How to Choose the Best Medical Chronology Service

Here is how to choose the best medical chronology service: test whether every entry traces to a source page, how AI output is reviewed, and whether the records are complete. Ethics guidance treats AI work as a starting point a lawyer must verify, so traceable medical chronologies matter most [1].

Start with traceability

The single most useful test is simple: pick ten entries and find each one in the records. A good chronology lets a reviewer do that in seconds. Each entry should name the provider, the date of service and the exact page it came from.

Without page-level citations, a chronology can't be checked. Someone has to rebuild it before it goes into a demand, a deposition outline or an expert packet. That rework erases most of the time the service was meant to save.

Ask every provider for a sample built from a de-identified file. Then run the ten-entry test yourself. It tells you more than any feature list.

Ask how AI output is checked

Most chronology services now use large language models for the first pass. That can speed up the work, but the error types are well documented and worth asking about by name.

A 2025 study in npj Digital Medicine reviewed 12,999 clinician-annotated sentences from model-written clinical notes. It found a 1.47% hallucination rate and a 3.45% omission rate [2]. Of the 191 sentences with hallucinations, 84 were major errors that could affect diagnosis or care if left uncorrected [2].

A 2026 study in PLOS Digital Health found two recurring errors in emergency department summaries. The first was "timeline collapse," where chronic conditions were shown as new complaints. The second was result misattribution, where older test results were tied to the wrong visit [3]. Both errors would damage a chronology, because a case often turns on which condition came first.

Good answers to "how is AI output checked?" are specific:

• Who reviews each draft, and what are their qualifications?
• Is every entry checked against its cited page, or only a sample?
• How are pre-existing conditions separated from new injuries?
• What happens when the record conflicts with itself?

Texas ethics guidance puts the duty plainly. AI output "must always be carefully analyzed for accuracy and quality," and the lawyer remains responsible for the final work [1]. A provider's review process is part of how the firm meets that duty.

Compare the service models side by side

Chronology work is usually bought in one of three ways. Each fits a different bottleneck.

The right column depends on where your team loses time. If attorneys wait on medical analysis, a nurse-led service may fit. If paralegals spend days sorting pages, software may fit. Many firms use more than one model.

Check the records before the chronology

A chronology is only as complete as the records behind it. If a provider's records are missing, the timeline has a gap, and the gap often shows up at the worst moment.

Tavrn's own request data shows that 37% of a patient's record sits outside every network and portal combined. Those visits only come back when someone asks the provider directly. Before comparing chronology services, confirm the file includes every provider the client saw, including billing records and imaging reports where they matter.

Confirm the HIPAA and security paperwork

A chronology provider that handles protected health information for a firm is usually a business associate under HIPAA. The federal definition includes subcontractors that create, receive, maintain or transmit that information [4]. HIPAA requires satisfactory assurances, through a business associate contract, before that information changes hands [5].

Ask each provider for four documents:

• A signed business associate agreement.
• A current SOC 2 report. SOC 2 covers controls for security, availability, processing integrity, confidentiality and privacy [6].
• A description of encryption at rest. AES, defined in FIPS 197, supports 128, 192 and 256-bit keys [7].
• A description of encryption in transit. NIST guidance requires TLS 1.2 support and TLS 1.3 support for government systems [8].

If a provider can't produce these on request, keep looking.

Read turnaround claims carefully

A turnaround promise only means something if you know when the clock starts. Some providers start counting when they have every record. Others start when the first file arrives. Ask for the definition in writing.

Also ask what happens when new records arrive mid-case. A good service updates the existing chronology and marks what changed. A weak one starts over, or adds entries out of order.

Signs you picked the wrong provider

Most problems show up within the first few files. Watch for these:

• Entries with no page citation, or citations that point to the wrong page.
• Old conditions listed as new injuries.
• Duplicate visits from records sent twice.
• Gaps in treatment that turn out to be missing records, not missing care.
• Reviewers who can't explain how an entry was made.

Each of these costs staff time and can weaken a demand. Track them for the first month. The pattern usually tells you whether to stay or switch.

What to do next

Pick two or three providers and give each the same closed file. Run the ten-entry test, review their AI checks and collect their HIPAA paperwork. Then compare the results in the table above.

If missing records are the bigger problem, see how Tavrn retrieves records for law firms. Martay Law Office filed 65% more cases year over year after changing how it gets records. To see the process on one of your own files, book a demo.

Sources

1. Opinion 705: Use of generative AI by Texas lawyers — Professional Ethics Committee for the State Bar of Texas, 2025-02
2. A framework to assess clinical safety and hallucination rates of LLMs for medical text summarisation — npj Digital Medicine, 2025-05-13
3. Large language model-generated clinical summaries in emergency departments: A blinded comparison study — PLOS Digital Health, 2026-07-09
4. 45 CFR 160.103 Definitions — Electronic Code of Federal Regulations, current
5. 45 CFR 164.504 Uses and disclosures, organizational requirements — Electronic Code of Federal Regulations, current
6. SOC 2: SOC for Service Organizations — AICPA & CIMA, current
7. FIPS 197: Advanced Encryption Standard (AES) — NIST, 2023-05-09
8. SP 800-52 Rev. 2: Guidelines for the Selection, Configuration, and Use of TLS Implementations — NIST, 2019-08