Understanding the API Results

For search queries (such as: https://api.fda.gov/other/substance.json?search=definition_type:"PRIMARY"), the results section includes matching adverse event reports returned by the API.

Each substance result consists of these major sections:

  • Substance:The top level fields of each record.
  • Codes:A list of codes used for this record, containing external identifiers, external classification designations, and external link-outs.
  • Mixture:A container for the mixture information necessary to define a mixture substance. This includes the mixture components and an optioanl source material reference.
  • Modifications:A container for the set of physical, structural and agent modifications on the substance record.
  • Moieties:A list of the important component chemical structures which comprise a chemical substance, as well as their relative ratios to each other (especially important in the case of non-stoichiometric chemical substances). These "moieties" are typically the unique set of disconnected covalent structures found in the substance.
  • Names:The list of names associated with a record. These include scientific, common, generic and brand names for substances and concepts. Name objects include both the name as a string, as well as other information.
  • Notes:A list of notes and general comments for the record.
  • Nucleic Acid:The definitional information of a nucleic acid substance. Contains information about the nucleic acid sequence as well as the sugars and linkages used.
  • Polymer:The definitional information of a polymer substance. Contains information about the monomers, structural repeat units, amounts, connectivity and idealized structural form of the polymer.
  • Protein:The definitional information of a protein substance. Contains information about the amino acid sequence, gylcosylation, classification, disulfide links and other links.
  • References:A list of reference uuids, which refer back to the root record's references, essentially acting as footnotes.
  • Relationships:A list of related records which share some known relationship with this record (e.g. salt forms, metabolites, impurities, etc).
  • Structurally Diverse:The definitional information of a structurally diverse substance. This includes information about the source of the material (e.g. taxonomy for organisms) as well as the state, form and part of the source material used.
  • Structure:Chemical structure of a chemical substance.

For count queries (such as: https://api.fda.gov/other/substance.json?count=substance_class), the results section will look something like the following:

[
  {
    "term": "chemical",
    "count": 72108
  },
  {
    "term": "structurallyDiverse",
    "count": 25508
  },
  {
    "term": "protein",
    "count": 4175
  },
  {
    "term": "mixture",
    "count": 2508
  },
  {
    "term": "polymer",
    "count": 2128
  },
  {
    "term": "concept",
    "count": 713
  },
  {
    "term": "nucleicAcid",
    "count": 190
  },
  {
    "term": "specifiedSubstanceG1",
    "count": 23
  }
]