Summarizing health-related quality of life (HRQOL): development and testing of a one-factor model

Table 1 Correlation matrix and internal consistency of the CDC HRQOL-4 items, BRFSS 2013

	General health status	Physically unhealthy days	Mentally unhealthy days	Activity limitation days	Cronbach's alpha if item removed	Change (%)
General health status^a	1				0.733	-3.9
Physically unhealthy days^b	0.52	1			0.651	-14.6
Mentally unhealthy days^c	0.29	0.35	1		0.773	+1.3
Activity limitation days^d	0.43	0.65	0.44	1	0.656	-14
Overall construct					0.763

^aWould you say that in general your health is excellent, very good, good, fair, or poor?
^bNow thinking about your physical health, which includes physical illness and injury, for how many days during the past 30 days was your physical health not good?
^cNow thinking about your mental health, which includes stress, depression, and problems with emotions, for how many days during the past 30 days was your mental health not good?
^dDuring the past 30 days, for about how many days did poor physical or mental health keep you from doing your usual activities, such as self-care, work, or recreation?

ISSN: 1478-7954