Adjuvant Second-Dose Chemotherapy before Surgery for Patients with Locally Advanced Rectal Malignancy Is Not Beneficial: A Systematic Review and Meta-Analysis

Table 3

Risk of bias in the nonrandomized studies using modified Newcastle-Ottawa scale.

Study	Selection			Comparability		Outcome		Quality score
	Assign for treatment^△	Representative treatment group	Representative reference group	Comparable for 1, 2, 3, 4, and 5	Comparable for 6, 7, 8, and 9	Assessment of outcome	Adequate follow-up
Calvo et al. [32]	No	Yes	Yes	1, 2, and 3	6, 7, and 8	Yes	Yes	★★★★★★
Garcia-Aguilar et al. [33]	No	Yes	Yes	1, 2, 3, and 4	6, 7, and 8	Yes	Yes	★★★★★★

Comparability variables: 1, age; 2, gender; 3, TN; 4, total mesorectal excision; 5, radial margin status; 6, distance from anal verge; 7, radiotherapy technique; 8, total dose of radiotherapy; and 9, adjuvant chemotherapy. If all characteristics were comparable, two stars; if >2 characteristics were comparable, one star; if <2 characteristics were comparable, no star. ^△The article provided the details of criteria for adequate random assignment.