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Assessing The Quality Of Controlled Clinical Trials

P. Jüni, D. Altman, M. Egger
Published 2001 · Medicine

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This is the first in a series of four articles The quality of controlled trials is of obvious relevance to systematic reviews. If the “raw material” is flawed then the conclusions of systematic reviews cannot be trusted. Many reviewers formally assess the quality of primary trials by following the recommendations of the Cochrane Collaboration and other experts. 1 2 However, the methodology for both the assessment of quality and its incorporation into systematic reviews and meta-analysis are a matter of ongoing debate.3-5 In this article we discuss the concept of study quality and the methods used to assess quality. #### Components of internal and external validity of controlled clinical trials Internal validity —extent to which systematic error (bias) is minimised in clinical trials Quality is a multidimensional concept, which could relate to the design, conduct, and analysis of a trial, its clinical relevance, or quality of reporting.6 The validity of the findings generated by a study clearly is an important dimension of quality. In the 1950s the social scientist Campbell proposed a useful distinction between internal and external validity (see box below). 7 8 Internal validity implies that the differences observed between groups of patients allocated to different …
This paper references
10.1016/S0140-6736(94)91344-7
Science of urinary incontinence: Report of a Meeting of Physicians and Scientists, University College London
J. Malone-Lee (1994)
10.1136/bmj.319.7211.670
What is meant by intention to treat analysis? Survey of published randomised controlled trials
S. Hollis (1999)
Cochrane reviewers ’ handbook 4 . 0
DJ Cook (1999)
RANDOMISATION : ESSENTIAL FOR REDUCING BIAS
D. Altman (1991)
Systematic reviews in health care : meta-analysis in context
M. Egger (2001)
10.1001/JAMA.285.15.1996
Value of flow diagrams in reports of randomized controlled trials.
M. Egger (2001)
10.1016/S0895-4356(99)00048-7
Impact of study quality on outcome in placebo-controlled trials of homeopathy.
K. Linde (1999)
Handbook of research on teaching
M. C. Wittrock (1986)
10.1016/0197-2456(81)90056-8
A method for assessing the quality of a randomized control trial.
T. Chalmers (1981)
10.1016/S0140-6736(98)01085-X
Does quality of reports of randomised trials affect estimates of intervention efficacy reported in meta-analyses?
D. Moher (1998)
Garbage in -garbage out'? Assessment of the quality of controlled trials in meta-analyses published in leading journals
P Jüni (2000)
10.1016/0895-4356(94)00172-M
Methodologic guidelines for systematic reviews of randomized control trials in health care from the Potsdam Consultation on Meta-Analysis.
D. Cook (1995)
10.1161/01.CIR.64.4.669
The randomized clinical trial: bias in analysis.
G. May (1981)
10.1016/0895-4356(94)00110-C
Meta-analysis: statistical alchemy for the 21st century.
A. Feinstein (1995)
10.1136/jech.51.4.354
Putting trials on trial--the costs and consequences of small trials in depression: a systematic review of methodology.
M. Hotopf (1997)
10.1016/S0140-6736(96)01201-9
Randomised trials, human nature, and reporting guidelines
K. Schulz (1996)
10.1016/S0140-6736(98)08127-6
Antihypertensive drugs in very old people: a subgroup meta-analysis of randomised controlled trials
F. Gueyffier (1999)
10.1136/bmj.323.7304.101
Investigating and dealing with publication and other biases in meta-analysis
J. Sterne (2001)
Cochrane reviewers' handbook 4.0
(1999)
Influence of adherence to treatment and response of cholesterol on mortality in the CDP
GS May (1980)
10.1001/JAMA.1995.03530180050029
Subverting randomization in controlled trials.
K. Schulz (1995)
10.1200/JCO.1986.4.6.942
A quality assessment of randomized control trials of primary treatment of breast cancer.
A. Liberati (1986)
10.1016/S0140-6736(05)62095-8
Slip-ups in diagnosis of subarachnoid haemorrhage
J. Gijn (1997)
10.1001/JAMA.285.15.1992
Use of the CONSORT statement and quality of reports of randomized trials: a comparative before-and-after evaluation.
