Table 1.

Summary of the advantages and disadvantages of the clinical data abstraction methods

	Manual	Simply query	NLP
Advantages	• Review of entire record enables collection of clinical details • Discrete data elements retrieved from large volumes of data • Discover clinical decision support alerts	• Needed for searching full free text entries • Providers prefer to enter free text • Free text is required for complex requirements such as clinical trial recruitment	• Can convert unstructured free text into structured and codified format • Less time • Less effort • Can recognize related words and phrases • Sift through large volumes of data quickly • Useful for MU, quality measures
Disadvantages •Unstructured notes more difficult to abstract • Unreliable results • Time consuming • Expensive	•Difficult to retrieve:  1. Abbreviations  2. Negations  3. Acronyms  4. Hedge phrases  5. Lack of standard grammar and punctuation	• Cost • Still need to do quality control and other validation techniques