Table 2.

Risk of bias judgments for chronic obstructive pulmonary disease and asthma randomized controlled trials.

COPDa or asthma study			Bias arising from the randomization process		Bias due to deviations from the intended intervention		Bias due to missing outcome data		Bias in measurement of the outcome		Bias in selection of the reported result		Overall bias
COPD
	Bentley et al [45]	Lb		Sc		L		S		S		Hd
	Cameron et al [46]	L		S		L		S		L		S
	Casas et al [47]	L		S		S		L		L		S
	Chau et al [48]	S		H		L		S		L		H
	Garcia [22]	L		S		L		S		L		S
	Haesum et al [49]	L		S		L		S		L		S
	Jehn et al [50]	S		H		L		S		L		H
	Koff et al [24]	L		H		L		S		L		H
	Nguyen et al [51]	L		S		L		S		S		H
	Sorknaes et al [52]	L		S		L		L		L		S
	Stamenova et al [53]	L		S		L		S		L		S
	Wang et al [54]	L		S		L		S		L		S
	Wang et al [55]	L		S		L		S		L		S
	Wei et al [56]	L		S		L		S		L		S
	Xin et al [57]	L		S		L		S		L		S
Asthma
	Barbanel et al [23]	L		S		L		S		L		S
	Cao et al [58]	S		S		S		S		L		H
	Kohler et al [59]	S		S		L		S		L		H
	Ostojic et al [60]	S		S		L		S		L		H
	Türk et al [61]	L		S		L		S		L		S
	van der Meer et al [25]	L		S		L		S		L		S
	van Gaalen et al [62]	L		S		L		S		L		S

^aCOPD: chronic obstructive pulmonary disease.

^bL: low risk of bias.

^cS: some concerns.

^dH: high risk of bias.