Reporting of key methodological issues in placebo-controlled trials of surgery needs improvement: a systematic review

Sian Cousins; Natalie S Blencowe; Carmen Tsang; Ava Lorenc; Katy Chalmers; Andrew J Carr; Marion K Campbell; Jonathan A Cook; David J Beard; Jane M Blazeby

doi:10.1016/j.jclinepi.2019.11.016

Reporting of key methodological issues in placebo-controlled trials of surgery needs improvement: a systematic review

J Clin Epidemiol. 2020 Mar:119:109-116. doi: 10.1016/j.jclinepi.2019.11.016. Epub 2019 Nov 28.

Authors

Affiliations

¹ National Institute of Health Research (NIHR), Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol, Surgical Innovation theme and the Medical Research Council ConDuCT-II Hub for Trials Methodology Research, Bristol Centre for Surgical Research, Population Health Sciences, Bristol Medical School, Bristol, UK. Electronic address: Sian.cousins@bristol.ac.uk.
² National Institute of Health Research (NIHR), Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol, Surgical Innovation theme and the Medical Research Council ConDuCT-II Hub for Trials Methodology Research, Bristol Centre for Surgical Research, Population Health Sciences, Bristol Medical School, Bristol, UK; Division of Surgery, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
³ National Institute of Health Research (NIHR), Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol, Surgical Innovation theme and the Medical Research Council ConDuCT-II Hub for Trials Methodology Research, Bristol Centre for Surgical Research, Population Health Sciences, Bristol Medical School, Bristol, UK.
⁴ Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Headington, Oxford, UK; National Institute of Health Research (NIHR) Biomedical Research Centre, Oxford University Hospitals NHS Foundation Trust, Oxford, UK; Royal College of Surgeons (England) Surgical Interventional Trials Unit (SITU), Botnar Research Centre, University of Oxford, Headington, Oxford, UK.
⁵ Health Services Research Unit, University of Aberdeen, Aberdeen, UK.

Abstract

Objectives: To examine key methodological considerations for using a placebo intervention in randomized controlled trials (RCTs) evaluating invasive procedures, including surgery.

Study design and setting: RCTs comparing an invasive procedure with a placebo were included in this systematic review. Articles published from database inception to December 31, 2017, were retrieved from Ovid MEDLINE, Ovid EMBASE and CENTRAL electronic databases, by handsearching references and expert knowledge. Data on trial characteristics (clinical area, nature of invasive procedure, number of patients and centers) and key methodological (rationale for using placebos, minimization of risk, information provision, offering the treatment intervention to patients randomized to placebo, delivery of cointerventions, and intervention standardization and fidelity) were extracted and summarized descriptively.

Results: One hundred thirteen articles reporting 96 RCTs were identified. Most were conducted in gastrointestinal surgery (n = 40, 42%) and evaluated minimally invasive procedures (n = 44, 46%). Over two-thirds randomized fewer than 100 patients (n = 65, 68%) and a third were single center (n = 31, 32%). A third (n = 33, 34%) did not report a rationale for using a placebo. Most common strategies to minimize patient risk were operator skill (n = 22, 23%) and independent data monitoring (n = 28, 29%). Provision of patient information regarding placebo use was infrequently reported (n = 11, 11%). Treatment interventions were offered to patients randomized to placebo in 43 trials (45%). Cointerventions were inconsistently reported, but 64 trials (67%) stated that anesthesia was matched between groups. Attempts to standardize interventions and monitor their delivery were reported in n = 7, (7%) and n = 4, (4%) trials, respectively.

Conclusion: Most placebo-controlled trials in surgery evaluate minor surgical procedures and currently there is inconsistent reporting of key trial methods. There is a need for guidance to optimize the transparency of trial reporting in this area.

Keywords: Invasive procedures; Methodology; Placebo surgery; Surgery; Systematic review.

Publication types

Research Support, Non-U.S. Gov't
Systematic Review

MeSH terms

Data Collection / methods*
Humans
Placebos
Quality Improvement*
Randomized Controlled Trials as Topic / methods*
Research Design*
Surgical Procedures, Operative / methods*

Substances

Placebos

Abstract

Publication types

MeSH terms

Substances

Grants and funding