Evidence-based Medicine Toolkit

Index 103statistical significance 45validity 43–4Health Technology AssessmentDatabase 12, 13health technology assessments(HTAs) 9, 11heterogeneityclinical 30statistical 30incremental costs and benefits 67in-depth interviews 60intention-to-treat analysis 52internetassessing web sites 19search engines 19searching 18–19useful web sites 85–93intervention 3, 4clinical applicability 75comparison 3, 4, 75–6interviewsin depth 60focus group 60journals, secondary 11kappa statistic 36likelihood ratio (LR) 37, 38, 39calculation 34nomogram 41limit (the search) 16, 17MEDLINE 14AskMedline 18search ‘filters’ 17search strategies 14–17meta-analysis 28National Guideline Clearinghouse,US 10National Institute for ClinicalExcellence (NICE) 10National Library for Health, UK 10NEAR, proximity 17negative predictive value 38New Zealand Guidelines Group10NHS Economic EvaluationDatabase 12NHS Health TechnologyAssessment database 12, 13NNT see number needed to treatNOT (Boolean) 16, 17number needed to harm (NNH) 44number needed to treat (NNT) 50,56–7individual patient 27, 32, 74–5observationconcealed participant 60participant 60passive 60observer bias 53, 61odds 32logarithmic 32post-test 38, 73pre-test 38, 73odds ratio 32, 42, 44, 45OR (Boolean) 16, 17outcomes (outcome measures)3, 4–5clinical significance 76economic evaluations 68harm/aetiology studies 43prognosis studies 48research 95therapy studies 53participants, study‘blinding’ 52–3diagnosis studies 35lost to follow-up 47–8, 52qualitative research 60–1, 63representativeness 47vs. real-world patients 72see also groups, study