Table 4.

Summary of quality of evidence using the GRADE approach.

Quality assessment								Effect	Quality of evidence—GRADE
Outcome	Study design	No. of studies (no. of participants)	Risk of bias	Inconsistency	Indirectness	Imprecision	Other considerations	Rw (95 % CI)
Positive effect on AP where staff with higher professional qualifications performed intervention	15 randomized, 7 non-randomized	22 (6,536)	No serious risk of bias (15 low risk of bias, 4 moderate risk of bias).	No serious inconsistency I2 = 97.8%	No serious indirectness.	No serious limitations.	None	0.22 (0.07–0.37)	⊕⊕⊕□ MODERATE (6 high, 13 moderate, 3 low)
Positive effect on AP where staff with lower professional qualifications performed intervention	15 randomized, 7 non-randomized	22 (7,145)	No serious risk of bias (2 moderate risk of bias, 5 high risk of bias).	No serious inconsistency I2 = 96.6%	No serious indirectness.	No serious limitations.	None	0.14 (0.02–0.27)	⊕⊕⊕□ MODERATE (4 high, 14 moderate, 4 low)

GRADE, Grades of Research, Assessment, Development and Evaluation (GRADE Working Group).

⊕⊕⊕⊕ (high): We have a lot of confidence that the true effect is similar to the estimated effect.

⊕⊕⊕□ (moderate): We believe that the true effect is probably close to the estimated effect.

⊕⊕□□ (low): We believe that the true effect might be markedly different from the estimated effect

⊕□□□ (very low): We believe that the true effect is probably markedly different from the estimated effect.