What does this have to do with anything? Is it just to inject a bit of cynicism?
Because while there's certainly a lot to be gained by a bit of creativity with the coding, the first/subsequent encounter distinction is ill-suited, considering these are binary categories, and any mistakes/attempts to defraud can detected with an sQL query shorter than this paragraph.
Concerning the original question: it's basically denormalized, with the usual tradeoffs. I'd guess it's easier to double the number of codes than to add a new attribute to legacy systems.
Dx codes are a big part of my programming world, I work on medical software. Not trying to be cynical, just offering an insider perspective from someone who just helped hundreds of hospitals and thousands of agencies complete the ICD-10 switch seamlessly with no rejected 485s, no rejected 837I(5010)s or other payer rejections.
Not trying to be cynical, just trying to offer a view into the requirements set before me.
Because while there's certainly a lot to be gained by a bit of creativity with the coding, the first/subsequent encounter distinction is ill-suited, considering these are binary categories, and any mistakes/attempts to defraud can detected with an sQL query shorter than this paragraph.
Concerning the original question: it's basically denormalized, with the usual tradeoffs. I'd guess it's easier to double the number of codes than to add a new attribute to legacy systems.