Cochrane handbook for systematic reviews of interventions

704 Pages·2020·4.93 MB·English

by  Higgins, Julian P. T

Cochrane Handbook for
Systematic Reviewsof
Interventions
Cochrane Handbook for
Systematic Reviews of
Interventions
Second Edition
Edited by Julian P.T. Higgins, James Thomas,
Jacqueline Chandler, Miranda Cumpston, Tianjing Li,
Matthew J. Page and Vivian A. Welch
Thiseditionfirstpublished2019
©2019TheCochraneCollaboration
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Names:Higgins,JulianP.T.,editor.|CochraneCollaboration,issuingbody.
Title:Cochranehandbookforsystematicreviewsofinterventions/editedby
JulianP.T.Higgins,JamesThomas,JacquelineChandler,MirandaCumpston,
TianjingLi,MatthewJ.Page,VivianA.Welch.
Othertitles:Cochranebookseries.
Description:Secondedition.|Hoboken,NJ:Wiley-Blackwell,2019.|Series:
Cochranebookseries|Includesbibliographicalreferencesandindex.|
“Thisworkisaco-publicationbetweenTheCochraneCollaborationandJohn
Wiley&SonsLtd.”–ECIPtitlepageverso.
Identifiers:LCCN2019024539|ISBN9781119536628(hardback)|ISBN
9781119536611(adobepdf)|ISBN9781119536659(epub)
Subjects:|MESH:OutcomeandProcessAssessment(HealthCare)|
Evidence-BasedMedicine–methods|Meta-AnalysisasTopic|Systematic
ReviewsasTopic
Classification:LCCRA427.3|NLMW84.41|DDC362.1–dc23LCrecordavailableathttps://lccn.loc.gov/2019024539
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Contents
Contributors xiii
Preface xxiii
PartOne Coremethods 1
1 Startingareview 3
1.1 Why do a systematic review? 3
1.2 What is the review question? 4
1.3 Who should do a systematic review? 5
1.4 Theimportance of reliability 7
1.5 Protocol development 8
1.6 Data management and quality assurance 11
1.7 Chapter information 12
1.8 References 12
2 Determiningthescopeofthereviewandthequestionsitwilladdress 13
2.1 Rationale for well-formulated questions 13
2.2 Aims of reviews of interventions 15
2.3 Defining the scope of a review question 16
2.4 Ensuring the review addresses the right questions 21
2.5 Methods and tools for structuring the review 24
2.6 Chapter information 29
2.7 References 29
3 Definingthecriteriaforincludingstudiesandhowtheywillbegrouped
forthesynthesis 33
3.1 Introduction 33
3.2 Articulating the review and comparison PICO 35
3.3 Determining which study designs to include 51
3.4 Eligibility based on publication status and language 60
3.5 Chapter information 61
3.6 References 61
v
Contents
4 Searchingforandselectingstudies 67
4.1 Introduction 68
4.2 General issues 68
4.3 Sourcestosearch 70
4.4 Designing search strategies 79
4.5 Documenting and reporting thesearch process 90
4.6 Selecting studies 92
4.7 Chapter information 99
4.8 References 99
5 Collectingdata 109
5.1 Introduction 109
5.2 Sourcesof data 110
5.3 What data to collect 114
5.4 Data collection tools 125
5.5 Extracting data from reports 130
5.6 Extractingstudyresultsandconvertingtothedesiredformat 136
5.7 Managingand sharing data 136
5.8 Chapter information 137
5.9 References 137
6 Choosingeffectmeasuresandcomputingestimatesofeffect 143
6.1 Types of data and effect measures 143
6.2 Study designs and identifying the unit of analysis 145
6.3 Extracting estimates of effect directly 148
6.4 Dichotomous outcome data 150
6.5 Continuous outcome data 156
6.6 Ordinal outcome data and measurement scales 168
6.7 Countand rate data 170
6.8 Time-to-eventdata 172
6.9 Conditional outcomesonly available for subsets of participants 173
6.10 Chapter information 174
6.11 References 174
7 Consideringbiasandconflictsofinterestamongtheincludedstudies 177
