Table 3. Grading of Recommendation Assessment, Development and Evaluation classification per significant prognostic factor for return to work and work disability.

	GRADE factors								Overall quality
	Phase of investigation	Study limitations	Inconsis-tency	Indirectness	Imprecision	Publication bias	Moderate / large effect size	Dose effect
Return to work
Age	√	✘	✘	✘	√	√	NA	✘	+
(Neo)adjuvant therapy	√	✘	√	√	✘	√	NA	✘	+ +
Comorbidites	√	✘	✘	✘	√	√	NA	✘	+
Work disability
Type of surgery	√	✘	√	✘	√	√	NA	✘	+ +
Postoperative complications	√	✘	√	√	√	√	NA	✘	+ + +
Previous unemployment	✘	✘	√	√	√	√	NA	✘	+ +

Grading of Recommendation Assessment, Development and Evaluation factors:

√ = no serious limitations

✘ = serious limitiations

NA = not applicable or unknown

For overall quality of evidence:

+ = very low

++ = low

+++ = moderate.