Table 4.

Assessment of Risk of Bias in Nonrandomized Studies Using the ROBINS-I Tool.¹¹

Study	Bias Due to Confounding	Bias in Selection of Participants Into the Study	Bias in Classification of Interventions	Bias Due to Deviations From Intended Interventions	Bias Due to Missing Data	Bias in Measurement of Outcomes	Bias in Selection of the Reported Result
Kennedy et al12	Critical	Low	Moderate	Low	Low	Serious	Moderate
Pergolizzi et al30	Moderate	Low	Low	Low	Low	Low	Low
Dobscha et al41	Low	Low	Low	Low	Low	Serious	Low
Fain et al13	No information	Low	Moderate	Low	No information	Low	Low
Fain et al14	Moderate	Low	Low	Low	Low	Serious	Low
Guerriero et al15	Moderate	Low	Low	Low	Low	Serious	Low
Krebs et al42	Serious	Serious	Low	Low	Low	Moderate	Low
Kuo et al43	No information	Low	Low	Moderate	Low	Moderate	Moderate
Lazzari et al31	Serious	Low	Serious	Low	Low	Serious	Serious
Lee et al16	No information	Low	Serious	Low	Serious	Serious	Low
Turner et al17	Serious	Low	Low	Low	Low	Moderate	Low
Petro et al18	Serious	Low	Moderate	Low	Low	Serious	Low
Dublin et al19	Serious	Low	Low	Low	Low	Low	Moderate
Lee et al32	Critical	Low	Low	Low	Low	Low	No information
Veal et al33	Critical	Low	Serious	No information	Low	Low	No information
Enthoven et al20	Serious	Low	Low	Low	Low	Serious	Moderate
Prunuske et al44	No information	Moderate	Low	Low	Low	Low	Low
Koponen et al45	Critical	Low	Serious	No information	Moderate	Serious	Moderate
Ringe et al21	No information	Low	Moderate	No information	Low	Low	Moderate
Uberall et al22	No information	Low	Moderate	Low	Low	Serious	Moderate
Gianni et al23	Serious	Low	Serious	Low	No information	Serious	Moderate
Gianni et al24	No information	Low	Low	No information	Serious	Serious	Serious
Park and Lavin25	Low	Moderate	Low	Moderate	No information	Low	Moderate
Reid et al34	Low	Low	Low	Low	No information	Serious	Low
Saunders et al46	Serious	Low	Low	Low	Low	Serious	Low
Gallagher et al7	Moderate	Moderate	Low	Low	Low	Serious	Low
Raffaeli et al36	Serious	Low	Serious	Moderate	Low	Serious	Serious
Unützer et al26	Serious	Serious	Low	Low	Low	Serious	Low
Rigler et al37	Critical	Serious	Serious	Moderate	Low	Serious	Moderate
Soloman et al38	Low	Low	Low	Moderate	Moderate	Low	Low
Won et al39	Serious	Low	Serious	Low	Low	Serious	Moderate
Unützer et al27	Critical	Low	Low	Low	Low	Serious	Low
Won et al28	Serious	Low	Low	Moderate	Moderate	Low	Moderate
Kung et al40	Low	Low	Low	Low	Low	Serious	Moderate
Nassar et aal29	Moderate	Moderate	Low	Moderate	Low	Serious	Serious

Abbreviation: ROBINS-I, Risk of Bias in Nonrandomized Studies of Interventions.