How we grade
The grade measures the strength of the published evidence that a tool works in patient care, not the quality of the product. A low grade can mean the studies have not been done.
Each review sets out what the tool does, who uses it, how the Food and Drug Administration (FDA) treats it and what published studies found, then gives an evidence grade from A to D and, where a credible independent study found poor real-world performance, a safety problem or harm, a caution flag. Every fact links to its source.
The grades
- Grade A
- Randomized evidence of benefit. Randomized controlled trials of the tool in routine care, published in peer-reviewed journals, met their primary outcome and found a benefit to patients or to care, such as more diagnoses made, fewer unnecessary procedures, better outcomes, or less clinician time or burden. Where such trials disagree, most of them did.
- Grade B
- Evidence from clinical use. Studies have measured what happens when the tool is used in patients' care, such as its effect on diagnoses, decisions, workflow or outcomes, but randomized trials have not shown a consistent benefit, either because there are none or because their results are mixed or null.
- Grade C
- Accuracy studies only. Studies measure only how accurate the tool is, in retrospective or prospective accuracy studies, test sets, simulated cases or reader studies, including the data behind an FDA clearance; none has measured its effect on care.
- Grade D
- Little or no independent evidence. The published evidence comes only from the company, in its own studies, claims, white papers, case reports or press releases, with no FDA review of its data.
The caution flag
Caution Caution is a separate flag, shown with any grade, for a credible independent study that found poor real-world performance, a safety problem or harm, such as accuracy far below the company's own figures.
Which studies count
When a review covers several products or modules, the grade is for the one named beside it, and the review says how the others stand. A study counts for a tool if it tested that company's product, under its current or an earlier name or version, or an algorithm that the company, FDA or the algorithm's developers document as the one in the product or an earlier version of it; a predecessor developed separately does not count.
The key study
Key study: the largest randomized trial published in a journal; if there is none, the largest study of the tool in clinical use; if none, its main accuracy study.
Grades now
Grades now: A 8, B 47, C 39, D 5. Caution flags: 20.
About these reviews
FDA status is listed separately and is not evidence of benefit. A 510(k) clearance means FDA found a device substantially equivalent to one already legally marketed, and a De Novo authorization classifies a novel device that has no such predicate; neither is a finding that the device improves care.
The tools were chosen because they are widely used, widely marketed to physicians or widely studied, with one to 11 in each category. The reviews draw on peer-reviewed studies, preprints (labeled as such), FDA records, health technology assessments, news and institutional reports, and company pages; company statements are attributed and are not counted as evidence that a tool works. No company paid for, saw or approved its review before publication. The reviews are not medical advice or an endorsement of any product, and each shows the date it was last checked.
The evidence is current to Oct. 7, 2026. Corrections and new studies can be sent through the contact form.
Reviews of the published evidence, not medical advice or an endorsement of any product.