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Organizing Communications Using Threads

Introduction

In a healthcare context, messages are sent all the time and can include many scenarios (patient to physician, physician to physician, and more), so ensuring they are well-organized is vital. This guide covers how to model and organize threads using Medplum.

  • Representing individual messages
  • Building and structuring threads
  • How to "tag" or group threads
  • Searching for and sorting communications and threads

Representing Individual Messages

The FHIR Communication resource is a representation of any message sent in a healthcare setting. This can include emails, SMS messages, phone calls and more.

ElementDescriptionRelevant ValuesetExample
payloadText, attachments, or resources that are being communicated to the recipient.You have an appointment scheduled for 2pm.
senderThe person or team that sent the message.Practitioner/doctor-alice-smith
recipientThe person or team that received the message.Practitioner/doctor-gregory-house
topicA description of the main focus of the message. Similar to the subject line of an email.Custom Internal CodeIn person physical with Homer Simpson on April 10th, 2023
categoryThe type of message being conveyed. Like a tag that can be applied to the message.SNOMED CodesSee below
partOfA reference to another resource which the Communication is a component.See below
inResponseToA reference to another Communication resource which the current one was created to respond to.Communication/previous-communication
mediumThe technology used for this Communication (e.g. email, fax, phone).Participation Mode Codesemail
subjectA reference to the patient or group that this Communication is about.Patient/homer-simpson
encounterA reference to a medical encounter to which this Communication is tightly associated.Encounter/example-appointment
sent/receivedThe time that the message was either sent or received.2023-04-10T10:00:00Z

Building and Structuring Threads

Beyond producing individual messages, most healthcare communication tools group messages into "threads". When building a thread in FHIR, it is important to consider what type of resource should be used to group the thread together. Depending on the circumstances it makes sense to use different resources.

Threads Involving Patients

If the messages are between a patient and a provider, you should use an Encounter resource to group the thread. An Encounter can be any interaction between a patient and provider, including various types of messages, so it is important that these are classified correctly. Using an Encounter resource to represent patient visits also makes it easier to submit claims to insurance to be reimbursed. For more details, please see the Representing Asynchronous Encounters docs.

Threads Between Providers

However, when a patient is not involved, threads should be grouped using the Communication resource. A thread will have a two-level hierarchy – one parent Communication resource that represents the thread itself, and child Communication resources that represent each individual message. The child resources should be linked to the parent using the partOf field, which represents a parent resource of which the current Communication is a component. This allows you to refer to the parent resource to create a thread where each message is linked to the parent as a common reference point.

In these threads, the parent resource needs to be distinguished from the children. Since the parent resource will not have any content or refer to a parent of its own, this can be done by omitting a message in the payload field and a resource reference in the partOf field.

Additionally, to help organize threads, it is useful to use add a topic element to give the thread a subject. Similar to the subject line of an email, the topic should be given a high level of specificity to help distinguish the thread. The topic should be assigned to both the parent and children Communication resources in any thread.

Coding the topic field

Because of how specific the topic field should be, it is best to use a custom coding rather than LOINC or SNOMED codes to classify the element.

Example of a thread grouped using a Communication resource
  {
resourceType: 'Communication',
id: 'example-parent-communication',
// There is no `partOf` of `payload` field on this communication
// ...
topic: {
text: 'Homer Simpson April 10th lab tests',
},
},

// The initial message
{
resourceType: 'Communication',
id: 'example-message-1',
payload: [
{
id: 'example-message-1-payload',
contentString: 'The specimen for you patient, Homer Simpson, has been received.',
},
],
topic: {
text: 'Homer Simpson April 10th lab tests',
},
// ...
partOf: [
{
resource: {
resourceType: 'Communication',
id: 'example-parent-communication',
},
},
],
},

// A response directly to `example-message-1` but still referencing the parent communication
{
resourceType: 'Communication',
id: 'example-message-2',
payload: [
{
id: 'example-message-2-payload',
contentString: 'Will the results be ready by the end of the week?',
},
],
topic: {
text: 'Homer Simpson April 10th lab tests',
},
// ...
partOf: [
{
resource: {
resourceType: 'Communication',
id: 'example-parent-communication',
},
},
],
inResponseTo: [
{
resource: {
resourceType: 'Communication',
id: 'example-message-1',
},
},
],
},

// A second response
{
resourceType: 'Communication',
id: 'example-message-3',
payload: [
{
id: 'example-message-2-payload',
contentString: 'Yes, we will have them to you by Thursday.',
},
],
topic: {
text: 'Homer Simpson April 10th lab tests',
},
// ...
partOf: [
{
resource: {
resourceType: 'Communication',
id: 'example-parent-communication',
},
},
],
inResponseTo: [
{
resource: {
resourceType: 'Communication',
id: 'example-message-2',
},
},
],
},

How to Tag or Group Threads

It can be useful to "tag", or group, threads so that a user can easily reference or interpret a certain type of message at a high level. For example, if there is a thread about a task that needs to be performed by a nurse, it can be tagged as such.

