title: Classification of hospital patients as "surgical." Implications of the shift to ICD-9-CM.
abstract: Using a nearly complete set of hospital discharge abstracts for Michigan in 1980, the authors offer evidence that the shifts in diagnostic and procedure coding (from HICDA-2 to ICD-9-CM) and associated class definitions may have affected both estimates of surgical/nonsurgical use rates and expected lengths of stay of operated versus nonoperated patients as defined using Commission on Professional and Hospital Activities length-of-stay texts.
mesh_terms: D000043:Abstracting and Indexing; D004194:Disease / Q000145:classification*; D006801:Humans; D007902:Length of Stay; D008824:Michigan; D010351:Patient Discharge; D013514:Surgical Procedures, Operative / Q000145:classification*