Chi-square-based scoring function for categorization of MEDLINE citations

TL;DR

This paper introduces a simple chi-square-based scoring method for classifying MEDLINE citations related to genetics, demonstrating comparable accuracy to machine learning techniques in biomedical text categorization.

Contribution

The study presents a novel, straightforward chi-square scoring approach for biomedical document categorization, validated against machine learning methods with promising results.

Findings

Achieved 87% predictive accuracy on MEDLINE citations

Performed comparably to machine learning algorithms like SVM, decision trees, and Naive Bayes

Implemented in a literature-based discovery system for gene disambiguation

Abstract

Objectives: Text categorization has been used in biomedical informatics for identifying documents containing relevant topics of interest. We developed a simple method that uses a chi-square-based scoring function to determine the likelihood of MEDLINE citations containing genetic relevant topic. Methods: Our procedure requires construction of a genetic and a nongenetic domain document corpus. We used MeSH descriptors assigned to MEDLINE citations for this categorization task. We compared frequencies of MeSH descriptors between two corpora applying chi-square test. A MeSH descriptor was considered to be a positive indicator if its relative observed frequency in the genetic domain corpus was greater than its relative observed frequency in the nongenetic domain corpus. The output of the proposed method is a list of scores for all the citations, with the highest score given to those citations containing MeSH descriptors typical for the genetic domain. Results: Validation was done on a set of 734 manually annotated MEDLINE citations. It achieved predictive accuracy of 0.87 with 0.69 recall and 0.64 precision. We evaluated the method by comparing it to three machine learning algorithms (support vector machines, decision trees, na\"ive Bayes). Although the differences were not statistically significantly different, results showed that our chi-square scoring performs as good as compared machine learning algorithms. Conclusions: We suggest that the chi-square scoring is an effective solution to help categorize MEDLINE citations. The algorithm is implemented in the BITOLA literature-based discovery support system as a preprocessor for gene symbol disambiguation process.