A computer-implemented apparatus or method, or a software product, for generating a composite quantitative comparison of drug products based on multiple attributes of them. A set of name-attribute similarity scores are generated based on similarities among the names of selected target and reference drugs. A set of product-attribute similarity scores are generated based on similarities among product attributes of the selected target and reference drugs. A target drug confusability score is generated based on the confusability of the target drug as compared to a population of other drugs. The composite quantitative comparison is generated based on a composite of the name-attribute and product-attribute similarity scores, and the target confusability score. A set of one or more severity of confusion scores may also be included in the composite quantitative comparison. These scores are based on one or more indicators of the severity of the consequences to a patient of confusing the target and reference drugs so that, for example, the wrong drug is administered to the patient, or the correct drug is incorrectly administered. The name-attribute similarity scores may be generated based on orthographic, phonetic, and/or phonological analysis. The product-attribute similarity scores may be generated based on the drugs'strengths, indications, dosages, administration routes, manufacturers, pharmacological categories, storage requirements, colors, shapes, legal standing, trademark description, and/or other attributes. The composite quantitative comparison may include severity-weighted similarity scores or both similarity scores and severity of confusion scores. The severity of confusion indicators may include a therapeutic index and/or a contraindication index.