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BMC Medical Research Methodology
Published in: BMC Medical Research Methodology 1/2018

Open Access 01-12-2018 | Research article

Methods to systematically review and meta-analyse observational studies: a systematic scoping review of recommendations

Authors: Monika Mueller, Maddalena D’Addario, Matthias Egger, Myriam Cevallos, Olaf Dekkers, Catrina Mugglin, Pippa Scott

Published in: BMC Medical Research Methodology | Issue 1/2018

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Abstract

Background

Systematic reviews and meta-analyses of observational studies are frequently performed, but no widely accepted guidance is available at present. We performed a systematic scoping review of published methodological recommendations on how to systematically review and meta-analyse observational studies.

Methods

We searched online databases and websites and contacted experts in the field to locate potentially eligible articles. We included articles that provided any type of recommendation on how to conduct systematic reviews and meta-analyses of observational studies. We extracted and summarised recommendations on pre-defined key items: protocol development, research question, search strategy, study eligibility, data extraction, dealing with different study designs, risk of bias assessment, publication bias, heterogeneity, statistical analysis. We summarised recommendations by key item, identifying areas of agreement and disagreement as well as areas where recommendations were missing or scarce.

Results

The searches identified 2461 articles of which 93 were eligible. Many recommendations for reviews and meta-analyses of observational studies were transferred from guidance developed for reviews and meta-analyses of RCTs. Although there was substantial agreement in some methodological areas there was also considerable disagreement on how evidence synthesis of observational studies should be conducted. Conflicting recommendations were seen on topics such as the inclusion of different study designs in systematic reviews and meta-analyses, the use of quality scales to assess the risk of bias, and the choice of model (e.g. fixed vs. random effects) for meta-analysis.

