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consultation guide was followed to ensure intervention fidelity
and the nurses were supervised regularly (13). The psycho-
educative intervention consisted of 4 face-to-face consultations.
Mindfulness was an integral element in the psycho-educational
consultation and was provided as a toolbox of recorded medi-
tation instructions for personal use, e.g. as an alternative to
medication for sleep disorders and physically and emotionally
stressful situations (14). of achieving an improvement in 6MWT by 30 m, a standard
deviation of 90 m, with alpha of 5% and a power of 85%. The
anticipated improvement in the intervention group is assumed
to be feasible because the SheppHeartCABG pilot (13) showed
a mean of 548 m in the intervention group and 451 m in the
control group measured by 6MWT.
Control group Intention-to-treat analyses were used. There were 2 types of
comparisons between the intervention groups: (i) comparison
of values at week 4 after surgery, this analysis used a general
univariate linear model (excepting HeartQol and HADS (see
below) adjusted for baseline values and stratifying variables
(sex and site)) and (ii) comparison of values at discharge and
at 4 weeks. This analysis used a mixed linear model including
an unstructured covariance matrix. In this model, the interac-
tion between intervention and time was of principal interest.
This analysis was adjusted for baseline values and stratifying
variables (sex and site). If the assumptions of the models were
not fulfilled with reasonable approximation, removal of outli-
ers and transformation of outcome were performed. HeartQol
quantities were converted to binary quantities based on the
median score among available cases. HADS was reported as
mean and standard deviation and converted to binary quantities
(score ≥ 8) as probable anxiety or depression. For both outcomes,
logistic regression models were used to compare the experi-
mental and control group (usual care) at 4 weeks, adjusted for
value at baseline. Since almost all secondary outcomes were
overpowered (14), Cohen’s d was calculated for primary and
secondary outcomes as a measure of effect size.
For the primary and secondary outcomes, multiple imputa-
tion of missing values using the Markov chain Monte Carlo
approach was carried out, since the number of participants with
missing values was above 5%. The variables included group,
stratifying variables (site and sex), time (baseline, discharge
and 4 weeks after discharge) and all outcomes. The primary
outcome (6MWT) was tested using a significance level of 0.05.
Analyses of the secondary outcome measures as pre-planned
All patients in the control group followed usual care procedures
(16), which included medical follow-up and standard treatment
according to disease-specific guidelines (2). Admission time after
CABG is between 5 and 8 days. Usual care includes preoperative
and postoperative information provided by physicians, nurses and
physiotherapist. Instructions regarding precautions after sterno-
tomy are pre-operatively supplied by physiotherapists covering
the immediate postoperative period during hospitalization. Close
to discharge the physiotherapists introduced and informed the
patients about how to be physically active, but still pretecting the
sternum.The main topics of preoperative nursing are: an admis-
sion interview, followed by postoperative screening (falls, nutri-
tion); introduction to postoperative pain and nausea medications;
pain assessment and postoperative activities. Initial postoperative
care focuses on observation of vital signs. The subsequent time
in hospital focuses on recovery and preparation for discharge.
Outcome assessment was carried out at 3 time-points: baseline;
discharge; and 4 weeks post-CABG.
Primary outcome: physical function. Physical functioning at
4 weeks following CABG was measured with the Six Minute
Walk Test (6MWT) (17). Participants walked up and down a
30-m hallway for 6 min according to guidelines (18).
Safety considerations
The 6MWT was administered by a nurse
or a physiotherapist at baseline and by phy-
siotherapists at discharge and 4 weeks after
surgery, with defined criteria for termination
(18). Serious adverse events were registered
and discussed with the responsible physician
and primary investigator.
Sample size
Sample size was calculated to comprise
326 participants based on the expectation
www.medicaljournals.se/jrm
Asessed for eligibility, n=717
Excluded, n=277
• Cardio-vascular status, n=7
• Neurologic or orthopaedic diseases, n=130
• Non-Danish speakers, n=34
• No permanent Danish adress, n=16
• No possibility for follow-up, n=16
• Participation in other trials, v=80
Secondary outcomes. The secondary outcomes were physical
activity and mental health measured by the Medical Outcome
Study Short Form (SF-12) (19), anxiety and
depression by the Hospital Anxiety and De-
pression Scale (HADS) questionnaire (20),
physical, emotional and global scores by the
HeartQoL questionnaire (21), sleep expressed
by the Pittsburgh Sleep Quality Index (PSQI)
(22), pain evaluated by the Örebro Muscu-
loskeletal Screening Questionnaire (ÖMSQ)
(23), and muscle endurance measured by a
Asessed for eligibility, n=440
Sit-To-Stand test (24).
•
•
•
•
Eiligible non-participants, n=114
Did not wish to participate, n=55
Not able to cope, n=47
Other reasons not stated, n=12
Randomized, n=326
Allocated to intervention, n=163
Outcomes
Statistical analysis
Allocated to control group, n=163
Dropout*, n=11 Dropout*, n=5
Dropout**, n=12 Dropout**, n=4
Completed 4 weeks 6MWT, n=111
Completed 4 weeks 6MWT, n=103
*Dropout: dropped out and wanted to extract their data from the trial
**Dropout: dropped out from the trial with acceptance to use data.
Fig. 2. Flow of patients in the SheppHeartCABG trial. Consolidated Standard of Reporting
Trials (CONSORT) flow diagram.