Table 1 Labels grouped by DTA-specificity
From: Use of test accuracy study design labels in NICE’s diagnostic guidance
Label | Interpretation | Similar/synonym labels |
|---|---|---|
1. DTA-specific labels (n = 19) | ||
1.1 DTA-informative (n = 6) | ||
Comparative performance | Comparison of minimum two index test/strategies [3]. | Comparative (diagnostic) accuracy studies |
Direct comparisons1 | Comparison of two index test/strategies within the same group/population (i.e. with the same set of eligibility criteria). | Head to head comparisons; within-study comparisons |
(Prospective cohort) randomized to either the index test or comparator2 | Randomization to either the index test or reference standard/comparator. | Randomized head-to-head comparisons |
(Prospective cohort) receiving the comparator and at least one index test with follow up3 | All participants receive both an index test and the reference standard/comparator and are followed up for a final outcome measure/status. | |
Reference standard positive studies | Only participants with a positive reference standard test receive the index test. | |
Single/two-gate diagnostic studies | Including one (single set of eligibility criteria) or two/multiple groups (separate sets of eligibility criteria) for comparison [9]. | Two-study cohorts |
1.2 DTA-descriptors (n = 9): | ||
Single/multi-centre study | Participants are sampled from a single or from multiple centres. | Large, multi-centre prospective (UK) study; two-centre |
Primary care study | Participants are sampled from settings in the primary (vs. secondary or tertiary) care. | |
Consecutive recruitment | Participants are sampled consecutively (vs. random or convenient sampling) [2]. | |
Symptomatic study | Including only symptomatic participants. | |
(Single-gate studies) recruiting populations at high risk | Including only high risk participants. | |
Population (-based) studies | Including/sampling participants that represent the target/study population [9]. | (Multi-centre) community-based study |
Pro- or retrospective studies | Data collection (or recruitment) was planned before (prospective study) the index test and reference standard were performed or after (retrospective study) (STARD) [7]. | Prospective cohort studies; prospective, consecutive cohort study; prospective, international multicentre |
Retrospective analysis (of prospective database) | Post-hoc or non-pre-specified statistical analysis. | |
Discordant case analysis4 | A study that excludes discordant cases in the analysis. | |
1.3 General DTA labels (n = 4) | ||
(Diagnostic) cohort studies | A diagnostic cohort study in which “individuals are enrolled before the final outcome (presence or absence of the target condition) is known” [9] (i.e. a single cohort/group of suspected participants). | (Retrospective) cohort studies |
(Diagnostic) case-control studies/design | “(…) studies in which the disease status is already known before the index test is performed”. “(…) the reference test is applied only to a subsample of the participants with or without the target condition”. [9] | |
(Diagnostic) cross-sectional studies | Comparison of the result of the index test with that of the reference standard in the same participant at the same time. [9] | |
(Diagnostic) observational studies | A DTA-study that only make use of observational data e.g. re-interpretation/review of existing tests results. | |
2. Umbrella terms (n = 4): | ||
Diagnostic accuracy studies | A study reporting diagnostic accuracy performance measures. | (Large prospective cohort) studies collecting diagnostic accuracy data |
End-to-end studies | A diagnostic accuracy study that directly links test results to patient outcomes (such as RCTs) [8]. | |
Long-term studies (following patients for several years) | A study that includes follow-up of any given outcome measure/status. | |
Pilot studies | A study that is testing/piloting a setting/feasibility, often with a small sample size. | |
3. Non-DTA-specific labels (n = 9) | ||
Test-treat trials | A study in which a test guides the treatment strategy. | |
Controlled clinical trials | A clinical trial including a control (comparator) group to the intervention group. | |
Cluster-randomized controlled trial | A study that randomizes clusters of participants to either intervention or control group. | |
Derivation study | A study that focuses on the development of a prediction model (contra validation of a model). | |
Observational studies | A study that only includes observational data (non-intervention data). | |
(Observational) cohort studies | A study using data from all cohort-members (in contrast to case-control study that uses data from an outcome-selected subset of the source population) [5, 10]. | |
Prospective, two cohorts (feasibility, validation) | A study with two separate cohorts recruited prospectively. | |
Randomized controlled trials (RCTs) | A study with randomization of participants to either intervention group(s) or a control (comparator) group (vs. non-randomized). | (Large multi-centre) RCT |
Validation study | A study that focuses on validation (of an existing/developed model). | |
4. Unclear labels (n = 3) | ||
Diagnostic studies with a control group | ||
(Multi-centre) tracker study | ||
Mixed design (of within-study comparisons) | ||