Study author | Year | Representativeness of the population | Description of outcome assessment | Adequacy of follow-up (FU) (% of losses of FU) |
Benotti et al 30 | 2017 |
YES
Patients from surgical registry matched with population-based cohort |
YES
Using International Classification of Diseases (ICD) codes from clinical information system | 0% (retrospective analysis) |
Garza et al 28 | 2010 |
YES
Patients undergoing surgery matched with controls |
NO
Abstract without clear details | 0% (retrospective analysis) |
Johnson et al 32 | 2013 |
NO
Using a population with 100% diabetes type 2 |
YES
Using administrative data | 0% (retrospective analysis) |
Karason et al 33 | 2013 |
YES
Prospective, controlled cohort study |
YES
Swedish national database searched for diagnosis | Not mentioned (abstract) |
Miranda et al 26 | 2013 |
YES
Selected patients with HF from a cohort of patients referred for surgery |
YES
Assessment through previously validated scales | 0% (retrospective analysis) |
Persson et al 34 | 2017 |
YES
Cohort created from national patient registry |
YES
Assessment using the information from the national patient registry | 0% (retrospective analysis) |
Ramani et al 18 | 2008 |
YES
Including patients from a database and matching them |
YES
Physicians performed assessments in outpatient clinic | 0% (retrospective analysis) |
Sanchis et al 35 | 2015 |
YES
Patients included who presented to the hospital for bariatric surgery |
YES
Methods for outcome assessment defined before recruitment of patients | 0% (retrospective analysis) |
Shimada et al 27 | 2016 |
NO
Self-controlled study comparing outcomes before and after surgery |
YES
Database recorded outcomes | 0% (retrospective analysis) |
Sundstrom et al 36 | 2017 |
YES
Patients included from national patient registry |
YES
Using data from patient registry | 0% (retrospective analysis) |
Vest et al 29 | 2016 |
YES
Retrospective single-institution review |
YES
Independent echocardiography readers both blinded | 0% (retrospective analysis) |
Ikramuddin et al 31 | 2015 |
MEDIUM RISK
Used random sequence allocation and allocation concealment, blinding of participants and personnel not possible |
LOW RISK
Blinded outcome assessment and no selective reporting | 7% (randomized controlled trial (RCT)) |
HF, heart failure.