Overview of The PAD term spotter
The PAD term spotter pipeline processes radiology note textual extractions specifically pertaining to the diagnosis, treatment, etc. of lower
limb Peripheral Artery Disease (PAD)(e.g. stenosis/occlusion paired with popliteal/femoral). The main feature is classifying each document for the presence of PAD.
Descriptive text of diagnosis and illness terms are paired with the site designated terms to build a relational tie, indicating a 'hit'. The pipeline
assesses presence of phrases indicative of peripheral arterial disease (PAD) in one or more sentences contained in radiology related documents.
There are four possible classification provided for PAD (positive numeric value (e.g. "3") => 'yes', "0" => 'no', "prob" => 'probable' and "-1" => 'unknown) and two
levels of classification, namely document and patient level. The precedence for classifying the patient level is PAD-Yes > PAD-prob > PAD-no > unknown (combined category).
The algorithm for classifying at the document level is as follows:
If there is no related exam type
OR no positive or negative evidence, classify as UNKNOWN;
If there is positive evidence, classify as POS;
If there is explicit evidence of negation of positive evidence
OR if a lower solo extremity exam with the discovery of no stenosis, probable or negated related PAD term exists, classify as NEG;
If there is no positive or negative evidence
OR if there is negation of positive evidence in an Ultrasound or Vascular Interventional Radiology report, classify as UNKNOWN;
Otherwise, classify as PROB based on severity modifier;