Clinical effect of operative vs nonoperative treatment on humeral shaft fractures: Systematic review and meta-analysis of clinical trials

Table 2 Quality assessment of the 13 cohort studies using the Newcastle-Ottawa Scale

Ref.	Selection	Comparability	Outcome	Total	Study quality
Wallny et al[32]	++++	+	++	7 +	High
Jawa et al[15]	++++		++	5 +	High
Oliver et al[27]	++++		++	5 +	High
Westrick et al[19]	++++		++	5 +	High
Mahabier et al[16]	++++	++	+++	9 +	High
Harkin and Large[18]	+++	+	+	5 +	High
Dielwart et al[28]	+++	+	++	6 +	High
Osman et al[31]	+++		+	4 +	Low
Ekholm et al[30]	+++	+	+++	7 +	High
Denard et al[29]	+++	+	+	5 +	High
Den Hartog et al[17]	++++	+	+++	8 +	High
van Middendorp et al[11]	++++	+	++	7 +	High
Cannada et al[33]	++	+	+	4 +	Low

Scale: Zero to 9 +; 5 or more + indicates a higher quality study.