codematch: Select ICD10, OPCS or Read codes matching a particular...
In CALIBERcodelists: Generate ICD10, Read and OPCS codelists

Description Usage Arguments Details Value Author(s) References See Also Examples

Selects ICD10, OPCS or Read codes matching a particular pattern together with mapped terms in other dictionaries. Returns a selection object. This can be combined with the output from functions such as termhas to generate a complex query for selecting terms of interest.

1 2	codematch(regexpr, dictionary = ifelse(length(getdictionary()) == 1, getdictionary(), ""), mapStatus = NULL, exact = FALSE)

`regexpr`	Read, ICD-9, ICD-10 or OPCS code(s) to match. This can be a regular expression if EXACT = FALSE, otherwise it should be the exact code. If `regexpr` is a vector, the results are combined using OR. This is an easy way to match a list of codes.
`dictionary`	One of 'icd10', 'icd9', 'opcs' or 'read'. If not given, and if only one dictionary is in use, this dictionary is taken as the set of codes to match.
`mapStatus`	This applies to maps to/from Read only. Character vector stating which terms are acceptable to include according to the match characteristics. `D` is the default map, `A` is the alternative map, `E` is an exact match, and `G` is a map where the OPCS or ICD-10 term is more general than the Read term. `T` is not supplied by the NHS but is a mapping between identical terms (non-case-sensitive). `R` is for a term which must be ruled out before allocating a specified ICD-10 term, for example myocardial infarction must be ruled out in order to code to the ICD-10 term for essential hypertension, but myocardial infarction is not a map for essential hypertension. The default `mapStatus` is A, D, E or T when searching Read codes, and A, D, G, E or T when searching ICD-10 or OPCS codes.
`exact`	Whether the `regexpr` should be treated as a code for exact matching or a regular expression.

The maps to/from Read are provided in the NHS Read Clinical Terms Version 3, and are in the CALIBER_DICTMAPS table. The mapping between ICD-9 and ICD-10 is provided by the U.S. national Center for health Statistics and is in the CALIBER_GEM table.

A selection object.

Anoop Shah

UK Terminology Centre, National Center for Health Statistics (NCHS/CDC)

medcodeis, assigncat, dictis, explode, decode, getdictionary, setdictionary, termhas

To convert codelists from one dictionary to another: convert

# Selecting Read terms linked to ICD-10 terms for myocardial infarction
setdictionary('read')
print(codematch('I2[123]', 'icd10'))

# Look for `exact' matches and identical terms only.
print(codematch('I2[123]', 'icd10', mapStatus=c('E', 'T')))

# Selecting ICD-9 terms and linked ICD-10 terms
setdictionary('icd9', 'icd10')
print(codematch('^41', 'icd9'))
print(codematch('I20', 'icd10'))