Table 1

Appropriateness of different types of evidence for answering public health questions (reproduced with permission, National Institute for Health and Clinical Excellence (NICE), 2009)

Type of evidence
Systematic review of effectiveness (and cost-effectiveness)Experimental studyObservational studyQualitative studyPractice/case reportEconomic/cost-effectiveness study
Research question
 Extent of public health problem/issueNICE epidemiological review
 Factors/determinants/associationsNICE review of reviewsNICE correlates review
 Intervention effectiveness/cost-effectivenessNICE review of reviewsNICE effectiveness review (can include observational and qualitative studies as well as experimental studies)NICE cost-effectiveness review
 Views and experiences of practitionersNICE correlates reviewNICE qualitative reviewNICE mapping report
 Views and experiences of target populationNICE correlates reviewNICE qualitative review