How to Read Sufficient/Necessary/One or More Notation

In addition to the narrative portion of a position statement, the case ascertainment and case classification criteria are also captured within tabular format as a part of the technical supplement to a CSTE standardized surveillance position statement. This technical supplement is meant to translate the information into a machine-processable format for use in developing algorithms for computerized processes such as electronic case reporting. Three letters may be used to identify if a criterion is “sufficient”, “necessary”, or “one or more”:

S = This criterion alone is SUFFICIENT to report a case. There may be multiple “S” criteria for a disease/condition or subtype.

N = All “N” criteria in the same column are NECESSARY to report a case. An “N” criterion should be accompanied by at least one additional “N” criterion or at least one “O” criterion within a single column.

O = At least one of these “O” (ONE OR MORE) criteria in each category (categories=clinical, laboratory, epidemiologic linkage, vital records, healthcare records, etc.) in the same column – in conjunction with all “N” criteria in the same column – is required to report a
case. These “O” criteria are alternatives, meaning that a single column can have no “O” criteria, OR only “O” criteria without any “N” criteria, OR at least one “O” criterion in conjunction with “N” criteria.

Within 23-MCH-01, tables VI, VII.A and VII.B describe the case ascertainment and case classification criteria utilizing this format. These tables
contain logic sets (columns) that indicate different combinations of criteria that a case would need to meet to be reported.