Updates in breathomics behavior in ischemic heart disease and heart failure, mass-spectrometry

Table 1 Quality assessment “risk of bias” for the selected studies based on the method proposed by Cochran

Bias domain	Low risk	High risk	Unclear risk
Selection bias	Random sequence generation and allocation concealment both well described	Random sequence generation or allocation concealment not well described or inappropriate method used	Random sequence generation or allocation concealment not reported
Performance bias	Blinding of participants and personnel, and the outcome is not likely to be influenced by lack of blinding	Blinding of participants and personnel, and the outcome is likely to be influenced by lack of blinding	Blinding of participants and personnel not reported
Detection bias	Blinding of outcome assessment, and the outcome measurement is not likely to be influenced by lack of blinding	Blinding of outcome assessment, and the outcome measurement is likely to be influenced by lack of blinding	Blinding of outcome assessment not reported
Attrition bias	No missing outcome data or reason for missing data unlikely to be related to true outcome	Missing outcome data likely to be related to true outcome	Incomplete outcome data reported, and the reason for missing data not described
Reporting bias	The study protocol is available, and all of the study's pre-specified (primary and secondary) outcomes that are of interest in the review have been reported in the pre-specified way	One or more reported primary outcomes were not pre-specified (or, if they were, they were measured differently), or the reporting of primary outcomes is incomplete and not according to the protocol	No study protocol is available, and it is unclear whether the reported outcomes were pre-specified or not
Other bias	The study appears to be free of other sources of bias	The study has at least one important risk of bias	There is insufficient information to assess whether an important risk of bias exists