the appraisers were blinded to each other's identities.

To test the guide's use in practice (stage 5), appraisers were sent one of five selected, brief or comprehensive tiffany jewellery reviews that had been produced to support an HIA and asked to judge the review against the essential steps for a brief evidence review listed in the guide plus, if relevant, additional elements recommended for a "more comprehensive" review.24 In particular, appraisers were asked whether the review was "of sufficient quality" to be made widely tiffany jewellery. Where possible, the author or authors of the evidence review and the appraisers were blinded to each other's identities.

In stage 6, the final version of the guide was produced in a hard-copy form25 and made publicly available in tiffany jewellery 2006 as a free downloadable Adobe Acrobat document on a nationally recognized public health web site in the United Kingdom of Great Britain and Northern Ireland,26 along with various supporting resources. The guide was also made available on a United Kingdom HIA web site.27 As a proxy estimate of the guide's use in the field, the number of downloads from the guide's web sites26,27 was ascertained.

The criteria specifying the nature of the guide were developed following a scoping review of the literature and of existing tiffany jewellery on reviewing different types of evidence, such as systematic reviews,28 qualitative studies29 and non-randomized studies. The criteria included: the clarity of purpose and provenance of the review; the rationale for the review process; the processes employed by the review, including search strategies and inclusion and exclusion criteria; the quality of the research and the "strength" of the evidence; acknowledgement of likely biases; a sum- mary of the conclusions drawn; and the limitations of the review. Consultations during this phase led to pivotal decisions being made about the purpose, presenta- tion, format and content of the tiffany jewellery.