Table 2.

Summary of findings using the Grading of Recommendations Assessment, Development and Evaluation approach (GRADE) for outcomes associated with number of B-lines

Outcomes	No of participants (studies)	Certainty assessment						Comments
		Risk of bias	Inconsisten-cy	Indirectness	Imprecision	Publication bias	Overall certainty of evidence
Mortality associated with no. of B-lines	837 (4 pre–post studies, 1 NRCT, 1 RCT)	Seriousa	Seriousb	Seriousc	Seriousd	None	⊗◯◯◯ Very low	The studies suggested that fewer B-lines was associated with better survival
Readmission associated with no. of B-lines	809 (4 pre–post studies, 1 NRCT)	Seriouse	Seriousb	Seriousc	Seriousf	None	⊗◯◯◯ Very low	A lower B-line count at discharge was associated with fewer readmissions
LOS associated with no. of B-lines	549 (2 pre–post studies, 2 RCTs)	Seriousg	Seriousb	Serioush	Seriousd	None	⊗◯◯◯ Very low	A fewer no. of B-lines was associated with a decreased LOS in three studies
B-lines associated with vitals	162 (1 pre–post study)	Seriousi	Not serious	Seriousj	Seriousk	None	⊗◯◯◯ Very low	B-line had a strong correlation with the respiratory rate (Spearmans coefficient 0.75)
B-lines associated with degree of dyspnea	20 (1 pre–post study)	Seriousl	Not serious	Seriousj	Seriousk	None	⊗◯◯◯ Very low	Correlation between dyspnea (on a VAS from 0 to 10) and no. of B-lines, but no correlation between the magnitude of change in sonographic pulmonary edema and VAS scores

CI confidence interval, LOS length of stay, NRCT non-randomized controlled trial, RCT randomized controlled trial, VAS visual analog scale

^aDowngraded due to risk of bias (pre–post studies: no control group, not the same treatment, no sample size calculations. RCT randomization and allocation unclear, no blinding, no sample size calculations)

^bDowngraded due to inconsistency (different scanning protocols and outcome measurements)

^cDowngraded due to indirectness (only patients with heart failure, different scanning protocols, no control groups, different outcome measurements)

^dDowngraded due to imprecision (few events and more events in control group in RCT)

^eDowngraded due to risk of bias (no control group, not provided the same treatment, outcomes not measured in a reliable way, no sample size calculations)

^fDowngraded due to imprecision (few events)

^gDowngraded due to risk of bias (pre–post studies: no control group, no sample size calculations. RCT randomization and allocation unclear, no blinding, no sample size calculations)

^hDowngraded due to indirectness (only patients with heart failure, different scanning protocols, small control group, different outcome measurements)

ⁱDowngraded due to risk of bias (no control group, no sample size calculation)

^jDowngraded due to indirectness (only patients with heart failure, no control group)

^kDowngraded due to imprecision (small sample)

^lDowngraded due to risk of bias (no control group)