Conclusion

There is a need for sound methodological guidance on how to conduct systematic reviews and meta-analyses of observational studies, which critically considers areas in which there are conflicting recommendations.
Appendix
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Literature
1.
2.
Funai EF, Rosenbush EJ, Lee MJ, Del Priore G. Distribution of study designs in four major US journals of obstetrics and gynecology. Gynecol Obstet Investig. 2001;51:8–11.CrossRef
3.
Scales CD, Norris RD, Peterson BL, Preminger GM, Dahm P. Clinical research and statistical methods in the urology literature. J Urol. 2005;174(4 Pt 1):1374–9.CrossRefPubMed
4.
5.
6.
7.
Page MJ, Shamseer L, Altman DG, Tetzlaff J, Sampson M, Tricco AC, et al. Epidemiology and reporting characteristics of systematic reviews of biomedical research: a cross-sectional study. PLoS Med. 2016;13:e1002028.CrossRefPubMedPubMedCentral
8.
Zwahlen M, Renehan A, Egger M. Meta-analysis in medical research: potentials and limitations. Urol Oncol. 2008;26:320–9.CrossRefPubMed
9.
10.
11.
Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JPA, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate healthcare interventions: explanation and elaboration. BMJ. 2009;339:b2700.CrossRefPubMedPubMedCentral
12.
Stroup DF, Berlin JA, Morton SC, Olkin I, Williamson GD, Rennie D, et al. Meta-analysis of observational studies in epidemiology: a proposal for reporting. Meta-analysis of observational studies in epidemiology (MOOSE) group. JAMA. 2000;283:2008–12.CrossRefPubMed
13.
Peters MDJ, Godfrey CM, Khalil H, Mcinerney P, Parker D, Soares CB. Guidance for conducting systematic scoping reviews. Int J Evid Based Heal. 2015;13:141–6.CrossRef
14.
Colquhoun HL, Levac D, Brien KKO, Straus S, Tricco AC, Perrier L, et al. Scoping reviews : time for clarity in definition, methods, and reporting. J Clin Epidemiol. 2014;67:1291–4.CrossRefPubMed
15.
Tricco AC, Lillie E, Zarin W, Brien KO, Colquhoun H, Kastner M, et al. A scoping review on the conduct and reporting of scoping reviews. BMC Med Res Methodol. 2016;16:15.CrossRefPubMedPubMedCentral
16.
Lau J, Ioannidis JP, Schmid CH. Quantitative synthesis in systematic reviews. Ann Intern Med. 1997;127:820–6.CrossRefPubMed
17.
Lilford RJ, Richardson A, Stevens A, Fitzpatrick R, Edwards S, Rock F, et al. Issues in methodological research: perspectives from researchers and commissioners. Health Technol Assess. 2001;5:1–57.CrossRefPubMed
18.
Rutjes A, Reitsma J, Coomarasamy A, Khan K, Bossuyt P. Evaluation of diagnostic tests when there is no gold standard. A review of methods. Health Technol Assess. 2007;11(50).
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
Khoshdel A, Attia J, Carney SL. Basic concepts in meta-analysis: a primer for clinicians. Int J Clin Pr. 2006;60:1287–94.CrossRef
31.
Friedenreich CM, Brant RF, Riboli E. Influence of methodologic factors in a pooled analysis of 13 case-control studies of colorectal cancer and dietary fiber. Epidemiology. 1994;5:66–79.CrossRefPubMed
32.
Chambers D, Rodgers M, Woolacott N. Not only randomized controlled trials, but also case series should be considered in systematic reviews of rapidly developing technologies. J Clin Epidemiol. 2009;62:1253–60. e4CrossRefPubMed
33.
Sagoo GS, Little J, Higgins JPT. Systematic reviews of genetic association studies. Human Genome Epidemiology Network PLoS Med. 2009;6:e28.PubMed
34.
Blair A, Burg J, Foran J, Gibb H, Greenland S, Morris R, et al. Guidelines for application of meta-analysis in environmental epidemiology. ISLI risk science institute. Regul Toxicol Pharmacol. 1995;22:189–97.CrossRefPubMed
35.
36.
Ashford D, Davids K, Bennett SJ. Difference-based meta-analytic procedures for between-participant and/or within-participant designs: a tutorial review for sports and exercise scientists. J Sport Sci. 2009;27:237–55.CrossRef
37.
