Measures
QOL
In Andersen’s behavioral model, outcomes include perceived
health and satisfaction [9]. We expanded these
outcomes to the broader concept QOL. Participants’ QOL
was measured using 3 variables: HQOL, social functioning,
and emotional well-being. The HQOL score was a composite
of the number of physically and mentally unhealthy
days in the past month. In two NHANES questions, participants
were asked how many days during the past
30 days their physical health was not good and how many
days their mental health was not good. These single items
and the composite score have been validated in test–retests
and against reported health conditions, physical exams, and
broader instruments such as the SF-36 and the WHOQoLBREF
[27, 28]. The distribution of HQOL clearly showed
two modes with 56.6% of the sample reporting no days of
physical or mental unhealth and 12% reporting 30
unhealthy days. In order to improve the data with respect to
the shape of the distribution, a revised HQOL variable was
created with 6 levels: no unhealthy days = 0, one to
five = 1, six to ten = 2, eleven to fifteen = 3, sixteen to
twenty-nine = 4, and thirty = 5.