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(SD 21.5). With a level of significance of 0.05, a power of 0.8
and a difference between groups of 17 (corresponding to, for
example, means 39 and 22), the necessary number of patients
in each randomization arm is n = 26. No power calculation was
made in relation to the other questionnaires. Baseline characteristics of participants are listed in
Table I.
Maximum exercise capacity. Hegbom et al., in 2006 (7), com-
pared changes in maximum exercise capacity between 2 groups
of patients with AF, of which only one group received active
exercise therapy. From this paper, mean and SD of changes in
measure of maximum exercise capacity (CW max) are stated as
0.3 and 0.26 (W × min), respectively. With a level of significance
of 0.05, a power of 0.8 and a difference between groups of 0.3
(corresponding to, for example, means before/after of 1.3/1.6
for the active group and 1.3/1.3 for the passive group), the ne-
cessary number of patients in each randomization arm is n = 16.
The differences in time course in mean outcome values bet-
ween the 2 randomization groups at baseline and at 3, 6 and 12
months were analysed by repeated measures ANOVA, taking
into account the within-patient correlation. All hypotheses were
specified a priori, thus, no corrections for multiple testing were
made (18). Assumptions of normality and variance homogen-
eity were assessed by residual plots. Sensitivity analyses were
performed using robust variance estimation to manage potential
variance heterogeneity, using log-transformed data to accom-
modate right skewness and using bootstrap when assumptions
in general were not met. Stata statistical software (version
13; StataCorp LP, College Station, TX, USA) was used for
randomization and analyses. Two-tailed p-values <0.05 were
considered statistically significant. For all QoL questionnaires, the trend was an increase
in QoL from the baseline to 6 months questionnaire,
which was higher in the intervention group than in
the control group, although not all differences were
statistically significant.
Using the AF-QoL-18 questionnaire, we found
that the intervention group had a significantly higher
increase in score during the first 6 months, but only
a minor not statistically significant difference at 12
months (Table II and Fig. 2a). When separating the AF-
QoL-18 into the 3 domains (physical, psychological
and sexual activity), we found the same trend in all 3
sub-analyses, with the most pronounced effect in the
physical domain (data not shown).
Results from the AFEQT questionnaire were similar
(Table II and Fig. 2b).
Ethical issues
All patients received oral and written information, emphasizing
that participating in the study was voluntary and withdrawing
their informed consent at any time would not affect the present
or future treatment. The project was approved by the local ethics
committee (approval number N-20120002) and conducted in
conformity with the Declaration of Helsinki.
Data were collected according to the principles of good
clinical practice and the project was reported to the Danish Data
Protection Agency (2008-58-0028).
RESULTS
A total of 823 patients were screened. The majority
of patients did not meet the inclusion criteria (Fig. 1).
The low inclusion rate (7%) was explained mainly by
exclusion of patients who were eligible for other reha-
bilitation programmes or experienced comorbidities.
Consequently, 90 patients eligible for inclusion were
invited to participate in the study, of whom 58 (64%)
accepted the invitation. Barriers to participation were
mostly time-consumption or not being able to partici-
pate due to the patients’ work.
Two patients from the rehabilitation group and 4
from the control group did not return the questionnaires
and were lost to follow-up. Over 80% of the interven-
tion group participated in ≥ 75% of the rehabilitation
programme.
www.medicaljournals.se/jrm
Questionnaires
823 patients screened
for the study
268 patients had
coronary heart disease
or congestive heart
faliure
111 patients received
RFA
43 patients dropped off
for temporary causes 52 patients had
permanent AF
235 patients deemed to
be too ill 24 patients were
excluded for other
reasons
90 patients invited to
participate
58 patients included
28 patients in control
group
30 patients in
intervention group
Fig. 1. Fig. 1. Flowchart of participants. RFA: radio frequency ablation,
AF: atrial fibrillation.