Wells GA, Shea B, Higgins JPT, Sterne J, Tugwell P, Reeves BC. Checklists of methodological issues for review authors to consider when including non-randomized studies in systematic reviews. Res Synth Methods. 2013;4:63–77.CrossRefPubMed
38.
Simunovic N, Sprague S, Bhandari M. Methodological issues in systematic reviews and meta-analyses of observational studies in orthopaedic research. J Bone Jt Surg Am. 2009;91(Suppl 3):87–94.CrossRef
39.
Armstrong R, Waters E, editors. Systematic Reviews of Health Promotion and Public Health Interventions. Guidelines for Systematic Reviews in Health Promotion and Public Health Task Force. Version 2. Melbourne University: Australia.; 2007.
40.
Schünemann HJ, Tugwell P, Reeves BC, Akl EA, Santesso N, Spencer FA, et al. Non-randomized studies as a source of complementary, sequential or replacement evidence for randomized controlled trials in systematic reviews on the effects of interventions. Res Synth Methods. 2013;4:49–62.CrossRefPubMed
41.
Moola S, Munn Z, Sears K, Sfetcu R, Currie M, Lisy K, et al. Conducting systematic reviews of association (etiology): the Joanna Briggs Institute’s approach. Int J Evid Based Healthc. 2015;13:163–9.CrossRefPubMed
42.
O’Connor AM, Sargeant JM. Meta-analyses including data from observational studies. Prev Vet Med. 2014;113:313–22.CrossRefPubMed
43.
Ravani P, Ronksley PE, James MT, Strippoli GF. A nephrology guide to reading and using systematic reviews of observational studies. Nephrol Dial Transplant. 2015;30:1615–21.CrossRefPubMed
44.
Tufanaru C, Munn Z, Stephenson M, Aromataris E. Fixed or random effects meta-analysis? Common methodological issues in systematic reviews of effectiveness. Int J Evid Based Healthc. 2015;13:196–207.CrossRefPubMed
45.
Guyatt GH, Oxman AD, Kunz R, Atkins D, Brozek J, Vist G, et al. GRADE guidelines: 2. Framing the question and deciding on important outcomes. J Clin Epidemiol. 2011;64:395–400.CrossRefPubMed
46.
MacDonald-Jankowski DS, Dozier MF. Systematic review in diagnostic radiology. Dentomaxillofac Radiol. 2001;30:78–83.CrossRefPubMed
47.
Manchikanti L, Datta S, Smith HS, Hirsch JA. Evidence-based medicine, systematic reviews, and guidelines in interventional pain management: part 6. Systematic reviews and meta-analyses of observational studies. Pain Physician. 2009;12:819–50.PubMed
48.
Normand SL. Meta-analysis: formulating, evaluating, combining, and reporting. Stat Med. 1999;18:321–59.CrossRefPubMed
49.
Price D, Jefferson T, Demicheli V. Methodological issues arising from systematic reviews of the evidence of safety of vaccines. Vaccine. 2004;22:2080–4.CrossRefPubMed
50.
Raman G, Gaylor JM, Rao M, Chan J, Earley A, Chang LKW, et al. AHRQ methods for effective health care. In: Quality of reporting in systematic reviews of implantable medical devices. Rockville (MD): Agency for Healthcare Research and Quality (US); 2012.
51.
Rosenthal R, DiMatteo MR. Meta-analysis: recent developments in quantitative methods for literature reviews. Annu Rev Psychol. 2001;52:59–82.CrossRefPubMed
52.
Tak LM, Meijer A, Manoharan A, de Jonge P, Rosmalen JG. More than the sum of its parts: meta-analysis and its potential to discover sources of heterogeneity in psychosomatic medicine. Psychosom Med. 2010;72:253–65.CrossRefPubMed
53.
Thomas BH, Ciliska D, Dobbins M, Micucci S. A process for systematically reviewing the literature: providing the research evidence for public health nursing interventions. Worldviews Evid-Based Nurs. 2004;1:176–84.CrossRefPubMed
54.
Chaiyakunapruk N, Saokaew S, Sruamsiri R, Dilokthornsakul P. Systematic review and network meta-analysis in health technology assessment. J Med Assoc Thail. 2014;97(Suppl 5):S33–42.
55.
Mahid SS, Hornung CA, Minor KS, Turina M, Galandiuk S. Systematic reviews and meta-analysis for the surgeon scientist. Br J Surg. 2006;93:1315–24.CrossRefPubMed
56.
Wille-Jorgensen P, Renehan AG. Systematic reviews and meta-analyses in coloproctology: interpretation and potential pitfalls. Color Dis. 2008;10:21–32.
57.
