Table 5.

Ontological approach to mapping COVID-19 codes.

Category	Code (and its certainty of mapping)	Notes
Confirmed case	Confirmed 2019-nCoVa (Wuhan) infection (Direct mapping codes)	Careful training will be required to ensure validity and reliability. TBCb whether we will require reference lab report
Probable case	N/Ac	It is possible we will use this category if we do not see data quality problems with definite cases. The WHOd definition is a positive pan-coronavirus assay but without sequencing and absence of other respiratory infections.
Possible case	Exposure to 2019-nCoV (Wuhan) infection Suspected 2019-nCoV (Wuhan) infection Tested for 2019-nCoV (Wuhan) infection (Partially mapping codes)	While awaiting confirmation, we will need to set a time limit (proposed 6 weeks), after which possible cases are reclassified to not a case
Not a case	Excluded 2019-nCoV (Wuhan) infection (Relevant codes with no clear mapping to 2019-nCoV)	As tested patients have negative cases and contacts do not develop symptoms. they will be placed in this category.

^a2019-nCoV: novel coronavirus.

^bTBC: to be confirmed.

^cNot applicable.

^dWHO: World Health Organization..