Roberts 2007.

Methods	Study design: ITS
Participants	Physicians Clinical speciality: prosthetic care Level of training: fully trained Setting/country: outpatient (e.g. ambulatory care provided by hospitals/specialists)/UK
Interventions	The PEM studied in this report was the Technology Appraisal Guidance No. 2 ‐ Guidance on the selection of protheses for primary total hip replacements (April 2000). TAG No. 2 contained a recommendation that cemented protheses be used
Outcomes	2 process outcomes: percentage use of uncemented prostheses percentage use of hybrid prostheses of all hips implanted
Notes	‐
Risk of bias
Bias	Authors' judgement	Support for judgement
Intervention independent of other changes ‐ ITS	Unclear risk	No information was provided
Shape of Intervention effect pre‐specified ‐ ITS	Unclear risk	Quote, pg. 864: "in April 2000, NICE published the Technology Appraisal Guidance (TAG) No. 2 ‐ ‘Guidance on the selection of prostheses for Primary Total Hip Replacements. […] As more than five years have passed since the publication of these guidelines, we decided to review the effect it has had, and the extent to which the guidelines have influenced clinical practice and contracting"
Intervention unlikely to affect data collection ‐ ITS	Low risk	The intervention (NICE Technology Appraisal Guideline 2) did not affect either the source or method of data collection
Blinding of outcome assessors (detection bias) ‐ ITS All outcomes	Low risk	The outcome was objective
Incomplete outcome data (attrition bias) ‐ ITS All outcomes	Unclear risk	Quote, pg. 865: "since the beginning of 1990, and with the agreement of all consultant orthopaedic surgeons in the region, all primary total hip and knee replacements (THR, TKR) performed throughout the Trent region were recorded prospectively" COMMENT: it is unlikely that there would be a difference in missing data before and after implementation of the intervention
Selective reporting (reporting bias) ‐ ITS	Low risk	All relevant outcomes in the methods section were reported in the results section
Other bias ‐ ITS	Low risk	There was no evidence of other risks of bias