Methodological quality was determined by the risk of bias as-
sessment (18). Risk of bias was scored (low risk, high risk or
unclear risk) per item independently by 2 researchers (HB and
MB). Random-sequence generation, allocation concealment,
blinding of participants and personnel, blinding of outcome as-
sessment, incomplete outcome data, selective reporting, and other
biases were items that were reviewed. Judgement of blinding of
participants and personnel was considered as low risk when no
or incomplete blinding was not likely to influence the outcome,
which is expected in studies in which the work of therapists is
part of the intervention. When articles were not clear about items,
MB and HB discussed the item and decided the score. Any disa-
greements were resolved by a third researcher (JB). Scores were
processed using RevMan 5.3 (Cochrane Community.
Data extraction and synthesis
The following information was extracted from the included
articles:
Study characteristics. Population characteristics, intervention
and control setting, duration of intervention, PA outcome mea-
sure and reported significance of the effect on PA.
Intervention strategies. Wearable monitor used for feedback,
feedback parameter, frequency, visualization, therapist/coach
contact and BCT components used.
Effect size calculation. Different types of PA outcome measu-
res were allowed. Nevertheless, all measures were continuous
variables, therefore a standardized measure was used to cal-
culate effect size. The standardized mean difference (SMD)
was calculated by using the weighted inverse variance approach
for fixed-effects meta-analysis models in RevMan 5.3. SMDs
of the included studies were combined to calculate an overall
summary effect (95% confidence interval (95% CI)), SMDs of
0.2 were considered small, 0.5 moderate and 0.8 large (18). If
studies were incomplete in reporting necessary PA measures
(mean and standard deviation (SD)) for calculation of the SMD,
corresponding authors were emailed to request the missing
measures. If SDs were still missing, the calculator in RevMan
5.3 and method of Hozo et al. (19) was used to estimate missing
values. A leave-one-out sensitivity analysis was performed by
iteratively removing 1 study at a time in order to confirm that
the current results were not driven by any single study. Inconsis-
tency (heterogeneity, I 2 ) was calculated in RevMan 5.3 and was
interpreted according to the method of Higgins & Green (18). I 2
was low at 25%, moderate at 50% and high at 75%. In addition,
comparable with the method of Kang et al. (20), the contribution
of mediating effects was explored by grouping different study
characteristics if heterogeneity was significant (p < 0.05).
RESULTS
Study selection
The literature search yielded 2,322 relevant articles
after removing duplicates from the initial search
(Fig. 1). After excluding articles published before 31
December 2006 and careful screening of titles and
Methodological quality assessment
occurred, HB and MB resolved them by discussion. If no agre-
ement could be achieved, a third reviewer (JB) was consulted.
Records identified through database searhing
(n=7,293)
153
Additional records identified through other
sources (n=11)
Records after duplicates removed
(n=2,322)
Records screened
(n=1,548) Records excluded
(n=1,437)
Full-text articles assessed for
eligibility (n=64) Full-text articles excluded, with
reasons:
No RCT (n=9)
Subjects <21 years/no (former)
patients (n=15)
PA as outcome not objectively
measured (n=3)
Intervention & control difference
PA feedback (n=5)
Conference or oral sessions
abstracts (n=16)
Co-interventions combined with
other disciplines (n=2)
Studies included
(n=14)
Objective feedback on physical activity in healthcare interventions
Fig. 1. Preferred Reporting Items for Systematic Reviews and Meta-
analyses (PRISMA): flow diagram of selected studies.
abstracts for inclusion and exclusion criteria, the full
text of 64 records were checked. After consulting the
third researcher regarding 2 records, all 3 researchers
agreed that 14 studies met the inclusion criteria and
these were included in the full review. Inclusion and
exclusion was modelled using the Preferred Reporting
Items for Systematic Reviews and Meta-analyses
(PRISMA) (21) (Fig. 1).
Methodological quality
Full consensus was reached between researchers MB
and HB on risk of bias assessment. Overall, the metho-
dological quality of the included studies was moderate
to acceptable (Fig. 2). The most frequent reason for
high risk was detection (22–27) and attrition bias (22,
24, 28–30) due to lack of blinding of outcome asses-
sors and high drop-outs, or to being unclear about
incomplete outcome data. Blinding of participants and
personnel was considered low risk in any study due the
clinical intervention setting (Fig. 2). The randomiza-
tion process was not clearly described in some studies
(23, 24, 30–32). In 7 studies, the authors had reasons
to report other biases (22, 24, 27, 30–33); for 3 studies
the reason was that the RCT was a pilot RCT with a
relatively small sample size (30, 31, 33). Kaminsky et
al.’s study had the highest methodological risk (30).
Study characteristics
The studies varied with regard to the number and type
of participants, duration and intervention characte-
ristics (Table I). The total number of participants in
the included studies was 1,902, and the number of
participants per study ranged from 16 to 586. Included
populations were patients with chronic obstructive
J Rehabil Med 51, 2019