Haynes RB, Kastner M, Wilczynski NL, Hedges T. Developing optimal search strategies for detecting clinically sound and relevant causation studies in EMBASE. BMC Med Inf Decis Mak. 2005;5:8.CrossRef
58.
59.
Furlan AD, Irvin E, Bombardier C. Limited search strategies were effective in finding relevant nonrandomized studies. J Clin Epidemiol. 2006;59:1303–11.CrossRefPubMed
60.
Golder S, Loke Y, McIntosh HM. Poor reporting and inadequate searches were apparent in systematic reviews of adverse effects. J Clin Epidemiol. 2008;61:440–8.CrossRefPubMed
61.
Thornton A, Lee P. Publication bias in meta-analysis: its causes and consequences. J Clin Epidemiol. 2000;53:207–16.CrossRefPubMed
62.
Kuper H, Nicholson A, Hemingway H. Searching for observational studies: what does citation tracking add to PubMed? A case study in depression and coronary heart disease. BMC Med Res Methodol. 2006;6:4.CrossRefPubMedPubMedCentral
63.
Lemeshow AR, Blum RE, Berlin JA, Stoto MA, Colditz GA. Searching one or two databases was insufficient for meta-analysis of observational studies. J Clin Epidemiol. 2005;58:867–73.CrossRefPubMed
64.
Loke YK, Golder SP, Vandenbroucke JP. Comprehensive evaluations of the adverse effects of drugs: importance of appropriate study selection and data sources. Ther Adv Drug Saf. 2011;2:59–68.CrossRefPubMedPubMedCentral
65.
Higgins JPT, Ramsay C, Reeves BC, Deeks JJ, Shea B, Valentine JC, et al. Issues relating to study design and risk of bias when including non-randomized studies in systematic reviews on the effects of interventions. Res Synth Methods. 2013;4:12–25.CrossRefPubMed
66.
Winegardner ML, Reaume KT, Dabaja GS, Kalus JS. Practical application of nonrandomized research to patient care: a case study of nesiritide. Pharmacotherapy. 2007;27:143–51.CrossRefPubMed
67.
68.
Stansfield C, Dickson K, Bangpan M, Oliver S, Bangpan M, Stansfield C, et al. Exploring issues in the conduct of website searching and other online sources for systematic reviews: how can we be systematic? Syst Rev. 2016;5:191.CrossRefPubMedPubMedCentral
69.
Thompson J, Davis J, Mazerolle L. A systematic method for search term selection in systematic reviews. Res Synth Methods. 2014;5:87–97.CrossRefPubMed
70.
71.
Norris SL, Moher D, Reeves BC, Shea B, Loke Y, Garner S, et al. Issues relating to selective reporting when including non-randomized studies in systematic reviews on the effects of healthcare interventions. Res Synth Methods. 2013;4:36–47.CrossRefPubMed
72.
Munn Z, Moola S, Lisy K, Riitano D, Tufanaru C. Methodological guidance for systematic reivews of observational epidemiological studies reporting prevalence and cumulative incidence data. Int J Evid Based Healthc. 2015;13:147–53.CrossRefPubMed
73.
Zingg W, Castro-Sanchez E, Secci FV, Edwards R, Drumright LN, Sevdalis N, et al. Innovative tools for quality assessment: integrated quality criteria for review of multiple study designs (ICROMS). Public Health. 2016;133:19–37.CrossRefPubMed
74.
Horton J, Vandermeer B, Hartling L, Tjosvold L, Klassen TP, Buscemi N. Systematic review data extraction: cross-sectional study showed that experience did not increase accuracy. J Clin Epidemiol. 2010;63:289–98.CrossRefPubMed
75.
Valentine JC, Thompson SG. Issues relating to confounding and meta-analysis when including non-randomized studies in systematic reviews on the effects of interventions. Res Synth Methods. 2013;4:26–35.CrossRefPubMed
76.
Austin H, Perkins LL, Martin DO. Estimating a relative risk across sparse case-control and follow-up studies: a method for meta-analysis. Stat Med. 1997;16:1005–15.CrossRefPubMed
77.
Colditz GA, Burdick E, Mosteller F. Heterogeneity in meta-analysis of data from epidemiologic studies: a commentary. Am J Epidemiol. 1995;142:371–82.CrossRefPubMed
78.
Sutton AJ, Cooper NJ, Lambert PC, Jones DR, Abrams KR, Sweeting MJ. Meta-analysis of rare and adverse event data. Expert Rev Pharmacoecon Outcomes Res. 2002;2:367–79.CrossRefPubMed
79.
Martin DO, Austin H. An exact method for meta-analysis of case-control and follow-up studies. Epidemiology. 2000;11:255–60.CrossRefPubMed
