Healthy Route Implementation Guide
0.1.0 - ci-build

Healthy Route Implementation Guide, published by Savannah Informatics. This guide is not an authorized publication; it is the continuous build for version 0.1.0 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/savannahghi/healthy-route-ig/ and changes regularly. See the Directory of published versions

Documents

Every document the study holds, and the one that carries a signature.

Two profiles, one small and one specific

HRDocumentReference constrains what is true of every document regardless of purpose. HRConsentEvidence derives from it and describes the photographed page a participant signed.

The study already holds two kinds of document and will hold more: the approved blank information sheet and consent form, the signed page, laboratory reports, and the letter sent with a participant who is referred. They differ in almost every respect, so the base profile is deliberately small.

What the base decides, and why only that

Two constraints are placed on the base rather than repeated on each derived profile.

The tenant extension is required. A document profile added later cannot omit it. This is the whole reason the base exists: an invariant enforced by inheritance does not depend on the next author remembering it.

Inline content is prohibited. content.attachment.data is 0..0 and content.attachment.url is 1..1. Base64 content travels wherever the resource travels, including into search bundles and audit payloads assembled for entirely unrelated purposes. Referencing the file keeps it out of the response to every read, and allows access to the document to be authorised and logged separately from access to the metadata describing it.

content.attachment.hash is Must Support. The question of whether a stored file is still the file that was registered is only ever asked long after the fact, and it cannot be answered unless the hash was recorded at the time.

What the base deliberately does not decide

Two constraints are absent from the base, and their absence is the reason the split falls where it does.

subject stays 0..1. The approved blank consent form is a document about no one. Requiring a subject on the base would make it unrepresentable. The type is still constrained to Patient, so a document is never hung off an arbitrary resource — but it may have no subject at all.

securityLabel stays unconstrained. The blank form is the approved public text. The signed page is the most identifying object the study holds. A classification correct for one is wrong for the other, and a base profile that picked either would be wrong half the time.

The signed page

HRConsentEvidence is optional, and not required by the protocol.

The protocol requires the investigator to retain the signed form and states that no records may be transferred to another location or party without written notification to the sponsor. What it requires of the record is a statement that consent was obtained, the date, and who took it — all of which HRConsent carries on its own.

This profile exists for sites that choose to hold the page within their own tenant. Using it is a decision for the site and its ethics committee rather than one the protocol settles.

It is never exported

The image carries a name and a signature together. Nothing about it is de-identifiable: a redacted signature is not evidence that consent was given.

There is therefore no export counterpart to this profile, and the absence is deliberate.

It is not, however, yet enforced. This guide defines no export manifest, and the only artefact describing what may leave a tenant is HRExportPatient. Until an enumerated export set exists, the prohibition rests on there being no profile to export this resource against, rather than on a rule a consumer can validate against. That manifest is outstanding work and is tracked as such.

securityLabel carries a restricted confidentiality classification, applied at creation rather than assigned by policy at read time, so that a copy of the resource carries its classification with it and does not depend on the server that serves it to apply one.

A participant re-consenting to an amended form produces a second page. The earlier page is set to superseded and retained rather than replaced: it remains the evidence for activity that took place while it was in force. relatesTo links the two, which is what allows the version in force on a given date to be established.

Witnesses

attester covers the case where a participant cannot read the form and it is read to them in the presence of an impartial witness. The protocol provides for this, and a signature alone does not evidence it.

Which profile for which document

Document Profile Subject Security label
approved blank consent form HRDocumentReference absent none required
signed consent page HRConsentEvidence required restricted
laboratory report to be added required to be decided
referral letter to be added required to be decided