Malfunctions in distributed clinical decision support: 3 cases from a multi‑component clinical decision support...

Clinical decision support (CDS) is increasingly delivered through distributed architectures that connect electronic health record (EHR) workflows to external services and community partners. While these designs enable rapid deployment and interoperability, they also introduce new failure modes that can silently disrupt time‑sensitive care processes. Practical, real‑world descriptions of these distributed CDS malfunctions remain limited.

We describe 3 malfunctions in a distributed CDS system used to support smoking cessation referrals. The issues reflected common distributed‑system failure modes, including clock drift, timing‑related data availability problems, and asynchronous processing across partner systems.

Given the implications software architecture can have on distributed systems, it is critical to expand the definition of what constitutes the CDS system to include components outside the EHR, including those of third-party partners system. Further, monitoring techniques for distributed systems may also require multiple methods to account for differences in how each component can fail.