2010 review - Patient-Reported Outcomes Measurement - University ...

The DASI correlates strongly with the ‘gold standard’ for functional capacity in cardiac
disease, namely, maximal oxygen uptake during exercise testing, and therefore has criterion
validity (Hlatky et al., 1989).
Discriminative validity of the DASI was reported in a study of patients undergoing cardiac
catheterisation prior to coronary revascularisation (Nelson et al., 1991). Significant
correlations were found between DASI scores and demographic factors (age, sex), and
between DASI scores and severity of cardiac disease (three-vessel disease, history of MI or
heart failure) (Nelson et al., 1991).
Construct validity of the DASI was supported in the Study of Economics and Quality of Life
ancillary to the BARI trial (BARI-SEQOL) by significant correlations with angina symptoms
(Bourassa et al., 2000), and with TTO scores (Melsop et al., 2003).
The DASI discriminated between treatment groups in a major study comparing the outcomes
of coronary angioplasty versus bypass surgery, with significantly greater improvement in the
CABG group (Hlatky et al., 1997; BARI trial). Improvement in DASI scores also differed
significantly in those with HF compared to those without HF, in diabetics versus nondiabetics,
in men versus women, and in older versus younger patients (Hlatky et al., 1997).
However, the difference between treatment groups narrowed over time, and was no longer
significant at four years (Hlatky et al., 2004; BARI trial).
DASI scores showed significant differences between treatment groups at four months in
another large study comparing PCI and medical treatment (Mark et al., 2009a; OAT trial),
though the difference was not sustained over time. DASI scores also discriminated between
patients with and without prior symptoms (Pilote et al., 1995), and between Canadian and US
patients in the SEQOL substudy (Pilote et al., 1995; Bourassa et al., 2000). The latter finding
appears to reflect different patterns of care in the two countries.
The DASI has been used in a number of studies investigating gender differences in the
experience of cardiac surgery. The measure appears to discriminate between men and
women, as illustrated in a study of patients undergoing CABG where women’s scores on the
DASI were significantly lower at baseline and six months than men’s, although the degree of
change in score was comparable (Stewart et al., 1999). Women had significantly lower DASI
scores at baseline in a study examining the effect of gender on early recovery from CABG
and/or valve surgery (King, 2000). At three months post-procedure, this difference was no
longer significant; however, women experienced a significantly greater degree of
improvement (King, 2000). DASI scores showed significantly poorer outcomes for women at
one year post-CABG, independent of pre-existing risk factors (Phillips-Bute et al., 2003).
Women undergoing CABG had significantly poorer HRQoL than men as reflected in DASI
score, at baseline and follow-up, independent of age, co-morbidity, and post-operative
sequelae (Koch et al., 2004). Significant differences in DASI scores between men and women
undergoing CABG were found at three time-points in a study by Sawatzky & Naimark
(2009b).
Predictive validity of the DASI was reported in two studies. DASI scores taken during the
recovery period (at six and 12 months) after CABG and/or valve surgery predicted long-term
survival (median follow-up 8.6 years) (Koch et al., 2007). Baseline DASI score predicted
early readmission post-discharge in a study of risk and outcomes with a CABG sample
(Sawatzky & Naimark, 2009a).
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