Table 2. Baseline characteristics of patients included in the meta-analysis.

Study	Year	Stage	Criteria used to define rectal cancer	Median follow-up(year)	Surgery	Quality score
Stockholm 1	1980–1987	Any stage resectable	below sacral promontory	4.5	AP/anterior resection	0.74
Stockholm 2	1987–1993	Any stage resectable	below sacral promontory	9	AP/anterior resection	0.88
Swedish trial	1987–1990	T1-3	below sacral promontory	13	AP/anterior resection	0.82
Uppsala	1980–1985	Dukes A/B/C	NA	Minimum 5	AP/anterior resection	054
Dutch TME trial	1996–1999	Any stage resectable	15 cm from anal verge, below S1-2	12	AP/anterior resection with TME technique	0.88
MRC CR07	1998–2005	I-III	NA	4	APR/non-APR with TME technique	0.83
Polish trial	1999–2002	T3 or resectable T4	inferior edge palpable of digital exam	4	AP/anterior resection or Hartman with TME	1
TROG 01.04	2001–2006	cT3N any	within 12 cm of the anal verge	5.9	APR/non-APR with TME technique	0.81