Hamano 2001.

Study characteristics
Methods	Prospective, randomised study Run‐in period: from April 1997 to December 1998 Study date: 2001 Number of study centres and locations: not specified
Participants	Forty‐eight adult patients were included in this study, 27 of whom underwent conventional surgery and 21 MICS. Mean age: 62.25 years Sex (female/male ratio): 41.67% No high‐risk patients Inclusion criteria: patients who underwent surgery for single valve disease Exclusion criteria: not specified
Interventions	Intervention group: minimally invasive cardiac surgery (a small skin incision) Control group: conventional cardiac surgery
Outcomes	Duration and degree of SIRS, the level of CRP, the operating times, perfusion times or aorta clamp times, mean volume of blood transfusion, infection or organ failure Blood samples were collected 1 day, 3 days, and 6 days postoperatively.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No clear randomisation method description is given; however, the two groups had similar baseline characteristics: "of the 48 patients, 21 were randomly selected to undergo MICS".
Allocation concealment (selection bias)	Unclear risk	No allocation concealment information
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not specified; unfeasible because of the type of intervention; unclear whether it influenced management in the postoperative period and outcomes
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not specified
Incomplete outcome data (attrition bias) All outcomes	Low risk	No trial group changes, no withdrawals, and no losses to follow‐up were reported, but no ITT analysis. Data from all the participants were included in the final analysis.
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported properly.
Other bias	Low risk	No funding was disclosed.