Assessing the quality of randomization from reports of controlled trials published in obstetrics and gynecology journals

Schulz, Kenneth F.

doi:10.1001/jama.272.2.125

Cited by 151 publications

(134 citation statements)

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“…Studies similar to ours have been conducted in other specialties (3,(21)(22)(23)(24). These also show problems in the conduct and design of trials in other specialties.…”

Section: Discussionmentioning

confidence: 82%

“…The methodological quality of all these RCT was assessed by two independent assessors (GFMS, JC) using standard accepted quality of trial reporting indicators (allocation concealment, blinding, "intention-to-treat" analysis, completeness to follow-up). These were chosen because there is now strong empirical data showing that these items, if poorly reported, are generally associated with an over-estimation of treatment effect (2)(3)(4)(5)(6)(7)(8)(9)(10)(11). Disagreements in the quality assessment for these RCT were resolved by discussion and consensus among the two investigators (GS, JC).…”

Section: Quality Of Rct In Nephrologymentioning

confidence: 99%

“…Validity of RCT depends on the underlying methodological quality (1). Allocation concealment, blinding, intention-to-treat analysis, and loss to follow-up are the critical items in the design and conduct of RCT, and inadequately conceived and conducted RCT, like observational studies, may overestimate or underestimate true effects of interventions (2)(3)(4)(5)(6)(7)(8)(9)(10)(11).…”

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confidence: 99%

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The Number, Quality, and Coverage of Randomized Controlled Trials in Nephrology

Strippoli

Craig²,

Schena³

2004

Journal of the American Society of Nephrology

289

200

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Abstract. Randomized controlled trials (RCT) are the optimal study design to answer intervention questions. The authors evaluated the number, quality, and coverage of RCT in nephrology. MEDLINE was searched using the relevant medical subject headings for nephrology and 12 major specialties in internal medicine, limited by "randomized controlled trial" as a publication type. A random selection of 160 RCT in nephrology (40 for each decade) published since 1966 and an additional 270 RCT from ongoing or published Cochrane systematic reviews in various areas of nephrology, dialysis, and transplantation were evaluated for quality of reporting using standard criteria. The number of RCT published in nephrology from 1966 to 2002 (2779) is fewer than all other specialties of internal medicine (range: 5335 in hematology to 27109 in cardiology) with the proportion of all citations which are RCT being the third lowest (1.15%). There has been an increase in both indices from 1966 to 1996, but not at a greater rate than other specialties, and there has been no increase over the past 5 yr. Some areas of nephrology, in particular glomerulonephritis, are clear outliers with very low numbers of RCT to guide clinical decision-making. Overall the quality of RCT reporting in nephrology is low and has not improved over the past 30 yr with unclear allocation concealment (89%), lack of reported blinding of outcome assessors (92%), and failure to perform "intention-to-treat analysis" (50%) particularly frequent. The challenges of improving the quality and quantity of trials in nephrology are substantial, but they can be overcome by using standard guidelines and checklists for trial reporting, greater attention to the trial methods and not just the results, involving experts in trial design and reporting, multicenter collaboration, and larger and simpler trials.Because randomized controlled trials (RCT) are designed to provide unconfounded estimates of intervention effects, they are the ideal study type to answer intervention questions. However, not all RCT provide valid results. Validity of RCT depends on the underlying methodological quality (1). Allocation concealment, blinding, intention-to-treat analysis, and loss to follow-up are the critical items in the design and conduct of RCT, and inadequately conceived and conducted RCT, like observational studies, may overestimate or underestimate true effects of interventions (2-11).To our knowledge, there has never been a systematic evaluation of the number, coverage, and quality of RCT in nephrology. This was the aim of our study. If problems were identified, we also sought to propose feasible solutions. Materials and Methods Number and Proportion of RCT in Nephrology Compared with Other SpecialtiesThe medical subject heading (MESH) tree structure in MEDLINE (2002) was used to identify all major headings relevant to the primary specialties of internal medicine. Specifically, eight areas of internal medicine were searched by using the single broadest heading in the MeSH structure (cardiolog...

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“…Studies similar to ours have been conducted in other specialties (3,(21)(22)(23)(24). These also show problems in the conduct and design of trials in other specialties.…”

Section: Discussionmentioning

confidence: 82%

Section: Quality Of Rct In Nephrologymentioning

confidence: 99%

mentioning

confidence: 99%

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The Number, Quality, and Coverage of Randomized Controlled Trials in Nephrology

Strippoli

Craig²,

Schena³

2004

Journal of the American Society of Nephrology

289

200

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“…20,21 The researcher in charge of randomly assigning participants did not know in advance which treatment the next person would receive and did not participate in assessment. Assessment staff were blinded to participant randomisation assignment and participants were reminded not to discuss their randomisation assignments with assessment staff.…”

Section: Participant Retention and Adherencementioning

confidence: 99%

Resistance exercise training during pregnancy and newborn's birth size: a randomised controlled trial

2009

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Objective: We examined the effect of light intensity resistance exercise training performed during the second and third trimester of pregnancy on the newborn's birth size. We also studied the association between maternal body weight prior to pregnancy and newborn's birth size. Design: Randomised controlled trial. Subjects: We randomly assigned 160 sedentary gravidae to either a training (n ¼ 80) or a control (n ¼ 80) group. The training programme focused on light resistance and toning exercises (three times per week, 35-40 min per session). We recorded the Apgar score, birth weight, birth length, and head circumference of the newborn, as well as gestational age at time of delivery from hospital perinatal records. We also measured maternal weight and height before parity and gestational weight gain. Results: Maternal characteristics neither differed between groups (all P40.1) nor newborn characteristics (all P40.1). Maternal body weight was positively and significantly associated with newborn's birth weight and length only in the control group (b ¼ 19.20 and 0.065, respectively, Po0.01). Conclusion: Light intensity resistance training performed over the second and third trimester of pregnancy does not have a negative impact on the newborn's body size or overall health. Exercise interventions might attenuate the adverse consequences of maternal body weight before pregnancy on the newborn's birth size.

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“…This overlooks that while the randomised controlled trial is, in theory, a powerful method of determining which tested treatment has the greatest effect, there is more to validity than the investigators' description of randomisation and blinding. Not least are the worries about whether the randomisation and blinding were effective [64][65][66][67]. It is unusual for investigators to comment on their effectiveness but how else can readers, or systematic reviewers, know?…”

Section: Interpreting Meta-analysesmentioning

confidence: 99%

Anaesthesia and evidence‐based medicine

Goodman

1998

Anaesthesia

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Assessing the quality of randomization from reports of controlled trials published in obstetrics and gynecology journals

Cited by 151 publications

References 0 publications

The Number, Quality, and Coverage of Randomized Controlled Trials in Nephrology

The Number, Quality, and Coverage of Randomized Controlled Trials in Nephrology

Resistance exercise training during pregnancy and newborn's birth size: a randomised controlled trial

Anaesthesia and evidence‐based medicine

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