Table 1.

Methodological quality of included articles

First author	No. of cases	Q1	Q2	Q3	Q4	Q5	Q6	Overall Quality
Johenning 8	2	Yes	No	Yes	No	Unclear	Yes	Intermediate
Kossow 12	1	Unclear	No	No	No	Unclear	Yes	Low
May 13	2	Yes	Yes	Yes	Yes	Unclear	Yes	High
McNellis 9	4	Yes	Yes	Yes	Yes	Unclear	Yes	High
Redman 14	1	Unclear	No	No	No	Unclear	Yes	Low
Vorstman 15	1	Unclear	Yes	Yes	Yes	Unclear	Yes	High
Naughton 16	1	Unclear	Yes	No	Yes	Unclear	Yes	Intermediate
Thurston 17	5	Yes	No	Yes	No	Yes	Yes	High
Tawil 18	1	Unclear	No	No	No	Unclear	Yes	Low
Kuntze 19	2	Yes	Yes	Yes	Yes	Unclear	Yes	High
Gillion 11	2	Yes	Yes	Yes	Yes	Unclear	Yes	High
Hulecki 20	1	Unclear	Yes	No	Yes	Unclear	Yes	Intermediate
Morgan 21	1	Unclear	Yes	No	Yes	Unclear	Yes	Intermediate
Phillips 22	1	Unclear	Yes	No	Yes	Unclear	Yes	Intermediate
Steinbruchel 23	2	Yes	No	No	No	Unclear	Yes	Low
O'Shaughnessy 24	2	Yes	Yes	Yes	Yes	Unclear	Yes	High
Hurren 25	2	Yes	Yes	No	Yes	Unclear	Yes	High
Chinegwundoh 26	1	Unclear	Yes	No	Yes	Unclear	Yes	Intermediate
Rasmussen 27	2	Yes	No	No	No	Unclear	No	Low
Von Zastrow 28	4	Yes	Yes	No	Yes	Unclear	Yes	High
De Vylder 10	3	Yes	Yes	No	Yes	Unclear	Yes	High
Blaut 29	2	Yes	No	No	No	Unclear	No	Low
Van Glabeke 30	1	Unclear	No	No	No	Unclear	Yes	Low
Alnadhari 31	1	Unclear	No	No	No	Unclear	Yes	Low
Koochakzadeh 32	1	Unclear	Yes	Yes	Yes	Unclear	Yes	High
Wang 33	1	Unclear	Yes	No	Yes	Unclear	Yes	Intermediate

Abbreviation: Q, question.

Note: *Questions 1–6 comprise the tool for assessing the methodological quality of each of the included articles:

1. Does the patient(s) represent(s) the whole experience of the investigator or is the selection method unclear to the extent that other patients with similar presentation may not have been reported?
2. Was the condition adequately ascertained?
3. Was the outcome adequately ascertained?
4. Were other alternative causes that may explain the observation ruled out?
5. Was follow‐up long enough for outcomes to occur?
6. Is the case(s) described with sufficient details to allow other investigators to replicate the research or to allow practitioners to make inferences related to their own practice?