Tagging can be effectively done using the Communication.category element, which represents the type of message being conveyed. It allows messages to be classified into different types or groups based on specifications like purpose, nature, or intended audience.

When assigning a category to a thread, it should be included on both the parent and child Communication resources. It is also important to note that the category field is an array, so each Communication can have multiple tags.

Here are some common types of tags that can be used for grouping:

Type of TagCodesystem
Level of credentialSNOMED Care Team Member Function valueset
Clinical specialtySNOMED Care Team Member Function valueset
Product offeringSNOMED, LOINC, Custom Internal Coding
Example of Multiple Categories
  {
resourceType: 'Communication',
id: 'example-communication',
category: [
{
text: 'Doctor',
coding: [
{
code: '158965000',
system: 'http://snomed.info/sct',
},
],
},
{
text: 'Endocrinology',
coding: [
{
code: '394583002',
system: 'http://snomed.info.sct',
},
],
},
{
text: 'Diabetes self-management plan',
coding: [
{
code: '735985000',
system: 'http://snomed.info.sct',
},
],
},
],
};
Designing category schemes

There are different ways that you can categorize threads, each one with its own pros and cons. For example, you can have threads with multiple category fields, one for specialty and one for level of credentials, etc., where you would search for multiple categories at once. The pros to this are that the data model is more self-explanatory, since each category is explicitly represented, and better maintainability, since it is easier to update and add individual categories. However, this can also lead to more complex queries.

Alternatively, you can have threads that have just one category that combines specialty, level of credentials, etc., and search for that specific category. This allows for simpler searching, needing only one category search parameter, and a simpler, more compact data model. The downside is that it may require more parsing and logic on the front-end to handle the combined categories and that as more combinations arise, maintaining the coding system may become difficult.

Searching for and Sorting Communication Resources

Searching for All Threads in a System

When searching for threads, we need to differentiate between threads that are grouped by the Communication resource and those that are grouped with the Encounter resource. We'll begin with threads grouped by Communication.

To search for all threads in the system, we need to find each parent Communication resource. One of the factors that differentiates a "thread-level", or parent, resource from a "message-level", or child, resource is that thread-level resources do not have a value in the partOf field.

// Search for a Communication-grouped thread
await medplum.searchResources('Communication', {
'part-of:missing': true,
});

In this example, we use the :missing search modifier to search for any Communication resources that do not reference another resource in their partOf field. This gives us the parent Communication of all threads in the system.

Searching For All Messages in a Thread

Once you have found the thread you want, you may want to retrieve the messages from only that specific thread, in order. In the above example, though we retrieved the messages with each thread, there is no guarantee that they will be in the correct order. You can also filter down results so that you only get the messages specific to the thread you want.

Again, we will separate how to search for Communication and Encounter grouped threads, beginning with Communication.

await medplum.searchResources('Communication', {
'part-of': 'Communication/example-communication',
_sort: 'sent',
});

In the above example, we search for Communication resources that reference our parent in the partOf field and sort by the sent field. For more details on using the search functionality, see the Search docs.

To search for specific threads that are grouped by Encounter:

await medplum.searchResources('Communication', {
encounter: 'Encounter/example-encounter',
_include: 'Communication:encounter',
_sort: 'sent',
});

In this example, we search for any Communication resource that references our Encounter in the encounter field. We also _include that Encounter, though you can leave this out if you only want to return the messages themselves. We then use _sort to get them in the order they were sent.

Putting It All Together

To put this all together, we can also search for all threads and return their messages with them.

await medplum.searchResources('Communication', {
'part-of:missing': true,
_revinclude: 'Communication:part-of',
});

Here we are using the same initial search to return all of the parent threads in the system. However, we include the _revinclude parameter, allowing us to also search for all Communication resources that reference one of our search results in the partOf field. This allows us to return all of the child messages as well.

Searching for threads grouped by Encounter is a little different. Since there is no link from the parent Encounter to the child messages, we still search for Communication resources at the top level.

await medplum.searchResources('Communication', {
'encounter:missing': false,
_include: 'Communication:encounter',
});

In this example, we set the encounter:missing parameter to false, to include only Communication resources that reference an encounter. We then use _include to include those Encounter resources in our search results. Note that this search will include all of the messages as well as the parent resources.

You can also filter down your searches further by including additional parameters.

await medplum.searchResources('Communication', {
'part-of:missing': true,
_revinclude: 'Communication:part-of',
subject: 'Patient/example-patient',
});
await medplum.searchResources('Communication', {
'encounter:missing': false,
_include: 'Communication:encounter',
subject: 'Patient/example-patient',
});

Here we build upon our search by adding the subject parameter to search for all threads that are related to a given patient. For other items to filter your search on, see the Communication Search Parameters.