💭 Thoughts on FHIR CDS Hooks and Practice Advisories

CDS Hooks and Practice Advisories

Thoughts on FHIR CDS Hooks and Practice Advisories

Clinical decision support (CDS) has evolved dramatically over the past decade, yet the adoption of FHIR CDS Hooks and Practice Advisories remains limited. While these technologies promise real-time, event-driven decision support that reduces provider burden, EHR vendor support has lagged.

With HTI-2 (Health Data, Technology, and Interoperability) pushing for broader adoption, and Epic’s August 2024 Launch Cards enabling tighter integration with SMART on FHIR apps, we may finally see meaningful traction.

📜 Origins: The PAMA Act of 2014

The foundation for CDS Hooks was laid by the Protecting Access to Medicare Act (PAMA) of 2014, which introduced Appropriate Use Criteria (AUC) for clinical decision support. The goal? Reduce unnecessary imaging and testing by embedding decision support into provider workflows.

Fast forward to today, and FHIR CDS Hooks has emerged as a modern approach to fulfilling this vision. It enables event-driven decision support, automatically surfacing relevant information at the moment of care.

🏥 CDS Hooks & Practice Advisories: How They Work

🔗 What Are CDS Hooks?

CDS Hooks is an FHIR-based, event-driven system that allows external decision support services to integrate with an EHR in real-time. When an event (like prescribing a medication) occurs, the EHR makes a hook call to an external service, which responds with cards containing decision support.

  • Event-driven: Hooks trigger based on clinician actions.
  • Standardized: Built on FHIR R4.
  • Interoperable: Supports external decision support services.

📢 What Are Practice Advisories?

Practice Advisories are configurable alerts that clinicians can enable within their EHR. They provide non-intrusive reminders based on clinical protocols. Public facing example below:

Practice Advisories

  • Less intrusive than hard stops.
  • Configurable by individual clinicians.
  • Common use cases: Sepsis detection, risk alerts, best practice recommendations.

Why does this matter? Unlike rigid CDS rules, Practice Advisories allow customization, which reduces provider abrasion while still improving care.

🚧 Hurdles to Adoption

1️⃣ Lack of Mainstream Support

While Josh Mandel (CDS Hooks creator) has driven adoption, traction remains limited. Many EHR vendors have been slow to implement hooks beyond medication ordering. The official CDS Hooks site is the best reference, and Josh deserves credit for keeping this alive.

2️⃣ Limited EHR Testing Support

Developers face a Catch-22: EHRs like Epic offer limited sandbox testing. We found paying Epic $380/hour for live vendor services testing was essential to building a functional CDS Hooks application before rolling it out to providers.

3️⃣ Variability Across Epic Instances

The phrase “Once you’ve seen one Epic instance, you’ve seen one Epic instance” holds especially true for CDS Hooks and Practice Advisories.

  • Practice Advisory Cards can fire from within Epic and from an external CDS Hook, leading to potential collisions.
  • Different Epic configurations affect behavior, requiring custom tuning per health system.

All of this leads to a lot of trial and error when building CDS Hooks applications. Discovering the art of the possible is a long process the first time around, and the learning curve is steep.

🚀 Epic’s August 2024 Launch Cards: The Game Changer?

In August 2024, Epic introduced Launch Cards, bridging the gap between CDS Hooks and SMART on FHIR.

  • Launch Cards allow SMART on FHIR apps to launch directly from a CDS Hook response.
  • This enables deeper integrations, where a CDS Hook doesn’t just show a card—it opens a full app inside the EHR.

🔄 How It Works

  1. CDS Hook fires (e.g., a provider selects a medication).
  2. CDS Service returns a Launch Card.
  3. The EHR launches a SMART on FHIR app, pre-populated with context.

This makes CDS Hooks a direct gateway to SMART apps, finally aligning decision support with FHIR R4 workflows.

🏗️ The Future: More Vendor Support & Tooling Needed

With HTI-2 pushing mandates, vendors will have to improve support. However, to truly drive adoption, we need:

✅ More open testing environments (sandbox + vendor service support).
✅ Standardized workflows for managing Practice Advisories & CDS Hooks together.
✅ Greater EHR buy-in to Launch Cards, enabling seamless CDS-to-SMART transitions.

FHIR CDS Hooks has massive potential—but we need more real-world implementation and better tooling. Until then, adoption will remain niche, despite the clear clinical benefits.

👉 What’s your experience with CDS Hooks? Have you tried integrating Practice Advisories in Epic? Let’s discuss.
📌 Read our public HTI-2 comment.