Mind the Gap: Identifying What Is Missed When Searching Only the Broad Scope with Clinical Queries
MetadataShow full item record
Objectives: PubMed Clinical Queries are subdivided into “broad” and “narrow” versions, tuned to maximize retrieval sensitivity and specificity respectively by using similar but different sets of terms. This study seeks to determine whether narrow results are always a subset of broad results, and if not, quantify what is missed using only the broad search scope. Methods: For each of the five sets of PubMed Clinical Query filters, “broad” and “narrow” versions were searched against the PubMed database. Citations found using the narrow scope but not the broad were counted, and a degree of difference between the two sets was computed. As an assessment of whether these results might pertain in more typical use, this process was repeated using a set of clinically-relevant terms, ranging from fairly wide in scope, such as “heart disease”, to relatively narrow, such as “Vitamin D Deficiency Anemia”. Results: Aside from “Therapy”, searches using each filter missed potentially relevant citations when searching Filter/Broad alone. The greatest difference between the sets Filter/Broad and Filter/Narrow NOT Filter/Broad were seen when searching “Prognosis”. The ratio of items uniquely retrieved by Prognosis/Narrow to those found by using Prognosis/Broad ranged from 0.073 in all PubMed to 0.102 when searching using clinical terms. The degree of difference was less dramatic for “Diagnosis” (all PubMed: 0.037, clinical term set: 0.008), “Clinical Prediction Guides” (all: 0.026, clinical: 0.014) and “Etiology” (all: 0.008, clinical: 0.008). Conclusions: For “Prognosis”, “Diagnosis”, “Etiology” and “Clinical Prediction Guides”, these differences in retrieval between Filter/Broad and Filter/Narrow NOT Filter/Broad mean that there are many potentially relevant citations that are missed when searching the broad scope alone. Users interested in retrieving as many relevant citations as possible should likely consider ORing the broad and narrow scopes together.