The impact of new hospital orthopaedic surgery programs on total joint arthroplasty utilization.
BACKGROUND
Utilization of arthroplasty is increasing, but there are little data exploring the causes of this increase. The objective of this study was to examine the relationship between new programs for arthroplasty of the lower extremity joints and the utilization of arthroplasty.


METHODS
We identified twenty-four markets (hospital referral regions) that experienced the entry of new physician-owned specialty hospitals, using 1991 to 2005 Medicare data. We matched each market with a new specialty hospital to two different control markets (one market with a new arthroplasty program in a general hospital and one market without a new arthroplasty program), using a propensity score that accounted for market supply and demand for orthopaedic surgery and the regulatory environment. We compared the utilization of arthroplasty of the lower extremity joints (total hip arthroplasty and total knee arthroplasty) in each group of markets over a five-year window, extending from two years before to three years after the entry of new orthopaedic surgery programs.


RESULTS
The twenty-four markets with new specialty orthopaedic hospitals had higher utilization of arthroplasty at baseline (10.9 arthroplasties per 1000 Medicare beneficiaries per year) and follow-up (12.7 per 1000 beneficiaries) compared with the twenty-four markets with new arthroplasty programs in general hospitals (9.7 and 11.4, respectively) and the twenty-four markets with no new programs (9.9 and 11.3), although the differences were not significant (p > 0.05). Growth in the utilization of arthroplasty was similar in markets with new specialty hospitals before (an increase of 0.63 procedure per 1000 beneficiaries per year) and after the entry of new specialty hospitals (an increase of 0.39) compared with markets with new surgery programs in general hospitals (an increase of 0.24 before and 0.43 after) and markets with no new programs (an increase of 0.38 before and 0.33 after the entry of new specialty hospitals) (p > 0.05 for all comparisons).


CONCLUSIONS
The utilization of arthroplasty is increasing at similar rates in markets with and without new arthroplasty programs.
Lu
Xin
X
University of Iowa Carver College of Medicine, Iowa City, IA 52246, USA.
Hagen
Tyson P
TP
Vaughan-Sarrazin
Mary S
MS
Cram
Peter
P
D019644:Arthroplasty, Replacement, Hip / Q000706:statistics & numerical data*; D019645:Arthroplasty, Replacement, Knee / Q000706:statistics & numerical data*; D006782:Hospitals, Special / Q000706:statistics & numerical data*; D006801:Humans; D006278:Medicare; D015233:Models, Statistical; D009985:Orthopedics / Q000193:education* / Q000458:organization & administration; D057216:Propensity Score; D014481:United States