Ninewells Hospital and Medical School, University of Dundee, James Arrott Drive, Dundee, DD2 1SY, Scotland.
Population Health and Genomics Division, University of Dundee, Mackenzie Building, Kirsty Semple Way, Dundee, DD2 4BF, Scotland.
Trials. 2020 Feb 26;21(1):228. doi: 10.1186/s13063-020-4139-0.
The generalisability of randomized controlled trials (RCTs) can be uncertain because the impact of exclusion criteria is rarely quantified. The aim of this study was to systematically review studies examining the percentage of clinical populations with a physical health condition who would be excluded by RCTs of treatments for that condition.
Medline and Embase were searched from inception to Feb 11th 2018. Two reviewers independently completed screening, full-text review, data extraction and risk-of-bias assessment. The primary outcome was the percentage of patients in the clinical population who would have been excluded from each examined trial. Subgroup analyses examined exclusion by population setting, publication date and funding source.
Titles/abstracts (20,754) were screened, and 50 studies were included which reported exclusion rates from 305 trials of treatments in 31 physical conditions. Estimated rates of exclusion from trials varied from 0% to 100%, and the median exclusion rate was 77.1% of patients (interquartile range 55.5% to 89.0% exclusion). Median exclusion rates for trials in common chronic conditions were high, including hypertension 83.0%, type 2 diabetes 81.7%, chronic obstructive pulmonary disease 84.3%, and asthma 96.0%. The most commonly applied exclusion criteria related to age, co-morbidity and co-prescribing, whereas more implicit criteria relating to life expectancy or functional status were not typically examined. There was no evidence that exclusion varied by the nature of the clinical population in which exclusion was evaluated or trial funding source. There was no statistically significant change in exclusion rates in more recent compared with older trials.
The majority of trials of treatments for physical conditions examined excluded the majority of patients with the condition being treated. Almost a quarter of the trials studied excluded over 90% of patients, more than half of trials excluded at least three quarters of patients, and four out of five trials excluded at least half of patients. A limitation is that most studies applied only a subset of eligibility criteria, so exclusion rates are likely under-estimated. Exclusion from trials of older people and people with co-morbidity and co-prescribing is increasingly untenable given population aging and increasing multimorbidity.
PROSPERO registration CRD42016042282.
随机对照试验（RCT）的普遍性可能存在不确定性，因为排除标准的影响很少被量化。本研究的目的是系统地回顾检查治疗某种疾病的 RCT 中，有多少患有该疾病的临床人群会被排除在外的研究。
从建库至 2018 年 2 月 11 日，检索 Medline 和 Embase。两名审查员独立完成筛选、全文审查、数据提取和偏倚风险评估。主要结局指标是每个被检查试验中被排除的临床人群患者的百分比。亚组分析考察了人群设置、发表日期和资金来源对排除的影响。
筛选出标题/摘要（20754 篇），纳入了 50 项研究，这些研究报告了 31 种身体状况的 305 项治疗试验的排除率。试验排除率从 0%到 100%不等，中位数排除率为 77.1%的患者（四分位间距 55.5%至 89.0%排除）。常见慢性病的试验排除率较高，包括高血压 83.0%、2 型糖尿病 81.7%、慢性阻塞性肺疾病 84.3%和哮喘 96.0%。最常应用的排除标准与年龄、合并症和共用药有关，而与预期寿命或功能状态有关的更隐性的标准则通常未被检查。没有证据表明排除率因评估排除的临床人群的性质或试验资金来源而有所不同。与较老的试验相比，最近的试验中排除率没有统计学上的显著变化。
大多数检查治疗身体状况的 RCT 排除了大多数患有所治疗疾病的患者。近四分之一的研究排除了超过 90%的患者，超过一半的研究排除了至少四分之三的患者，五分之四的研究排除了至少一半的患者。一个限制是，大多数研究仅应用了一部分资格标准，因此排除率可能被低估了。鉴于人口老龄化和日益增加的合并症，对老年人和患有合并症和共用药的人的试验排除越来越不可行。
PROSPERO 注册 CRD42016042282。
