DT-1: Specify clinical context and key elements of the diagnostic test

A comparative evaluation of diagnostic tests should specify each of the following items and provide rationale in support of the particular choices:

1. the intended use of the test and the corresponding clinical context, including referral for additional testing, referral for additional treatments, and modification of current treatment and target populations;
2. the goal of the comparison;
3. the technical specifications of the tests as implemented in the study;
4. the approach to test interpretation;
5. the sources and process for obtaining reference standard information, when applicable;
6. the procedures for obtaining follow-up information and determining patient outcomes, when applicable; and
7. the clinical pathways involving the tests and the anticipated implications of test use on downstream processes of care and patient outcomes.

These items ought to be specified for all designs, including observational designs (e.g., those using medical records or registries). If these items are not available directly, validated approaches to approximating these study elements from available data should be used.

Public comments

The standard should differentiate between objective diagnostic and screening lab tests for biomarkers versus subjective assessment tools where an objective biomarker is not available for patient-reported outcomes (e.g. measurements of pain, depression, or anxiety).

Eli Lilly and Company , , 03/30/2016 - 2:27pm

DT-2: Assess the effect of factors known to affect diagnostic performance and outcomes

Studies of diagnostic tests should include an assessment of the effect of important factors known to affect test performance and outcomes, including the threshold for declaring a “positive” test result, the technical characteristics of the test and the interpreter, and the setting of care.

Public comments

Most studies of diagnostic tests evaluate only their accuracy, but further evidence is needed to determine a test’s true clinical value. Establishing benefit to patient health must be the priority for diagnostic evaluations. Test accuracy is one component of test evaluation, but does not capture the impact of tests on patients (Ruffano et al: Assessing the value of diagnostic tests: a framework for designing and evaluating trials. BMJ 2012). Therefore, PCORI should consider other components of test evaluation which are important to patients and consider including these aspects in revised standards. In addition, we recommend that PCORI consider discussing the significance of understanding the sensitivity and specificity of diagnostic tests and the importance of having this information readily available for medical personnel and patients alike.

Eli Lilly and Company , , 03/30/2016 - 2:27pm

DT-3: Focus studies of diagnostic tests on patient-centered outcomes, using rigorous study designs with preference for randomized controlled trials

Studies related to diagnostic and therapeutic outcomes of diagnostic testing should use a prospective randomized study design when possible. If a non-randomized design is proposed, a rationale for using an observational study (or modeling and simulation) should be provided, and efforts to minimize confounding documented.

Public comments

Why are randomized controlled trials "preferred"? Many patient - centered outcomes cannot be realistically addressed with randomized designs, and this section pushes the old logic that "when possible, always do a trial". For a document devoted to RWE and patient - centeredness, I don't think that this is the proper default position. {EBort}

{EBort}Merck & Co Inc, , 02/23/2016 - 2:39pm

General feedback on the Standards for Studies of Diagnostic Tests

Public comments

There have been a considerable amount of changes in the area of diagnostic tests since the last release of standards. Therefore, it critical that the new standards reflect this and clarify minimal expectations for researchers.

Eli Lilly and Company , , 03/30/2016 - 2:27pm