80.
Moreno V, Martin ML, Bosch FX, de Sanjose S, Torres F, Munoz N. Combined analysis of matched and unmatched case-control studies: comparison of risk estimates from different studies. Am J Epidemiol. 1996;143:293–300.CrossRefPubMed
81.
Souverein OW, Dullemeijer C, van’t Veer P, van der Voet H. Transformations of summary statistics as input in meta-analysis for linear dose-response models on a logarithmic scale: a methodology developed within EURRECA. BMC Med Res Methodol. 2012;12:57.CrossRefPubMedPubMedCentral
82.
Sterne JA, Hernán MA, Reeves BC, Savović J, Berkman ND, Viswanathan M, et al. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions. BMJ. 2016;355:i4919.CrossRefPubMedPubMedCentral
83.
Verde PE, Ohmann C. Combining randomized and nonrandomized evidence in clinical research: a review of methods and applications. Res Synth Methods. 2015;6:45–62.CrossRefPubMed
84.
Balshem H, Helfand M, Schunemann HJ, Oxman AD, Kunz R, Brozek J, et al. GRADE guidelines: 3. Rating the quality of evidence. J Clin Epidemiol. 2011;64:401–6.CrossRefPubMed
85.
Greenland S. Invited commentary: a critical look at some popular meta-analytic methods. Am J Epidemiol. 1994;140:290–6.CrossRefPubMed
86.
Wong WC, Cheung CS, Hart GJ. Development of a quality assessment tool for systematic reviews of observational studies (QATSO) of HIV prevalence in men having sex with men and associated risk behaviours. Emerg Themes Epidemiol. 2008;5:23.CrossRefPubMedPubMedCentral
87.
Salanti G, Sanderson S, Higgins JP. Obstacles and opportunities in meta-analysis of genetic association studies. Genet Med. 2005;7:13–20.CrossRefPubMed
88.
Ioannidis JP. Commentary: adjusting for bias: a user’s guide to performing plastic surgery on meta-analyses of observational studies. Int J Epidemiol. 2011;40:777–9.CrossRefPubMed
89.
Shamliyan T, Kane RL, Jansen S. Systematic reviews synthesized evidence without consistent quality assessment of primary studies examining epidemiology of chronic diseases. J Clin Epidemiol. 2012;65:610–8.CrossRefPubMed
90.
Sanderson S, Tatt ID, Higgins JP. Tools for assessing quality and susceptibility to bias in observational studies in epidemiology: a systematic review and annotated bibliography. Int J Epidemiol. 2007;36:666–76.CrossRefPubMed
91.
West S, King V, Carey TS, Lohr KN, McKoy N, Sutton SF, et al. Systems to rate the strength of scientific evidence. Evid Rep Technol Assess (Summ). 2002:1–11.
92.
Herbison P, Hay-Smith J, Gillespie WJ. Adjustment of meta-analyses on the basis of quality scores should be abandoned. J Clin Epidemiol. 2006;59:1249–56.CrossRefPubMed
93.
Guyatt GH, Oxman AD, Vist G, Kunz R, Brozek J, Alonso-Coello P, et al. GRADE guidelines: 4. Rating the quality of evidence - study limitations (risk of bias). J Clin Epidemiol. 2011;64:407–15.CrossRefPubMed
94.
Robertson C, Ramsay C, Gurung T, Mowatt G, Pickard R, Sharma P. Practicalities of using a modified version of the Cochrane collaboration risk of bias tool for randomised and non-randomised study designs applied in a health technology assessment setting. Res Synth Methods. 2014;5:200–11.CrossRefPubMed
95.
Guyatt GH, Oxman AD, Montori V, Vist G, Kunz R, Brozek J, et al. GRADE guidelines: 5. Rating the quality of evidence -publication bias. J Clin Epidemiol. 2011;64:1277–82.CrossRefPubMed
96.
97.
98.
99.
Sutton AJ, Abrams KR, Jones DR. Generalized synthesis of evidence and the threat of dissemination bias. The example of electronic fetal heart rate monitoring (EFM). J Clin Epidemiol. 2002;55:1013–24.CrossRefPubMed
100.
Pladevall-Vila M, Delclos GL, Varas C, Guyer H, Brugues-Tarradellas J, Anglada-Arisa A. Controversy of oral contraceptives and risk of rheumatoid arthritis: meta-analysis of conflicting studies and review of conflicting meta-analyses with special emphasis on analysis of heterogeneity. Am J Epidemiol. 1996;144:1–14.CrossRefPubMed
101.