D. Moher (2001)
Indications for fibrinolytic therapy in suspected acute myocardial infarction : collaborative overview of early mortality and major morbidity results from all randomised trials of more than 1000 patients
J. Herlitz (1994)
10.1177/096228029300200205
Controversies in meta-analysis: the case of the trials of serum cholesterol reduction
S. Thompson (1993)
Essential for reducing bias
D G Altman (1991)
10.1136/bmj.320.7237.737
Reducing errors made by emergency physicians in interpreting radiographs: longitudinal study
J. Espinosa (2000)
10.1001/JAMA.285.15.2000
Physician interpretations and textbook definitions of blinding terminology in randomized controlled trials.
P. Devereaux (2001)
10.1016/0895-4356(92)90085-2
Incorporating variations in the quality of individual randomized trials into meta-analysis.
A. Detsky (1992)
10.1016/0197-2456(94)00031-W
Assessing the quality of randomized controlled trials: an annotated bibliography of scales and checklists.
D. Moher (1995)
10.1016/0021-9150(78)90051-5
Coronary Drug Project Research Group.
L. Carlson (1978)
10.1001/ARCHOPHT.1967.00980030273002
Guilty until proved innocent.
H. Lincoff (1967)
Quality of randomised clinical trials affects estimates of intervention efficacy
L L Kjaergard (1999)
10.1136/pgmj.53.617.176
The Logic of Medicine
E. Murphy (1979)
Raw material
A. Sillitoe (1972)
10.1016/S0020-1383(98)00252-6
The association between seniority of Accident and Emergency doctor and outcome following trauma.
J. Wyatt (1999)
10.1001/JAMA.273.5.408
Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials.
K. Schulz (1995)
10.1056/NEJM197912273012602
Controversy in counting and attributing events in clinical trials.
D. Sackett (1979)
10.1037/H0040950
Factors relevant to the validity of experiments in social settings.
D. Campbell (1957)
10.1136/bmj.316.7132.673
Communication behaviours in a hospital setting: an observational study
E. Coiera (1998)
10.1136/bmj.316.7149.1922
Improving doctor-patient communication
S. Meryn (1998)
10.1001/JAMA.282.11.1054
The hazards of scoring the quality of clinical trials for meta-analysis.
P. Jüni (1999)
Influence of adherence to treatment and response of cholesterol on mortality in the CDP
(1980)
Assessing the quality of controlled clinical trials
M Egger (2001)
10.1212/WNL.44.1.16
The impact of blinding on the results of a randomized, placebo‐controlled multiple sclerosis clinical trial
J. Noseworthy (1994)
10.1093/OXFORDJOURNALS.AJE.A117250
Quality Scores Are Useless and Potentially Misleading: Reply to “Re: A Critical Look at Some Popular Analytic Methods”
S. Greenland (1994)
10.1016/S0140-6736(94)91161-4
Indications for fibrinolytic therapy in suspected acute myocardial infarction: collaborative overview of early mortality and major morbidity results from all randomised trials of more than 1000 patients
Fibrinolytic Therapy Trialists' Collaborative Group (1994)
10.1136/bmj.318.7192.1209
Treatment allocation in controlled trials: why randomise?
D. Altman (1999)
10.3310/HTA3120
Assessing the quality of reports of randomised trials: implications for the conduct of meta-analyses.
D. Moher (1999)
10.3109/00016349809004298
Amniotomy Or Oxytocin For Induction Of Labor: Re‐Analysis Of A Randomized Controlled Trial
M. Keirse (1988)
10.1001/JAMA.285.15.1987
The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomized trials.