7.1 Introduction 177
7.2 Empirical evidence of bias 180
7.3 General procedures for risk-of-biasassessment 185
7.4 Presentation of assessment of riskof bias 188
7.5 Summary assessments of risk of bias 188
7.6 Incorporatingassessmentof risk of bias into analyses 190
7.7 Consideringrisk of bias due to missing results 192
7.8 Consideringsourceoffundingandconflictofinterestofauthorsofincluded
studies 193
7.9 Chapter information 199
7.10 References 199
vi
Contents
8 Assessingriskofbiasinarandomizedtrial 205
8.1 Introduction 205
8.2 Overview of RoB 2 206
8.3 Bias arising from the randomization process 212
8.4 Bias due todeviations from intended interventions 214
8.5 Bias due tomissing outcome data 217
8.6 Bias in measurement of the outcome 220
8.7 Bias in selection of the reported result 221
8.8 Differences from the previous version of the tool 225
8.9 Chapter information 226
8.10 References 227
9 Summarizingstudycharacteristicsandpreparingforsynthesis 229
9.1 Introduction 229
9.2 A general frameworkfor synthesis 230
9.3 Preliminary steps of a synthesis 231
9.4 Checking data before synthesis 238
9.5 Types of synthesis 238
9.6 Chapter information 240
9.7 References 240
10 Analysingdataandundertakingmeta-analyses 241
10.1 Do not starthere! 242
10.2 Introduction tometa-analysis 242
10.3 A generic inverse-variance approach to meta-analysis 245
10.4 Meta-analysis of dichotomous outcomes 246
10.5 Meta-analysis of continuous outcomes 251
10.6 Combiningdichotomous and continuous outcomes 254
10.7 Meta-analysis of ordinal outcomesand measurement scales 255
10.8 Meta-analysis of counts and rates 255
10.9 Meta-analysis of time-to-eventoutcomes 256
10.10 Heterogeneity 257
10.11 Investigating heterogeneity 265
10.12 Missing data 272
10.13 Bayesianapproaches to meta-analysis 276
10.14 Sensitivity analyses 277
10.15 Chapter information 279
10.16 References 280
11 Undertakingnetworkmeta-analyses 285
11.1 What isnetwork meta-analysis? 285
11.2 Important concepts 287
11.3 Planning a Cochrane Review tocompare multiple interventions 293
11.4 Synthesis of results 297
11.5 Evaluating confidence in the results of a network meta-analysis 304
11.6 Presenting network meta-analyses 309
vii
Contents
11.7 Concluding remarks 315
11.8 Chapter information 316
11.9 References 316
12 Synthesizingandpresentingfindingsusingothermethods 321
12.1 Why a meta-analysisof effect estimates may not be possible 321
12.2 Statisticalsynthesiswhenmeta-analysisofeffectestimatesisnotpossible 324
12.3 Visual display and presentation of the data 330
12.4 Worked example 333
12.5 Chapter information 345
12.6 References 346
13 Assessingriskofbiasduetomissingresultsinasynthesis 349
13.1 Introduction 350
13.2 Minimizing risk of bias due tomissing results 351
13.3 Aframeworkforassessingriskofbiasduetomissingresultsinasynthesis 354
13.4 Summary 369
13.5 Chapter information 370
13.6 References 370
14 Completing‘Summaryoffindings’tablesandgradingthecertaintyofthe
evidence 375
14.1 ‘Summary of findings’ tables 375
14.2 Assessing the certainty or quality of a body of evidence 389
14.3 DescribingtheassessmentofthecertaintyofabodyofevidenceusingtheGRADE
framework 398
14.4 Chapter information 399
14.5 References 399
15 Interpretingresultsanddrawingconclusions 403
15.1 Introduction 403
15.2 Issues of indirectness and applicability 405
15.3 Interpretingresults of statistical analyses 408
15.4 Interpretingresults from dichotomous outcomes(includingnumbers needed
to treat) 411
