Early rehabilitation in CABG patients
ing CABG surgery (25), but they reported a greater
reduction in symptoms after surgery compared with
others undergoing open heart surgery (26). No trial has
investigated the effect of psycho-education combined
with physical training after CABG. A systematic review
found psycho-education intervention to have a moderate
effect in decreasing anxiety and depression after CABG
surgery (27), which is in line with our findings.
The intervention showed no effect on self-reported
physical and mental health, anxiety, pain, sleep or
health-related quality of life, but there was a positive
tendency in all outcomes. It is possible that the choice
of primary and secondary outcomes was inadequate.
The comprehensive test battery included separate
valid instruments used in other rehabilitation trials.
However, the order of the instruments could influence
the responders’ approach to the answers. Even though
the instruments were different, questions sometimes
looked similar, which could have been annoying for
some responders. It is not obvious why changes were
not found, but a plausible explanation is poor adherence
to parts of the intervention. Patient adherence was high
for the psycho-educational consultations. Subsequent
use of the mindfulness toolbox varied greatly. In most
cases the recorded mindfulness instructions were used
in a few instances for a specific problem, reflecting
mainly male participants’ scepticism towards mindful-
ness (28). The sporadic use of mindfulness tools was
expected given the brief rehabilitation programme. In
other contexts the effect of mindfulness components
requires regular practice (e.g. weekly meetings exten-
ding for 4–8 weeks after hospitalization) (29).
The per-protocol analysis showed differences bet-
ween the 2 groups in 6MWT and Sit-To-Stand test,
albeit with a small clinical effect expressed by Cohen’s
d. This suggests that non-adherence to the rehabilitation
has affected our results. The findings from the experi-
mental adherent group are identical to those of the few
studies of physical training in early rehabilitation (9,
30) and the pilot test prior to this trial (13). Hence, we
hypothesize that low adherence has biased the results
towards null. Adherence is a known challenge in reha-
bilitation (31) and was highlighted in the pilot trial (13).
Physiotherapists placed more emphasis on “why and
how to do exercise” in this trial and the self-reported
diary was simplified to enhance adherence. Further
research in adherence and in the profile of non-adherent
individuals is needed. The exploratory and hypothesis-
generating analysis could indicate from a comparative
effectiveness research point of view that the interven-
tion had an effect in those patients who had a certain
level of participation. The per-protocol analysis showed
that, for the majority of the secondary outcomes, the
experimental group had a more advantageous develop-
141
ment than the control group, resulting in a Cohen’s d
indicating a small clinical effect.
The complex intervention used here reflected the
problems associated with CABG surgery. It was
developed to be “comprehensive” and included both
physical and psycho-educational components. Howe-
ver, the programme may have been too ambitious, be-
cause when evaluating the intervention that addresses
separate components it becomes difficult to identify
the specific effect of each element. Further research is
needed to optimize the components of rehabilitation
and to identify barriers to adherence in early rehabilita-
tion after CABG.
Patients were included consecutively from an un-
selected CABG population with a number of exclu-
sion and inclusion criteria securing external validity.
The trial applied central stratified randomization to
secure against selection bias, and a blinded assess-
ment and statistical analysis to reduce detection and
interpretation bias. Of the 440 eligible patients 326
were randomized, which is a high inclusion rate in
rehabilitation. Participating in a clinical trial might
exert an effect on the physical and mental health of
patients through contact with health professionals. A
concern is that the control group might have received
unintended intervention during admission or at testing
by the trial personal. The trial results might have been
affected by the participants being aware that they were
being studied or that they received additional attention.
Self-reported outcomes as used in the diaries and the
questionnaires are by nature subjective and therefore
likely to have a risk of recall bias. Nonetheless, the
patients completed the questionnaires independently
of researchers.
In conclusion, the SheppHeartCABG had no effect
on the primary outcome, the 6MWT, or on secondary
outcomes, except that the intervention might have
had a beneficial effect on depressive symptoms. Parts
of the intervention were associated with a high level
of non-adherence, jeopardizing the “dose” received.
From the point of view of comparative effectiveness
research the intervention had a positive effect for
adherent participants, showing differences between
the 2 groups in the physical outcomes 6MWT and Sit-
To-Stand test. Furthermore, the majority of secondary
outcomes in the experimental group showed a more
advantageous development than in the control group.
However, these differences were non-significant and
had a small clinical effect.
ACKNOWLEDGEMENTS
The authors would like to thank the 326 participating patients.
We further thank the test and rehabilitation team from the
J Rehabil Med 51, 2019