Table 2.

Summary of study limitations using the GRADE criteria

Study	Risk of bias
	Failure to develop and apply appropriate eligibility criteria (selection bias)	Flawed measurement of exposure and outcome (detection bias)		Failure to adequately control confounding	Incomplete followup (attrition bias) (loss to followup)
		Exposure (joint arthroplasty)	Outcome (weight assessment)
Stets et al. [34]	High	Low	High	High	Low (0%)
Woodruff and Stone [36]	High	Low	Unclear	High	Low (0%)
Heisel et al. [17]	High	Low	Unclear	High	Low (0%)
Abu-Rajab et al. [1]	High	Low	Low	Low	Low (0%)
Donovan et al. [10]	Unclear	Low	Unclear	High	High (27%)
Aderinto et al. [2]	Unclear	Low	Unclear	High	Low (2.1%)
Middleton and Boardman [26]	Unclear	Low	Unclear	High	Low (0%)
Jain et al. [18]	Low	Low	High	High	High (20%)
Dowsey et al. [11]	Low	Low	Low	High	Low (1.5%)
Dowsey et al. [12]	Low	Low	Low	High	Low (1.5%)
Lachiewicz and Lachiewicz [22]	Moderate	Low	Low	Moderate	High (19%)
Zeni and Snyder-Mackler [37]	High	Low	Low	High	Low (0%)

GRADE = Grading of Recommendations Assessment, Development, and Evaluation.