How to find clinical guidelines and studies

Evidence turns “my doctor says I need this” into “here is why the field agrees”. The plan’s reason for denying you tells you what kind of evidence to look for. Your doctor will usually know the key guidelines and studies already, so start there, then use this page to choose what to send and how to cite it.

What this means

Four kinds of evidence matter in most appeals:

Kind of evidence	What it shows	Who can help you find it
The plan’s own criteria	The standard the plan says you must meet	The plan, on request
A professional guideline	What experts in the field recommend for your diagnosis	Your doctor
A peer-reviewed study	What research found about the treatment	Your doctor
A regulatory approval	That the treatment is approved for a use	Your doctor or pharmacist

The fifth kind is your doctor’s own clinical experience with you, which belongs in the doctor’s letter.

Evidence supports your doctor. It does not replace the letter. You are not expected to judge the science yourself. If you are not sure whether a study fits your case, ask your doctor.

What to do

1. Start from the plan’s reason (your step). Write the reason in one sentence. “Not medically necessary”, “experimental”, “step therapy not met” and “not effective” each call for different evidence.
2. Get the plan’s criteria. See how to find the insurer’s medical policy. The best evidence answers the plan’s criteria point by point.
3. Ask your doctor (your step, then your doctor’s). Ask: “Which guidelines and studies support this treatment for my diagnosis? Can you name them in your letter?” The doctor’s letter should cite them, with title, source and year.
4. Search for more, if your doctor agrees. PubMed, a free search of medical journal articles, lets you look up a treatment and a diagnosis. Print or save the abstract (the short summary) or the page that supports your point.
5. Choose a few, not a pile. Pick two or three items that match your diagnosis, your treatment and the plan’s reason. A long stack hides the one page that matters.
6. Label what you send. Add a short note: “This guideline, page 4, recommends the treatment for patients who have already tried X.” Mark the line.
7. Look at past decisions. Some states publish independent review decisions. Washington’s insurance commissioner, for example, runs a public search of decisions since 2016, with the insurer, the diagnosis and treatment codes, the outcome and the reviewer’s reasoning. A decision about a similar case can show how reviewers weigh evidence. Treat it as an example, not as a rule your plan must follow.
8. Put it in the appeal. Name each source in your appeal letter and enclose it. See how to write an appeal letter that works.

If the plan says “experimental”

Ask the plan how it defines “experimental” or “investigational”, in writing, and ask for the plan provision. Then answer with:

• journal articles about the treatment for your condition;
• guidelines that include it;
• regulatory approvals; and
• your doctor’s experience.

The FAIR Health guide suggests this list. The Arthritis Foundation likewise points to peer-reviewed literature when a plan says a treatment’s effectiveness is not proven. See the page on experimental or investigational denials.

If your doctor is recommending a use that is not on the drug’s label, use the off-label letter and the experimental appeal letter.

What the plan may say, and what to say back

“The studies do not apply to your situation.” Ask which difference matters, in writing, and ask your doctor to address it in a short addendum.

“This is not in our criteria.” Ask what evidence the criteria rest on, and give the plan the guideline your doctor relies on. A reviewer has to consider material the first decision never saw.

“The treatment is investigational.” Ask the plan to name the provision and its definition. Then respond with evidence that matches that definition.

The rule

A non-grandfathered plan may not deny a qualified individual participation in an approved clinical trial, and may not deny or limit coverage of routine patient costs, meaning items and services the plan would typically cover for someone not in a trial. See section 300gg-8 of Title 42 of the United States Code: 42 U.S.C. 300gg-8.

Watch for

• Medicare Advantage. A Medicare Advantage plan must follow Original Medicare’s coverage rules. It may write its own criteria only when Medicare’s are not fully established, and they must rest on current evidence in widely used treatment guidelines or clinical literature, with the plan posting a summary of the evidence and its reasoning. Ask for that summary.
• Old or weak sources. Check dates. Use the current edition of a guideline, and ask your doctor if a newer study changes the picture.
• Do not diagnose yourself. Do not send evidence that suggests a different condition or treatment than your doctor’s. Talk to your doctor first.
• Do not overstate. Say what the source says. A reviewer who finds a claim the source does not make may distrust the rest.

What next

• How to find the insurer’s medical policy: the plan’s side of the evidence.
• What a strong letter of medical necessity contains: where your doctor cites it.
• How external review works: what happens if the plan still says no.