Has anyone modelled a primary care appointment book using FHIR resources?
I'm wanting to model a book which allows slots to be held by more than one Practitioner (e.g. doctor and nurse), and a Location to be held against each Slot.
Currently I can't see a way of representing this, as a Schedule (and Slot by inference) can only be linked to one actor (Practitioner/Location etc).
Or if we create a seperate Schedule for each actor, how do you bundle the Practitioner and Location Slots together to create a single bookable entity?
You do this using a healthcare resource as the placeholder that the practitioners are associated with.
And yes I would expect that each of the resources would have their own schedule and slots. This way you can detect conflicts for the individual resources when allocating practitioners to the apointment.
Depends on your business rules.
Will be doing this shortly too, and will share the learning's. Will be for a community clinic, then for gp services.
Brian
Related
Quick question on Foreign key in Microservices. I already tried looking for answer. But, they did not give me the exact answer I was looking for.
Usecase : Every blog post will have many comments. Traditional monolith will have comments table with foreign key to blog post. However in microservice, we will have two services.
Service 1 : Post Microservie with these table fields (PostID, Name, Content)
Service 2 : Comments Microservie with these table fields (CommentID, PostID, Cpmment)
The question is, Do we need "PostID" in service 2 (Comments Microservice) ? I guess the answer is yes, as we need to know which comment belongs to which post. But then, it will create tight coupling? I mean if I delete service 1(Blog post service), it will impact service 2(Comments service) ?
I'm going to use another example I'm more familiar with to explain how I believe most people would do this.
Consider an Order Management System (OMS) and an Inventory Management System (IMS).
When a customer places an order in the company web site, we ask the OMS to create an order entry in the backend (e.g. via an HTTP endpoint).
The OMS system then broadcasts an event e.g. OrderPlaced containing all the details of the customer order. We may have a pub/sub (e.g. Redis), or a queue (e.g. RabbitMQ), or an event stream (e.g. Kafka) where we place the event (although this can be done in many other ways).
The thing is that we have one or more subscribers interested in this event. One of those could be the IMS, which has the responsibility of assigning the best inventory available every time an order is placed.
We can expect that the IMS will keep a copy of the relevant order information it received when it processed the OrderPlaced event such that it does not ask every little detail of the order to the OMS all the time. So, if the IMS needed a join with the order, instead of calling an endpoint in the Order API, it would probably just do a join with its local copy of the orders table.
Say now that our customer called to cancel her order. A customer service representative then cancelled it in the OMS Web User Interface. At that point an event OrderCanceled is broadcast. Guess who is listening for that event? Correct, the IMS receives notification and acts accordingly reversing the inventory assignation and probably even deleting the order record because it is no longer necessary on this domain.
So, as you can see, the best way to do this is by using events and making copies of the relevant details on the other domain.
Since events need time to get broadcast and processed by interested parties, we say that the order data in the IMS is eventually consistent.
Followup Questions
Q: So, if I understood right in microservises we prefer to duplicate data and get better performance? That is the concept? I mean I know the concept is scaling and flexibility but when we must share data we will just duplicate it?
Not really. That´s definitively not what I meant although it may have sounded like that due to my poor choice of words in the original explanation. It appears to me that at the heart of your question lies a lack of sufficient understanding of the concept of a bounded context.
In my explanation I meant to indicate that the OMS has a domain concept known as the order, but so does the IMS. Therefore, they both have an entity within their domain that represents it. There is a good chance that the order entity in the OMS is much richer than the corresponding representation of the same concept in the IMS.
For example, if the system I was describing was not for retail, but for wholesale, then the same concept of a "sales order" in our system corresponds to the concept of a "purchase order" in that of our customers. So you see, the same data, mapped under a different name, simply because under a different bounded context the data may have a different perspective and meaning.
So, this is the realization that a given concept from our model may be represented in multiple bounded contexts, perhaps from a different perspective and names from our ubiquitous language.
Just to give another example, the OMS needs to know about the customer, but the representation of the idea of a customer in the OMS is probably different than the same representation of such a concept or entity in the CRM. In the OMS the customer's name, email, shipping and billing addresses are probably enough representation of this idea, but for the CRM the customer encompasses much more.
