Are patients willing to accept longer travel times to decrease their risk associated with surgical procedures? A systematic review

Table 3 Risk of bias

	Finlayson	Landau	Chang	Shalowitz	Burkamp
Domain 1: Study population
1. Was an appropriate study sample selected from the sampling frame?	N	PN	N	PY	PY
Risk of bias in domain 1	critical	serious	critical	moderate	moderate
Domain 2: Instrument
2. Was the chosen instrument for eliciting relative importance of outcomes valid and reliable?	PN	PN	PN	PN	PN
3. Was the instrument administered in the intended way?	PY	PY	PY	PY	PY
4. Was a valid representation of the outcome^a used?	PN	PN	PN	Y	Y
5. Did the researchers check the understanding of the measurement instrument?	The investigators did not formally test the understanding, but there was evidence suggesting inadequate understanding.	The investigators did not formally test the understanding, but there was evidence suggesting inadequate understanding.	The investigators did not formally test the understanding, but there was evidence suggesting inadequate understanding.	The investigators did not formally test the understanding, but there was evidence suggesting adequate understanding.	The investigator tested the understanding and understanding was adequate
Risk of bias in domain 2	serious	serious	serious	moderate	moderate
Domain 3: Analysis
6. Were the results analysed appropriately to avoid influence of bias and confounding?	PY	PY	PY	PY	PY
Risk of bias in domain 3	moderate	moderate	moderate	moderate	moderate
Risk of bias within study	serious	serious	serious	moderate	moderate

Modification of Zhang, Y., et al., GRADE Guidelines: 19. Assessing the certainty of evidence in the importance of outcomes or values and preferences -- Risk of bias and indirectness. J Clin Epidemiol, 2018 [10].
^aRoB rated for outcomes mortality risk, revision and survival; N No, PN probably no, PY probably yes, Y Yes

ISSN: 1471-2458