icd9IsValid: check whether ICD-9 codes are syntactically valid
In icd9: Tools for Working with ICD-9 Codes, and Finding Comorbidities

Description Usage Arguments Details Value Three-digit validation See Also Examples

This does not check whether the code coresponds to a real ICD-9-CM billing code, or parent grouping. For that, see icd9IsReal.

Factors are accepted, and since the validation is done with grepl these are handled correctly.

Currently, there is a limitation on NA values. Calling with NA (which is a logical vector of length one by default) fails, because it is not a string. This is rarely of significance in real life, since the NA will be part of a character vector of codes, and will therefore be cast already to NA_character

NA values result in a return value of FALSE.

icd9IsValid(icd9, isShort)

icd9Valid(icd9, isShort)

icd9IsValidDecimal(icd9Decimal)

icd9ValidDecimal(icd9)

icd9IsValidShort(icd9Short)

icd9ValidShort(icd9)

icd9IsValidShortV(icd9Short)

icd9IsValidShortE(icd9Short)

icd9IsValidShortN(icd9Short)

icd9IsValidMajor(major)

`icd9`	is a character vector or factor of ICD-9 codes. If fewer than five characters is given in a code, then the digits are greedily assigned to hundreds, then tens, then units, before the decimal parts. E.g. "10" becomes "010", not "0010".
`isShort`	single logical value which determines whether the ICD-9 code provided is in short (TRUE) or decimal (FALSE) form. Where reasonable, this is guessed from the input data.
`icd9Decimal`	character vector of ICD-9 codes. If fewer than five characters is given in a code, then the digits are greedily assigned to hundreds, then tens, then units, before the decimal parts. E.g. "10" becomes "010", not "0010"
`icd9Short`	is a character vector of ICD-9 codes. If fewer than five characters is given in a code, then the digits are greedily assigned to hundreds, then tens, then units, before the decimal parts. E.g. "10" becomes "010", not "0010"
`major`	character vector of 'major' part of ICD-9 codes, i.e. that part which falls before the decimal point, in decimal notation. (In 5 digit notation, the 'major' part is be the first three characters (with leading zeroes), and includes V or E prefix. xyz

Leading zeroes in the decimal form are not ambiguous. Although integer ICD-9 codes could be intended by the user, there is a difference between 100, 100.0, 100.00. Therefore a warning is given if a numeric value is provided

logical vector with TRUE or FALSE for each icd9 code provided according to its validity

isValidMajor validates just the 'major' three-digit part of an ICD-9 code. This can in fact be provided as a numeric, since there is no ambiguity. Numeric-only codes should be one to three digitis, V codes are followed by one or two digits, and E codes always by three digits between 800 and 999.

icd9IsValidDecimal, icd9IsValidShort, http://www.stata.com/users/wgould/icd9/icd9.hlp urlhttp://www.sascommunity.org/wiki/Validate_the_format_of_ICD-9_codes

Other ICD9 validation: icd9IsValidMapping

  icd9IsValidShort(c("", "1", "22", "333", "4444", "123.45", "V",
                     "V2", "V34", "V567", "E", "E1", "E70", "E"))
  icd9IsValidMajor(c("", "1", "22", "333", "4444", "123.45", "V",
                     "V2", "V34", "V567", "E", "E1", "E70", "E"))