Table 1. Osteoarthritis and hip/knee replacement surgeries case definitions.

Osteoarthritis (OA)
Rule:	One hospitalization or two medical visits in 365 days with an OA diagnostic code
Diagnostic codes:
ICD-9	715	Osteo-arthrosis and allied disorders
ICD-10	M15	Polyarthrosis
	M16	Coxarthrosis [arthrosis of hip]
	M17	Gonarthrosis [arthrosis of knee]
	M18	Arthrosis of first carpometacarpal joint
	M19	Other arthrosis
Exclusions:	None