Table 2.

Criteria for inclusion of epidemiological studies¹

Characteristic	Desirable	Undesirable
1. Subjects2	Population-based	Tertiary-care
2. Case-definition2	Clear and standardized	Patient recall or standard of care
3. Peer-reviewed2	Published	Meeting only or published non-reviewed supplement
4. Survey instrument3	NIH-CPSI4, with evaluation for exclusion criteria	None
5. Survey-strategy3	Standardized and representative Clinical verification to exclude inappropriate cases	Retrospective record review No clinical evaluation
6. Population size3	Sufficient to provide statistical power	Small, providing low statistical power

¹Modified from reference [2]with the additional requirement that studies be published in the peer-reviewed literature.

²Characteristics 1, 2, and 3 were required for inclusion in this review.

³In addition, each study had to have at least one other desirable characteristic (4, 5, or 6).

⁴Use of the NIH-CPSI was considered a desirable study characteristic, but this was not required for inclusion in this systematic review.