D. Moher (2001)



This paper is referenced by
Genetic and psychological determinants of dyspepsia and implications for treatment
S. Mujakovic (2007)
Guidelines for Reporting Observational Studies
E. Elm (2007)
Is the routine use of antimicrobials useful for persistent diarrhoea in children under six in low and middle income countries
K. Abba (2007)
10.1007/s00464-013-3140-z
Fundoplication versus medical management of gastroesophageal reflux disease: systematic review and meta-analysis
Nadja Rickenbacher (2013)
10.1038/sj.ebd.6400710
Critically Appraising Systematic Reviews
Derek Richards (2010)
Test-treatment RCTs are susceptible to bias
Lavinia Ferrante di Ruffano (2017)
TaiChiExerciseforPatientsWithHeartDisease:A SystematicReviewofControlledClinicalTrials
Siu-man Ng (2012)
10.22159/ajpcr.2019.v12i12.35509
A META-ANALYSIS COMPARING THE EFFICACY AND SAFETY OF TERLIPRESSIN AND OCTREOTIDE IN THE MANAGEMENT OF ACUTE VARICEAL BLEEDING
Akanksha Mathur (2019)
10.1517/14712598.2011.560567
Direct autologous bone marrow-derived stem cell transplantation for ischemic heart disease: a meta-analysis
Y. Wen (2011)
Bahrain Medical Bulletin, Vol
M. Nasser (2008)
10.1111/j.1600-051X.2011.01783.x
Risk of bias of animal studies on regenerative procedures for periodontal and peri-implant bone defects - a systematic review.
C. Faggion (2011)
10.1159/000363595
Benefits and Risks of Breast Cancer Screening
A. Woeckel (2014)
10.1016/J.MEDCLI.2010.09.034
Declaración CONSORT 2010, actualización de la lista de comprobación para informar ensayos clínicos aleatorizados de grupos paralelos
A. Cobos-Carbó (2011)
10.1186/1471-2288-12-49
Method for appraising model validity of randomised controlled trials of homeopathic treatment: multi-rater concordance study
R. Mathie (2012)
Bone marrow-derived stem cells as an adjunctive treatment for acute myocardial infarction: a systematic review and meta-analysis.
R. A. T. Kuswardhani (2011)
10.1016/B978-0-7020-3137-3.00009-7
9 – Research methods, statistics and evidence-based practice
A. McIntosh (2010)
10.2515/THERAPIE/2013032
Essais cliniques institutionnels : quel monitoring ?
Catherine Cornu (2013)
10.1002/14651858.CD008818.pub2
Allogeneic hematopoietic cell transplantation for adult acute lymphoblastic leukemia (ALL) in first complete remission.
J. Pidala (2011)
10.1177/1077558713496318
Patient-Centered Approaches to Health Care
S. McMillan (2013)
10.1016/j.urology.2011.05.004
Placement of ureteral stent after uncomplicated ureteroscopy: do we really need it?
L. Tang (2011)
10.1002/EBCH.346
Commentary on ‘Parenting interventions for the prevention of unintentional injuries in childhood’
M. Cusimano (2009)
10.1002/EBCH.459
Cochrane review: Oral zinc for treating diarrhoea in children
M. Lazzerini (2009)
10.1002/14651858.CD003441.pub3
'As required' medication regimens for seriously mentally ill people in hospital.
P. Douglas-Hall (2015)
10.1001/JAMA.288.19.2408-JLT1120-4-3
Allocation Concealment in Clinical Trials—Reply
E. Balk (2002)
10.1159/000078343
The Implications of Different Approaches to Evaluating Intervention: Evidence from the Study of Language Delay/Disorder
J. Law (2004)
10.1111/j.1572-0241.2005.00327.x
The Journal Impact Factor as a Predictor of Trial Quality and Outcomes: Cohort Study of Hepatobiliary Randomized Clinical Trials
L. Gluud (2005)
10.2427/5937
Quality assessment in meta-analisys
G. Torre (2006)
10.1002/14651858.CD005350
Oral anticoagulants for the secondary prevention of coronary heart disease
G. Biondi-Zoccai (2005)
10.1002/14651858.CD008125.pub2
Sulpiride augmentation for schizophrenia.
J. Wang (2010)
10.1002/14651858.CD006617.pub3
Aripiprazole versus typical antipsychotic drugs for schizophrenia.
J. Bhattacharjee (2008)
10.1002/14651858.CD003625.PUB2
Interferon gamma for chronic hepatitis B
Nazir Ibrahim (2010)
10.1097/01.GIM.0000151839.12032.1A
Obstacles and opportunities in meta-analysis of genetic association studies
G. Salanti (2005)
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