Dwyer T, Couper D, Walter SD. Sources of heterogeneity in the meta-analysis of observational studies: the example of SIDS and sleeping position. J Clin Epidemiol. 2001;54:440–7.CrossRefPubMed
102.
Abrams K, Jones DR. Meta-analysis and the synthesis of evidence. IMA J Math Appl Med Biol. 1995;12:297–313.CrossRefPubMed
103.
Doria AS. Meta-analysis and structured literature review in radiology. Acad Radiol. 2005;12:399–408.CrossRefPubMed
104.
Takkouche B, Cadarso-Suarez C, Spiegelman D. Evaluation of old and new tests of heterogeneity in epidemiologic meta-analysis. Am J Epidemiol. 1999;150:206–15.CrossRefPubMed
105.
Zeegers MP, Heisterkamp SH, Kostense PJ, van der Windt DA, Scholten RJ. Practice of systematic reviews. VII. Pooling of results from observational studies. Ned Tijdschr Geneeskd. 2000;144:1393–7.PubMed
106.
Guyatt GH, Oxman AD, Kunz R, Woodcock J, Brozek J, Helfand M, et al. GRADE guidelines: 7. Rating the quality of evidence - inconsistency. J Clin Epidemiol. 2011;64:1294–302.CrossRefPubMed
107.
Hernandez AF, Gonzalez-Alzaga B, Lopez-Flores I, Lacasana M. Systematic reviews on neurodevelopmental and neurodegenerative disorders linked to pesticide exposure: methodological features and impact on risk assessment. Environ Int. 2016;92–93:657–79.CrossRefPubMed
108.
Weeks DL. The regression effect as a neglected source of bias in nonrandomized intervention trials and systematic reviews of observational studies. Eval Health Prof. 2007;30:254–65.CrossRefPubMed
109.
Hartemink N, Boshuizen HC, Nagelkerke NJ, Jacobs MA, van Houwelingen HC. Combining risk estimates from observational studies with different exposure cutpoints: a meta-analysis on body mass index and diabetes type 2. Am J Epidemiol. 2006;163:1042–52.CrossRefPubMed
110.
Salanti G, Ioannidis JP. Synthesis of observational studies should consider credibility ceilings. J Clin Epidemiol. 2009;62:115–22.CrossRefPubMed
111.
Smith SJ, Caudill SP, Steinberg KK, Thacker SB. On combining dose-response data from epidemiological studies by meta-analysis. Stat Med. 1995;14:531–44.CrossRefPubMed
112.
Thompson S, Ekelund U, Jebb S, Lindroos AK, Mander A, Sharp S, et al. A proposed method of bias adjustment for meta-analyses of published observational studies. Int J Epidemiol. 2011;40:765–77.CrossRefPubMed
113.
Tweedie RL, Mengersen KL. Meta-analytic approaches to dose-response relationships, with application in studies of lung cancer and exposure to environmental tobacco smoke. Stat Med. 1995;14:545–69.CrossRefPubMed
114.
McCarron CE, Pullenayegum EM, Thabane L, Goeree R, Tarride JE. The importance of adjusting for potential confounders in Bayesian hierarchical models synthesising evidence from randomised and non-randomised studies: an application comparing treatments for abdominal aortic aneurysms. BMC Med Res Methodol. 2010;10:64.CrossRefPubMedPubMedCentral
115.
Thompson SG, Higgins JP. How should meta-regression analyses be undertaken and interpreted? Stat Med. 2002;21:1559–73.CrossRefPubMed
116.
Brockwell SE, Gordon IR. A comparison of statistical methods for meta-analysis. Stat Med. 2001;20:825–40.CrossRefPubMed
117.
Prevost TC, Abrams KR, Jones DR. Hierarchical models in generalized synthesis of evidence: an example based on studies of breast cancer screening. Stat Med. 2000;19:3359–76.CrossRefPubMed
118.
Shuster JJ, Jones LS, Salmon DA. Fixed vs random effects meta-analysis in rare event studies: the rosiglitazone link with myocardial infarction and cardiac death. Stat Med. 2007;26:4375–85.CrossRefPubMed
Metadata
Title
Methods to systematically review and meta-analyse observational studies: a systematic scoping review of recommendations
Authors
Monika Mueller
Maddalena D’Addario
Matthias Egger
Myriam Cevallos
Olaf Dekkers
Catrina Mugglin
Pippa Scott
Publication date
01-12-2018
Publisher
BioMed Central
Published in
BMC Medical Research Methodology / Issue 1/2018
Electronic ISSN: 1471-2288
DOI
https://doi.org/10.1186/s12874-018-0495-9

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