How to compare a similar case with your own

The label describes a reason to compare two stories; it does not mean the people have the same diagnosis, cause, severity, treatment needs, or outcome.

On SameCase, matching is text-similarity retrieval rather than a clinical assessment. Appraise a result in three passes: identify what actually matched, check whether the case is complete enough to inspect, and decide what its design and evidence can support. If a key detail is absent, label it missing or unclear instead of filling the gap from the final diagnosis.

Do not let a memorable diagnosis or outcome answer the comparison before you inspect it. First separate retrieval, reporting, and relevance. A page can be easy to read but weakly matched; closely matched but incomplete; or detailed but unable to support the conclusion a reader wants to draw.

• Match: Which exact features, order, or phrases overlap, and which important features differ?
• Inspectability: Does the case show enough context, chronology, assessment, diagnostic basis, intervention, follow-up, harms, sources, and limitations to examine the claim?
• Relevance: Is the case's narrow lesson applicable to the question at hand, and what stronger independent evidence or local clinical assessment is still needed?

Copy these prompts into a note and mark each one present, missing, unclear, or not relevant. Record only what you need for the discussion, and do not place another person's private health information in a public note or search box.

• Learn from real cases shared by patients and doctors. Compare the details and discuss useful ideas with the doctor caring for you.
• Provenance: Who wrote, published, or checked it; when was it published or updated; and are sources, conflicts, corrections, and the content status visible?
• Patient and setting context: Are the characteristics and care setting needed to understand the case described without unnecessary identifying detail?
• Timeline: Can you follow the order of symptoms, assessments, interventions, changes, and follow-up?
• Presentation: Are the important symptoms, examination findings, test results, and relevant negative findings shown rather than only the surprising details?
• Diagnostic basis: What evidence supports the stated diagnosis or resolution, and is it clear what was confirmed versus inferred?
• Alternatives: Does the report say what other explanations were considered and what evidence argued for or against them?
• Intervention: If a treatment or procedure matters to the lesson, are its timing and relevant details described?
• Outcome and harms: Is follow-up long enough to understand the reported outcome, and are adverse or unexpected events addressed?
• Claim boundary: Does the conclusion stay within what one case can illustrate, without turning sequence into causation or one outcome into a general treatment effect?
• Exact overlaps: Write the two or three features that genuinely match before looking for more similarities.
• Important differences: Record differences in timing, context, objective findings, medicines, exposures, assessment, setting, or follow-up that could change interpretation.
• Missing information: List any detail needed for comparison that neither the case nor the current clinical record supplies.
• Evidence beyond the case: Identify a current guideline, systematic review, test reference, regulator notice, or specialist assessment needed before the case changes a decision.
• Useful action: Convert the comparison into one neutral question; do not copy the case's diagnosis, test, or treatment into a personal plan.

The CARE guideline is a reporting guideline for authors: it prompts transparent description of items such as patient information, clinical findings, a timeline, diagnostic assessment, intervention, follow-up, outcomes, limitations, patient perspective, and consent. The JBI case-report checklist was developed for critical appraisal within evidence synthesis and asks whether core case details are clearly described.

Those tools help a reader see what information is present. They do not make a diagnosis true, remove selection or reporting bias, establish that an intervention caused an outcome, or show that a case applies to another person. A detailed case can still support only a narrow observation, while a missing detail should lower confidence in the comparison rather than be guessed.

An AHRQ methods guide describes a case report as a single-participant account without a control group. It can be useful for an unusual disease, atypical presentation, or newer intervention, but it cannot measure incidence or risk, and it cannot establish an association between an intervention and an outcome from the case alone. Reporting and selection biases remain possible.

A case library adds another selection layer: unusual, solved, or educational stories are more likely to be contributed and noticed than routine or unresolved encounters. Counts, match order, and the absence of a match therefore cannot be converted into prevalence, personal probability, treatment benefit, or a rule-out conclusion.

Applicability is not a single resemblance score. AHRQ's applicability guidance asks evidence reviewers to consider which patients and circumstances a body of evidence can inform. For one retrieved case, use the same caution at a smaller scale: describe the dimensions of fit and mismatch, but do not treat this checklist as a validated applicability method.

• Person and context: age range, relevant history, pregnancy status, medicines, exposures, and care setting when those details matter.
• Problem and time course: onset, order, duration, recurrence, severity, and trajectory.
• Objective information: examination, tests, images, pathology, and important negative findings.
• Diagnostic basis: criteria, confirmatory evidence, specialist judgment, longitudinal course, and unresolved uncertainty.
• Intervention and alternatives: what happened before and after an intervention, what else changed, and what competing explanation remains possible.
• Outcome and follow-up: what was measured, by whom, for how long, and whether harms or later changes were captured.
• System fit: whether local resources, pathways, definitions, and jurisdiction differ from the case setting.

Keep the note short enough to use in a real appointment or clinical discussion. The goal is to expose the comparison, not to make the case win the differential diagnosis.

• Case or source: [case ID or title, publisher, URL, and date checked]
• Why it was retrieved: [the feature, sequence, exposure, or wording that matched]
• Exact overlaps: [two or three specific similarities]
• Important differences: [details that could change interpretation]
• Missing or unclear: [information needed but not reported]
• Learn from real cases shared by patients and doctors. Compare the details and discuss useful ideas with the doctor caring for you.
• Evidence beyond the case: [guideline, review, test evidence, or specialist input to check]
• Neutral question: “This case shares [feature], but differs in [difference]. Does that pattern change what should be considered or followed up here, and why or why not?”
• Agreed next step and safety net: [who owns follow-up, expected timing, and when to seek earlier help]

Do not start, stop, borrow, or change a medicine because it appeared in a case. Do not pursue a test without a clinician who can explain whether it is appropriate and interpret the result, and do not delay care while searching for a closer story. If symptoms are severe, sudden, or worsening quickly, use local urgent or emergency services and any existing safety plan instead of completing this checklist.

If a match increases anxiety, step back from the final diagnosis and return to the facts you can report: what is happening, when it began, how it is changing, and which objective findings are available. The responsible clinician may explain that a memorable match is not applicable; identifying a misleading comparison is a useful result.

JBI's checklist is designed for formal case-report appraisal in evidence synthesis, CARE is a reporting guideline, and the AHRQ methods sources address study design and applicability in evidence reviews. The checklist on this page is a SameCase editorial synthesis for comparing retrieved narratives; it is not the JBI or CARE instrument and should not be converted into a numeric diagnosis, quality, or relevance score.

This combined checklist has not been validated to improve diagnosis, treatment selection, safety, or outcomes, and no named clinician or research-methods reviewer is assigned. SameCase's own policy is first-party evidence for how its matching is described, not independent proof that retrieval is clinically accurate. Use the page for education and question preparation, alongside the responsible clinician, current evidence, and local pathways.