APPENDIX 1: Risk of bias analysis for randomized control studies
Bias
Authors'
Support for judgment
judgment
Pokushalov study
Random sequence
Low Risk
generation (selection bias)
Allocation concealment
Randomized with a coded
envelope system
Low Risk
Coded envelope system
Low Risk
Double blind with patient and
(selection bias)
Blinding of participants
and personnel
clinician responsible for follow-
(performance bias)
up of AF and blood pressure
unaware of renal denervation
occurred
Blinding of outcome
Low Risk
Double blind with patient and
assessment (detection
clinician responsible for follow-
bias)
up of AF and blood pressure
unaware of renal denervation
occurred
Incomplete outcome data
Low Risk
No patients lost to follow-up
Low Risk
Report on all primary and
(attrition bias)
Selective reporting
(reporting bias)
Other bias
secondary outcomes
Low Risk
No other sources of bias
identified
Symplicity HTN-2
Random sequence
Unclear risk
generation (selection bias)
Patients were randomly
assigned...in a one-to-one ratio.
Comment: No explanation of the
generation of the randomization
Allocation concealment
Low risk
Sealed envelopes used at all sites
High risk
Patients would know they had the
(selection bias)
Blinding of participants
and personnel
procedure as no sham procedure
(performance bias)
done
Blinding of outcome
High risk
assessment (detection
Data analyzers were not masked
to treatment group assignment
bias)
Incomplete outcome data
Low risk
(attrition bias)
Only 3 patients did not attend the
6 month follow-up appointment
either for withdrawing consent or
missing a visit
Selective reporting
Low risk
(reporting bias)
All predefined primary and
secondary outcomes were
reported
Other bias
High risk
The sponsor had full access to all
the data including how it was
collected and analyzed
APPENDIX 2: Bias assessment of Cohort and Uncontrolled* Studies
Study
Selection Comparability Outcome
Ahmed et al. 2012
☆☆☆
☆☆☆
Hering et al. 2012
☆☆☆
☆☆
Kaltenbach et al. 2012
☆☆☆
☆☆☆
Krum et al. 2009
☆☆☆
Mabin et al. 2012
☆☆☆
☆☆
Prochnau et al. 2012
☆☆☆
☆☆
Symplicity HTN-1 2011
☆☆☆
☆☆
Ukena et al. 2012
☆☆☆
☆☆
Witkowski et al. 2011
☆☆☆
☆☆☆
Zuern et al. 2012
☆☆☆
☆☆☆
☆☆
☆☆
In the Newcastle-Ottawa scale studies are assigned up to 4 stars for selection, 2 for comparability
and 3 for outcome.
* For uncontrolled studies the maximum available stars in the Newcastle-Ottawa scale is 3 for
selection, 0 for Comparability, and 3 for Outcome.
NEWCASTLE - OTTAWA QUALITY ASSESSMENT SCALE COHORT STUDIES
Note: A study can be awarded a maximum of one star for each numbered item within the
Selection and Outcome categories. A maximum of two stars can be given for Comparability
Selection
1) Representativeness of the exposed cohort
a) truly representative of the average _______________ (describe) in the community ☆
b) somewhat representative of the average ______________ in the community ☆
c) selected group of users, e.g., nurses, volunteers
d) no description of the derivation of the cohort
2) Selection of the nonexposed cohort
a) drawn from the same community as the exposed cohort ☆
b) drawn from a different source
c) no description of the derivation of the nonexposed cohort
3) Ascertainment of exposure
a) secure record (e.g., surgical records) ☆
b) structured interview ☆
c) written self-report
d) no description
4) Demonstration that outcome of interest was not present at start of study
a) yes ☆
b) no
Comparability
1) Comparability of cohorts on the basis of the design or analysis
a) study controls for _____________ (select the most important factor) ☆
b) study controls for any additional factor ☆ (This criteria could be modified to indicate specific
control for a second important factor.)
Outcome
1) Assessment of outcome
a) independent blind assessment ☆
b) record linkage ☆
c) self-report
d) no description
2) Was follow-up long enough for outcomes to occur
a) yes (select an adequate follow up period for outcome of interest) ☆
b) no
3) Adequacy of follow up of cohorts
a) complete follow up - all subjects accounted for ☆
b) subjects lost to follow up unlikely to introduce bias - small number lost - > ____ % (select an
adequate %) follow up, or description provided of those lost) ☆
c) follow-up rate < ____% (select an adequate %) and no description of those lost
d) no statement