Another example: the IMS needs to know the shipping address of the customer to choose the best inventory (e.g. the one in a facility closest to its final destination), but probably does not care much about the billing address. On the other hand, the billing address is fundamental for the Payment Management System (PMS). So, both the IMS and PMS may have a concept of an "order", it is just that it is not exactly the same, neither it has the same meaning or perspective, even if we store the same data.
One final example: the accounting system cares about the inventory for accounting purposes, to be able to tell how much we own, but perhaps accounting does not care about the specific location of the inventory within the warehouse, that's a detail only the IMS cares about.
In conclusion, I would not say this is about "copying data", this is about appropriately representing a fundamental concept within your bounded context and the realization that some concepts from the model may overlap between systems and have different representations, sometimes even under different names and levels of details. That's why I suggested that you investigate the idea of context mapping some more.
In other words, from my perspective, it would be a mistake to assume that the concept of an "order" only exists in the OMS. I could probably say that the OMS is the master of record of orders and that if something happens to an order we should let other interested systems know about those events since they care about some of that data because those other systems could have mapping concepts related to orders and when reacting to the changes in the master of record, they probably want to change their data as well.
From this point of view, copying some data is a side effect of having a proper design for the bounded context and not a goal in itself.
I hope that answers your question.
We have a monolithic Web API layer in our application with a hundred end points. I am trying to break it into microservices using Azure Service Fabric.
When we break them into multiple services, we may end up having duplicate code.
Example: Let's say we have an Account Services to create an account. And there is a payment service to apply payments to transactions.
In this case, both services need the Customer class/domain. Probably the Account Services need an exhaustive customer with full details, but the payment might need a light weight one.
The question is do we need to copy several domain entities, and other layers like this? Doesn't that create more maintenance issues?
If we don't we end up copying the code and creating different services, one monolithic service same is the existing Web API.
Any thoughts on this?
2ndly, we have some cases where transactions are mentioned today. If we separate them, is there any good design to record failures and rollback without trying too much to maintain transactions?
Breaking a monolith up into proper microservices with appropriate boundaries for your domain is certainly more of an art than a science. The prerequisite to taking on such a task is a thorough understanding of your domain and the interactions within, and you won't get it right the first time. One of points that Evans makes in his book on Domain-Driven Design is that for any sufficiently complex domain, the domain model continually evolves because your understanding of the domain is continually evolving; you will understand it a little better tomorrow than you do today. That said, don't be afraid to start when you have an understanding that is "good enough" and be willing to adapt/evolve your model.
I don't know your domain, but it sounds to me like you need to first figure out in which bounded context Customer primarily belongs. Yes, you want to minimize duplication of domain logic, and though it may not fit completely and neatly into a single service, to the extent that you make one service take primary responsibility for accessing, persisting, manipulating, validating, and ensuring the integrity of a Customer, the better off you'll be.
From your question, I see two possibilities:
The Account Services bounded context is the primary stakeholder in Customer, and Customer has non-trivial ties to other Account Services entities and services. It's difficult to draw clear boundaries around a Customer in isolation. In this case, Customer belongs in the Account Services bounded context.
Customer is an independent enough concept to merit its own microservice. A Customer can stand alone. In this case, Customer belongs in its own bounded context.
In either case, great care should be taken to ensure that the Customer-specific domain logic stays centralized in the Customer microservice behind strong boundaries. Other services might use Customer, or perhaps a light-weight (even read-only) CustomerView, but their interactions should go through the Customer service to the extent that they can.
In your question, you indicate that the Payments bounded context will need access to Customer, but it might just need a light-weight version. It should communicate with the Customer service to get that light-weight object. If, during Payments processing you need to update the Customer's billing address for example, Payments should call into the Customer microservice telling it to update its billing address. Payments need not know anything about how to update a Customer's billing address other than the single API call; any domain logic, validation, firing of domain events, etc... that need to happen as part of that operation are contained within the Customer microservice.
Regarding your second question: it's true that atomic transactions become more complex/difficult in a distributed architecture. Do some reading on the Saga pattern: https://blog.couchbase.com/saga-pattern-implement-business-transactions-using-microservices-part/. Also, Jimmy Bogard is currently in the midst of a blog series called
Life Beyond Distributed Transactions: An Apostate's Implementation that may offer some good insights.
Hope this helps!
I would like to have multiple patients related to a person (e.g. some children and their father/mother).
As the RelatedPerson has only a 1..1 cardinality, what's the best way to achieve that?
Making a resource for a parent and linking that to a RelatedPerson per patient/child resource seems inappropriate.
