Dear R users, An updated icd9 package is now on CRAN. Calculate comorbidities, and perform fast and accurate validation, conversion, manipulation, filtering and comparison of ICD-9-CM (clinical modification) codes. The package enables a work flow from raw lists of ICD-9 codes from hospital billing databases to comorbidities. ICD-9 to comorbidity mappings from Quan (Deyo and Elixhauser versions), Elixhauser and AHRQ included. A vignette describes the main features: http://cran.r-project.org/web/packages/icd9/vignettes/introduction.html # Version 1.0 * Calculate Charlson scores * Sum distinct comorbidities or diagnoses by patient * Core rewrite in C++ for 50+ times speed improvement. 100,000 patients assigned comorbidities in ~2 seconds. * Simplified handling validation of codes. No longer done in every function. * Most functions now guess the ICD-9 code type automatically (e.g. 00321 vs 003.21) * Reduced external dependencies down to Rcpp and checkmate (a very lightweight and fast function argument checker) * Bug fixes (see [github](https://github.com/jackwasey/icd9/issues?q=is%3Aissue+is%3Aclosed)) * API changes - no more validation except in the icd9IsValidXxx functions. Removed stopIfInvalidIcd9, icd9InvalidActions - internalized utility functions. They are also packaged and tested in [jwutil](http://cran.r-project.org/web/packages/jwutil/index.html) - deprecated icd9ValidXxx in favour of icd9IsValidXxx - deprecated icd9ComorbditiesXxx replacing with briefer icd9ComorbidXxx - stopped exporting benchmarking and SAS code processing. Comments and contributions very welcome via github: https://github.com/jackwasey/icd9 Jack Wasey