  Background: Clinical guidelines and recommendations are the driving wheels of
the evidence-based medicine (EBM) paradigm, but these are available primarily
as unstructured text and are generally highly heterogeneous in nature. This
significantly reduces the dissemination and automatic application of these
recommendations at the point of care. A comprehensive structured representation
of these recommendations is highly beneficial in this regard. Objective: The
objective of this paper to present Clinical Recommendation Type System (CRTS),
a common type system that can effectively represent a clinical recommendation
in a structured form. Methods: CRTS is built by analyzing 125 recommendations
and 195 research articles corresponding to 6 different diseases available from
UpToDate, a publicly available clinical knowledge system, and from the National
Guideline Clearinghouse, a public resource for evidence-based clinical practice
guidelines. Results: We show that CRTS not only covers the recommendations but
also is flexible to be extended to represent information from primary
literature. We also describe how our developed type system can be applied for
clinical decision support, medical knowledge summarization, and citation
retrieval. Conclusion: We showed that our proposed type system is precise and
comprehensive in representing a large sample of recommendations available for
various disorders. CRTS can now be used to build interoperable information
extraction systems that automatically extract clinical recommendations and
related data elements from clinical evidence resources, guidelines, systematic
reviews and primary publications.
  Keywords: guidelines and recommendations, type system, clinical decision
support, evidence-based medicine, information storage and retrieval