You can use the Person resource to link multiple RelatedPersons together to indicate that they're the same human being. RelatedPerson is intended to represent an actor who can act on behalf of the patient. As such, it's essential that there be a link to exactly one Patient so you know on who's behalf they're acting.
I am trying to understand how to use the FHIR Questionnaire resource, and have a specific question regarding this.
My project is specifically regarding how a citizen in our country could be responding to Questionnaires via a web app, which are then submitted to the FHIR server as QuestionnaireAnswers, to be read/analyzed by a health professional.
A FHIR-based system could have lots of Questionnaires (Qs), groups of Qs or even specific Qs would be targeted towards certain users or groups of users. The display of the questionnare to the citizen could also be based on a Care-plan of a sort, for example certain Questionnaires needing filling-in in the weeks after surgery. The Questionnaires could also be regular ones that need to be filled in every day or week permanently, to support data collection on the state of a chronic disease.
What I'm wondering is if FHIR has a resource which fits into organizing the 'logistics' of displaying the right form to the right person. I can see CarePlan, which seems to partly fit. Or is this something that would typically be handled out-of-FHIR-scope by specific server implementations?
So, to summarize:
Which resource or mechanism would a health professional use to set up that a patient should answer certain Questionnaires, either regularly or as part of for example a follow-up after a surgery. So this would include setting up the schedule for the form(s) to be filled in, and possibly configure what would happen if the form wasn't filled in as required.
Which resource (possibly the same) or mechanism would be used for the patient's web app to retrieve the relevant Questionnaire(s) at a given point in time?
At the moment, the best resource for saying "please capture data of type X on schedule Y" would be DiagnosticOrder, though the description probably doesn't make that clear. (If you'd be willing to click the "Propose a change" link and submit a change request for us to clarify, that'd be great.) If you wanted to order multiple questionnaires, then CarePlan would be a way to group that.
The process of taking a complex schedule (or set of schedules) and turning that into a simple list of "do this now" requests that might be more suitable for a mobile application to deal with is scheduled for DSTU 2.1. Until then, you have a few options for the mobile app:
- have it look at the CarePlan and complex DiagnosticOrder schedule and figure things out itself
- have a server generate a List of mini 1-time DiagnosticOrders and/or Orders identifying the specific "answer" times
- roll your own mechanism using the Other/Basic resource
Depending on your timelines, you might want to stay tuned to discussions by the Patient Care and Orders and Observations work groups as they start dealing with the issues around workflow management starting next month in Atlanta.
In the resource definition of a practitioner (http://hl7.org/implement/standards/fhir/practitioner.htm), only one address can be set.
These is a problem for managing physicians with a national identifier (RPPS in France). A physician can have several addresses, they can work in a public hospital and a private organization in the same time, for instance. Some physicians have more than 10 active addresses.
How to deal with that ?
Thanks in advance.
If you only want to have a single resource, you can also use extensions to send additional address repetitions (or any other element you need or don't have enough repetitions for in the core resource). The premise for only allowing 1 reptition in the "core" resource is that the majority of systems will only support one, so we didn't want to try forcing multiple repetitions. But with extensions, you're in no way limited to the cardinality indicated.
In the near future (though probably after the publication of the first DSTU), we'll probably go through all the resources and identify elements with maxOccurs=1 where it would theoretically be possible to have more than one and define standard extensions for sending extra repetitions (just so everyone who encounters this common use-case has a standard extension to rely on)
It is perfectly alright to have more than one Practitioner instance for every role an individual physician can perform. So, you get one Practitioner instance for the professional working in his role within a public hospital, one for that same person working in a private organization etcetera.
For each instance you can give the practitioner qualifications for that specific role, specify a period the professional is allowed to be in that role, give telecom details specific to that role etcetera.
See also the last paragraph in the Practitioner resource
Practitioner performs different roles within the same or even different organizations. Depending on jurisdiction and custom, it may be necessary to maintain a specific Practitioner Resource for each such role or have a single Practitioner with multiple roles. The role can be limited to a specific period, after which authorization for this role ends. Note that the represented organization need not necessarily be the (direct) employer of a Practitioner.
It looks like the value for address is an array with address object/s inside of it meaning you should be able to add as many address objects as you want in the value.
"address" : [{ Address }], // Address(es) of the practitioner that are not role specific (typically hom