Table 4.

Observation study methodology - methodological quality criteria for assessment of observational studies⁹⁵

First Author (Year)	Relevant subjects	Appropriate inclusion criteria	Prospective investigation (stated)	Adequate follow-up (1 year after final treatment)	Lost to follow-up accounted for	Blinded assessment (stated)	Appropriate impairment outcomes	Appropriate disability outcomes	Total Score
Itoi (1992)109	✔	✔	✗	✗	✔All present	✗	✔	✔	5/8
Bokor (1993)105	✔	✔	✗	✔	✔	✗	✔	✔	6/8
Hawkins (1995)108	✔	✔	✔	✔	✔	✗	✔	✔	7/8
Wirth (1997)114	✔	✔	✔	✔	✔	✗	✔	✔	5/8
Palmer (1998)101	✔	✔	✗	✔	✔ All present	✗	✔	None measured	5/8
Yamada (2000)115	✔	✔	✗	✔	✔	✗	✔	✔	6/8
Goldberg (2001)107	✔	✔	✗	✔	✔ All present	✗	None measured	✔	5/8
Vad (2002)120	✔	✔	✗	✔	✔ All present	✗	None measured	✔	5/8
Piccoli (2004)102	✔	✔	✗	✗	✔ All present	✗	✔	✔	5/8
Ainsworth (2006)104	✔	✔	✗	✗	✔ All present	✗	None measured	✔	4/8
Levy (2007)116	✔	✔	✔	✗	✔ All present	✗	✔	✔	6/8
Lunn (2007)119	✔	✔	✗	✔	✔ All present	✗	None measured	✔	5/8
Baydar (2009)118	✔	✔	✔	✔	✔	✗	✔	✔	7/8
Tanaka (2010)113	✔	✔	✗	✔	✔ All present	✗	✔	✔	6/8
Merolla (2011)1	✔	✔	✔	✔	✔ All present	✗	✔	✔	7/8
Kijma (2012)110	✔	✔	✔	✔	✔	✗	None measured	✔	7/8
Kuhn (2013)40	✔	✔	✔	✔	✔	✗	✔	✔	7/8
Benazzo (2014)99	✔	✔	✗	✔	✔ All present	✗	✔	✔	6/8
Boorman (2014)123	✔	✔	✔	✔	✔	✔	✔	✔	8/8
Güzelant (2014)117	✔	✔	✗	✔	✔	✗	✔	✔	6/8
Collin (2015)106	✔	✔	✔	✔	✔	✗	✔	✔	7/8
Baumer (2016)121	✔	✔	✔	✗	✔	✗	✔	✔	6/8
Christensen (2016)122	✔	✔	✔	✗	✔	✔	✔	✔	7/8
Miller (2016)111	✔	✔	✔	✗	✔ All present	✗	✔	✔	6/8
Mischke (2016)100	✔	✔	✗	✔	✔ All present	✗	✔	✔	6/8
Upadhyaya (2016)103	✔	✔	✗	✔	✔ All present	✗	✔	None measured	5/8
Moosmayer (2017)112	✔	✔	✗	✔	✔	✔	✔	✔	7/8