Randomized clinical trials of the impact of alternative diagnostic strategies on patient-important outcomes: a systematic survey

Oral
2015 Vienna
El Dib R1, Tikinnen K2, Akl E3, Mustafa RA4, Agarwal A5, Gomaa HA6, Carpenter CR7, Zhang Y8, Nascimento Jr P9, Jorge EC9, Almeida RA9, Doles JVP9, Mustafa AA10, Sadeghirad B11, Lopes LC12, Bergamaschi CC12, Suzumura EA13, Cardoso MM9, Stone SB14, Schünemann HJ15, Guyatt GH15
1Botucatu Medical School, Unesp, Universidade Estadual Paulista, Brazil
2Helsinki University Central Hospital and University of Helsinki, Finland
3American University of Beirut, Lebanon
4University of Missouri-Kansas City, Missouri, USA
5University of Toronto, Canada
6Tanta University, Egypt
7 Washington University in St Louis, USA
8Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada
9Botucatu Medical School - Unesp - Universidade Estadual Paulista, Brazil
10Jordan University of Science and Technology, Erbid, Jordan
11 Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada
12University of Sorocaba, Sao Paulo, Brazil
13Hospital do Coração - HCor, São Paulo, Brazil
14 Northern Ontario School of Medicine, Canada
15 Department of Clinical Epidemiology and Biostatistics, McMaster University, Canada

Background:

Diagnostic tests represent a pivotal part of patient management. Often clinicians adopt tests for clinical use on the basis of findings of diagnostic accuracy. Although in some instances simply knowing accuracy can allow inferences of patient benefit, in many others the use even of accurate tests may not improve outcomes important to patients. The latter situations require randomized trials of alternative diagnostic strategies to establish benefit.

Objectives:

To provide a perspective on the current practice of randomized trials of diagnostic strategies, focusing on outcomes important to patients.

Methods:

We included randomized controlled trials (RCTs) published in full-text reports that evaluated alternative diagnostic strategies.

Results:

We included 130 eligible RCTs from 56,912 unique citations. These trials reported on: morbidities (n = 102; 78.5%); mortality (n = 53; 40.8%); and on symptoms/quality of life/functional status (n = 50; 38.5%). The number and percentage of the RCTs classified as low risk of bias were: generation of allocation (n = 66; 50.7%); allocation concealment (n = 44; 33.8%); blinding (n = 28; 21.5%); missing outcome data (n = 74; 56.9%); selective reporting (n = 44; 33.8%) and; free of other problems (n = 37; 28.4%). Of the 130 RCTs, 44 evaluated mortality; two reported statistically significant results, but neither provided an estimate of relative effect; 28 did not report whether the results were statistically significant and 14 of them reported a non-statistically significant results. Investigators reported the impact of morbidity in 75 RCTs: 16 reported statistically significant results, two of which reported a risk ratio (RR) less than 0.8 and two reported a RR greater than 1.0 – the remaining 14 did not report RRs; 32 did not report whether the results were statistically significant and 27 reported a non-statistically significant results.

Conclusions:

Randomized trials of diagnostic tests are not rare, seldom show clear benefits on patient-important outcomes, and often suffer from limitations in reporting and conduct.