St George and Sutherland Clinical Campuses, School of Clinical Medicine, UNSW Medicine & Health, Sydney, New South Wales, Australia
St George and Sutherland Clinical Campuses, School of Clinical Medicine, UNSW Medicine & Health, Sydney, New South Wales, Australia.
BMJ Open. 2024 Apr 18;14(4):e080258. doi: 10.1136/bmjopen-2023-080258.
To compare differences in recruitment and attrition between placebo control randomised trials of surgery, and trials of the same surgical interventions and conditions that used non-operative (non-placebo) controls.
Meta-epidemiological study.
Randomised controlled trials were identified from an electronic search of MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials from their inception date to 21 November 2018.
Placebo control trials evaluating efficacy of any surgical intervention and non-operative control trials of the same surgical intervention were included in this study. 25 730 records were retrieved from our systemic search, identifying 61 placebo control and 38 non-operative control trials for inclusion in analysis.
Primary outcome measures were recruitment and attrition. These were assessed in terms of recruitment rate (number of participants enrolled, as a proportion of those eligible) and overall attrition rate (composite of dropout, loss to follow-up and cross-overs, expressed as proportion of total sample size). Secondary outcome measures included participant cross-over rate, dropout and loss to follow-up.
Unadjusted pooled recruitment and attrition rates were similar between placebo and non-operative control trials. Study characteristics were not significantly different apart from time to primary timepoint which was shorter in studies with placebo controls (365 vs 274 days, p=0.006). After adjusting for covariates (follow-up duration and number of timepoints), the attrition rate of placebo control trials was almost twice as high compared with non-operative controlled-trials (incident rate ratio (IRR) (95% CI) 1.8 (1.1 to 3.0), p=0.032). The incorporation of one additional follow-up timepoint (regardless of follow-up duration) was associated with reduced attrition in placebo control surgical trials (IRR (95% CI) 0.64 (0.52 to 0.79), p<0.001).
Placebo control trials of surgery have similar recruitment issues but higher attrition compared with non-operative (non-placebo) control trials. Study design should incorporate strategies such as increased timepoints for given follow-up duration to mitigate losses to follow-up and dropout.
CRD42019117364.
比较手术安慰剂对照随机试验与相同手术干预和条件的非手术（非安慰剂）对照试验在招募和脱落方面的差异。
Meta 流行病学研究。
从 MEDLINE、EMBASE 和 Cochrane 对照试验中心注册库的起始日期到 2018 年 11 月 21 日，对随机对照试验进行了电子检索。
纳入评估任何手术干预疗效的安慰剂对照试验和相同手术干预的非手术对照试验。从系统搜索中检索到 25730 条记录，确定了 61 项安慰剂对照和 38 项非手术对照试验纳入分析。
主要结局指标是招募和脱落。以招募率（纳入的参与者人数，占合格人数的比例）和总体脱落率（脱落、失访和交叉的综合，以总样本量的比例表示）来评估。次要结局指标包括参与者交叉率、脱落和失访。
安慰剂对照试验和非手术对照试验的未调整 pooled 招募率和脱落率相似。除了安慰剂对照研究的主要时间点更短（365 天 vs 274 天，p=0.006）外，研究特征没有显著差异。调整随访时间和时间点数量等协变量后，安慰剂对照试验的脱落率几乎是非手术对照试验的两倍（发生率比（IRR）（95%CI）1.8（1.1 至 3.0），p=0.032）。在安慰剂对照外科试验中，每增加一个随访时间点（无论随访时间长短），脱落率均降低（IRR（95%CI）0.64（0.52 至 0.79），p<0.001）。
与非手术（非安慰剂）对照试验相比，手术安慰剂对照试验的招募问题相似，但脱落率更高。研究设计应纳入增加随访时间点等策略，以减少失访和脱落。
CRD42019117364。
