Randomised trials in surgery: problems and possible solutions

McCulloch, Peter; Taylor, I.; Sasako, Mitsuru; Lovett, Bryony; Griffin, Damian R.

doi:10.1136/bmj.324.7351.1448

Cited by 673 publications

(510 citation statements)

References 33 publications

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“…Thus, confounding may still pose a major threat to the validity of findings despite best efforts and should be included in the analysis of results. Given the problematic nature of sample sizes in surgical and orthopaedic research, this post hoc quality control becomes even more important [5,8,9]. This can be done either by stratification of the data by suspected variables or by multivariate analysis, usually using regression models.…”

Section: Discussionmentioning

confidence: 99%

Management of Confounding in Controlled Orthopaedic Trials

Vavken

Culen

Dorotka

2008

Clinical Orthopaedics &Amp; Related Research

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Confounding occurs when the effect of an exposure on an outcome is distorted by a confounding factor and will lead to spurious effect estimates in clinical studies. Although confounding can be minimized at the design stage, residual confounding may remain. An argument therefore can be made for controlling for confounding during data analysis in all studies. We asked whether confounding is considered in controlled trials in orthopaedic research and hypothesized the likelihood of doing so is affected by participation of a scientifically trained individual and associated with the magnitude of the impact factor. We performed a cross-sectional study of all controlled trials published in 2006 in eight orthopaedic journals with a high impact factor. In 126 controlled studies, 20 (15.9%; 95% confidence interval, 9.5%-22.3%) studies discussed confounding without adjusting in the analysis. Thirty-eight (30.2%; 95% confidence interval, 22.2%-38.2%) controlled for confounding, although we suspect the true proportion might be somewhat higher. Participation of a methodologically trained researcher was associated with (odds ratio, 3.85) controlling for confounding, although there was no association between impact factor and controlling for confounding. The question remains to what extent the validity of published findings is affected by failure to control for confounding.

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Section: Discussionmentioning

confidence: 99%

Management of Confounding in Controlled Orthopaedic Trials

Vavken

Culen

Dorotka

2008

Clinical Orthopaedics &Amp; Related Research

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“…12 Patient-related factors have been identified to explain this, such as a lack of understanding about research or medical condition; concerns with the research process, especially randomisation; preference for particular treatments; and a perception that research is inappropriate for serious medical conditions. 16,20,21 In clinical trials of surgical procedures, these issues are more pronounced, 22 especially where surgical interventions are being compared with medical treatment. 23 Understanding the attitudes, beliefs, and insights of potential trial subjects can be helpful in recognising barriers to trial recruitment, and can be used to inform strategies to overcome these.…”

Section: Introductionmentioning

confidence: 99%

The willingness of patients presenting with advanced glaucoma to participate in a trial comparing primary medical vs primary surgical treatment

Leighton

Lonsdale

Tildsley

et al. 2011

Eye

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Aim The aim of this study is to examine the attitudes of patients, who presented with advanced glaucoma in at least one eye, to participation in a randomised prospective trial comparing primary medical treatment with primary surgical treatment for advanced glaucoma. Methods Patients who had presented with advanced glaucoma (415 dB loss mean deviation on Humphrey visual field testing) in at least one eye were asked to participate. Five focus groups comprising of 4-8 patients and consisting of 29 patients in total were undertaken. The group interviews were conducted by two experienced qualitative researchers, an ophthalmic clinician was present to clarify technical issues. The focus group discussions were taped and transcribed in full, and analysed through a process of familiarisation, open (inductive) coding, theme generation, theme refinement, and thematic mapping. Results Three overarching themes were identified: (1) the extent of patients' knowledge, (2) anxieties about surgery, and (3) concerns about compromised care due to trial involvement; these themes were further classified into eight sub-themes. Conclusions Patients' willingness to participate in randomised clinical studies is significantly connected to their level of comprehension and insight about the medical condition, its treatment, and the research process; misunderstandings about any of these aspects may act as a significant barrier to trial recruitment. Recruitment rates for future randomised trials may be enhanced by ensuring that patients have full and accurate information about the treatment alternatives, and that uncertainty exists for best patient outcomes between treatment options, and reassuring potential participants that the research process, in particular randomisation, will not compromise clinical care.

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“…We also have the problem of masking, because numerous interventions are performed on the patient directly by the clinic or the surgeon (for example, in an investigation that involves a wound or scar, we could only compare surgical techniques performed in a similar fashion or by a more or less common access, otherwise in order for the one receiving or measuring the effect of the therapy to remain masked, we would have to inflict a wound similar to those of the study group on patients from the control group, which would be ethically unacceptable); in the field of surgery, we know that interventions are "operatordependant": that there are therefore greater ethical controversies in assigning a random allocation and, finally, because the training period directly influences results (Lee et al, 2000;Horton, 1996;McCulloch et al, 2002).…”

Section: Discussionmentioning

confidence: 99%

Systematic Review of Literature with Different Types of Designs

et al. 2009

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SUMMARY:In certain situations, which occur with particular frequency in the field of surgery and its related disciplines (where what predominates are observational-type studies), the management of randomized controlled clinical trials (RCT) is very difficult and as such, conducting a systematic review (SR) based on RCT and realice a meta-analysis is even more difficult. Therefore, we have generated a methodology for implementing a SR with different types of designs (including observational studies) as an alternative in order to clarify the uncertainty in the field of therapy when there are few RCT and the evidence relies so heavily on descriptive and observational studies. The aim of this study, was to set out a methodology that leads to a SR with various types of designs. Methodologycally, this is based on consideration of the different primary studies through the application of a methodological quality score made up of 3 items (type of study design, size of the population studied and methodology used in the study). Once assigned a point score, a calculation of weighted averages with their respective confidence intervals of 95% is applied to each variable to be studied, which finally enables to apply a metaanalysis and compare groups. A methodological proposal leading to a SR with various types of designs.

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Randomised trials in surgery: problems and possible solutions

Cited by 673 publications

References 33 publications

Management of Confounding in Controlled Orthopaedic Trials

Management of Confounding in Controlled Orthopaedic Trials

The willingness of patients presenting with advanced glaucoma to participate in a trial comparing primary medical vs primary surgical treatment

Systematic Review of Literature with Different Types of Designs

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