Self-efficacy and outcome expectations for
exercise were assessed by the 9-item Self-Efficacy
for Exercise Scale (SEE) 37 and the 9-item
Outcome Expectations for Exercise Scale (OEE).38 The
SEE was developed to ask how confident the
participants perceive that they could exercise under
unpleasant situations. The score is rated from not
confident (0) to very confident (10). Of the OEE
items, there are five items reflect physical benefits
and four items focus on mental health benefits.
Rating score ranges from strongly agree (5) to
strongly disagree (1) for each item identified. Both
the SEE and OEE were translated and applied in a
study among Thai older persons in geriatric
rehabilitation.39 Internal consistency of the SEE and
OEE in this study, described by Cronbachûs alpha
coefficients, were .83 and .82, respectively.
Severity of knee symptoms was assessed by
the Severity of Knee Symptoms Scale-Modified
Version (M-SEV).40 This 10-item questionnaire was
used as a screening instrument and data collection
over time to assess pain, stiffness, and difficulty
with physical function related to osteoarthritis of
the knee ranged from 10 to 30. The higher score
means the higher severity. Regarding the inclusion
criteria that all eligible participants were determined
mild to moderate severity; the Cronbachûs alpha
coefficient of the M-SEV in this study was rather
low (.61).