Table 1.

Descriptive characteristics of studies selected for inclusion in the review

Author	Year of publication	Country	Study design	Study period	Sample size	Relapse proportion (at 2 weeks)
Rowe33	2007	Canada	Randomised controlled trial	–	137	12.40%
McCarren24	1998	USA	Prospective cohort	1992–1995	284	10%
Emerman26	1999	USA	Prospective cohort	1996–1997	641	17%
Singh28	1999	USA	Prospective cohort	1996–1997	1228	15.80%
Rowe22	2008	Canada	Prospective cohort	2004–2005	695	13.90%
Rowe23	2015	Canada	Prospective cohort	2003–2007	807	14%
Lin29	2009	Canada	Retrospective cohort	2006–2007	257	–
Prabhakaran30	2013	Singapore	Retrospective cohort	2008–2009	1303	7.4% (4 week)
Baibergenova31	2006	Canada	Administrative database	2003–2004	23 253	–
Withy32	2008	USA	Administrative database	1999–2004	4318	4%