Appendix C.

Risk of Bias Assessment for Observational Studies (Newcastle Ottawa Scale)

	Selection			Comparability		Outcome
Study	Representativeness of exposed cohorta	Selection of nonexposed cohortb	Ascertainment of exposure(s)b	Demonstration that mobility disorders/problems were not present at startc	Comparability of cohortsc	Assessment of outcomed	Was follow-up long enough for outcome to occur?e	Adequacy of follow-upf
Duclos et al. (14)	◑					●	○	○
Grap et al (13)	◑					●	○	○
Grap et al. (4)	◑					●	◑	○
Grap et al. (12)	◑					●	○	○
Mistraletti et al. (8)	◑					●	○	○
Osse et al. (9)	◑					●	○	○
Osse et al. (10)	◑					●	○	○
Paul et al. (6)	◑					●	○	○
Redeker et al. (1)	◑					●	○	◑
Redeker et al. (2)	●					●	○	○
Whetstone Foster et al. (5)	●					●	●	○
Winkelman et al. (7)	○					●	●	◑
Winkelman et al. (3)	●					●	◑	○
Winkelman (11)	●					●	○	○

^●= High Risk of Bias

^◑= Unclear Risk of Bias

^○= Low Risk of Bias

^aHigh Risk if not consecutively screened, chosen based on specific criteria

^bOnly applicable for studies with a pre-defined exposure

^cOnly applicable for Cohort studies

^dHigh Risk if not compared to other scale (i.e., PSG)

^eHigh Risk if individual study period <24 hours, Low Risk if >24 hours

^fHigh Risk if >10% lost to follow up, Low Risk if <10% lost to follow up