15.5 Interpretingresults from continuous outcomes (including standardized mean
differences) 416
15.6 Drawingconclusions 422
15.7 Chapter information 427
15.8 References 428
PartTwo Specificperspectivesinreviews 433
16 Equityandspecificpopulations 435
16.1 Introduction toequity in systematic reviews 435
16.2 Formulation of thereview 437
viii
Contents
16.3 Identification of evidence 441
16.4 Appraisal of evidence 443
16.5 Synthesis of evidence 443
16.6 Interpretation of evidence 444
16.7 Concluding remarks 445
16.8 Chapter information 445
16.9 References 445
17 Interventioncomplexity 451
17.1 Introduction 451
17.2 Formulationof the review 461
17.3 Identification of evidence 468
17.4 Appraisal of evidence 469
17.5 Synthesis of evidence 469
17.6 Interpretation of evidence 472
17.7 Chapter information 473
17.8 References 474
18 Patient-reportedoutcomes 479
18.1 Introductionto patient-reported outcomes 479
18.2 Formulationof the review 480
18.3 Appraisal of evidence 482
18.4 Synthesis and interpretation of evidence 485
18.5 Chapter information 488
18.6 References 489
19 Adverseeffects 493
19.1 Introductionto issues in addressing adverse effects 493
19.2 Formulationof the review 496
19.3 Identification of evidence 500
19.4 Appraisal of evidence 502
19.5 Synthesis and interpretation of evidence 503
19.6 Chapter information 504
19.7 References 505
20 Economicevidence 507
20.1 Introduction 507
20.2 Formulationof the review 512
20.3 Identification of evidence 517
20.4 Appraisal of evidence 519
20.5 Synthesis and interpretation of evidence 519
20.6 Chapter information 521
20.7 References 522
21 Qualitativeevidence 525
21.1 Introduction 525
ix
Contents
21.2 Designsforsynthesizingandintegratingqualitativeevidencewithintervention
reviews 526
21.3 Definingqualitative evidenceand studies 527
21.4 Planningaqualitativeevidencesynthesislinkedtoaninterventionreview 528
21.5 Question development 529
21.6 Questions exploring intervention implementation 530
21.7 Searching forqualitative evidence 531
21.8 Assessingmethodologicalstrengthsandlimitationsofqualitativestudies 532
21.9 Selectingstudiesto synthesize 533
21.10 Selectinga qualitative evidence synthesis and data extraction method 534
21.11 Data extraction 534
21.12 Assessing the confidence in qualitative synthesized findings 537
21.13 Methodsforintegratingthequalitativeevidencesynthesiswithanintervention
review 537
21.14 Reporting the protocol and qualitative evidence synthesis 538
21.15 Chapter information 539
21.16 References 539
PartThree Furthertopics 547
22 Prospectiveapproachestoaccumulatingevidence 549
22.1 Introduction 549
22.2 Evidence surveillance: active monitoring of the accumulating evidence 550
22.3 Prospectively planned meta-analysis 554
22.4 Statistical analysis of accumulating evidence 561
22.5 Chapter information 564
22.6 References 565
23 Includingvariantsonrandomizedtrials 569
23.1 Cluster-randomizedtrials 569
23.2 Crossover trials 576
23.3 Studieswithmore than two intervention groups 585
23.4 Chapter information 590
23.5 References 591
24 Includingnon-randomizedstudiesoninterventioneffects 595
24.1 Introduction 595
24.2 Developingcriteriaforincludingnon-randomizedstudiesofinterventions 601
24.3 Searching fornon-randomized studies of interventions 606
24.4 Selectingstudiesand collecting data 608
24.5 Assessing risk of bias in non-randomized studies 610
24.6 Synthesis of results from non-randomized studies 611
24.7 Interpretation and discussion 614
24.8 Chapter information 617
24.9 References 617
x