0
We're unable to sign you in at this time. Please try again in a few minutes.
Retry
We were able to sign you in, but your subscription(s) could not be found. Please try again in a few minutes.
Retry
There may be a problem with your account. Please contact the AMA Service Center to resolve this issue.
Contact the AMA Service Center:
Telephone: 1 (800) 262-2350 or 1 (312) 670-7827  *   Email: subscriptions@jamanetwork.com
Error Message ......
Original Contribution |

Clinical Characteristics and Outcomes of Medicare Patients Undergoing Total Hip Arthroplasty, 1991-2008 FREE

Peter Cram, MD, MBA; Xin Lu, MS; Peter J. Kaboli, MD, MS; Mary S. Vaughan-Sarrazin, PhD; Xueya Cai, PhD; Brian R. Wolf, MD, MS; Yue Li, PhD
[+] Author Affiliations

Author Affiliations: Division of General Internal Medicine, Department of Internal Medicine (Drs Cram, Kaboli, Vaughan-Sarrazin, Cai, and Li, and Ms Lu) and Department of Orthopaedic Surgery (Dr Wolf), University of Iowa Carver College of Medicine, Iowa City; CADRE (Drs Cram, Kaboli, and Vaughan-Sarrazin) and VISN 23 Midwest Rural Health Resource Center (Dr Kaboli), Iowa City Veterans Administration Medical Center, Iowa City, Iowa.


JAMA. 2011;305(15):1560-1567. doi:10.1001/jama.2011.478.
Text Size: A A A
Published online

Context Total hip arthroplasty is a common surgical procedure but little is known about longitudinal trends.

Objective To examine demographics and outcomes of patients undergoing primary and revision total hip arthroplasty.

Design, Setting, and Participants Observational cohort of 1 453 493 Medicare Part A beneficiaries who underwent primary total hip arthroplasty and 348 596 who underwent revision total hip arthroplasty. Participants were identified using International Classification of Diseases, Ninth Revision, Clinical Modification codes for primary and revision total hip arthroplasty between 1991 and 2008.

Main Outcome Measures Changes in patient demographics and comorbidity, hospital length of stay (LOS), mortality, discharge disposition, and all-cause readmission rates.

Results Between 1991 and 2008, the mean age for patients undergoing primary total hip arthroplasty increased from 74.1 to 75.1 years and for revision total hip arthroplasty from 75.8 to 77.3 years (P < .001). The mean number of comorbid illnesses per patient increased from 1.0 to 2.0 for primary total hip arthroplasty and 1.1 to 2.3 for revision (P < .001). For primary total hip arthroplasty, mean hospital LOS decreased from 9.1 days in 1991-1992 to 3.7 days in 2007-2008 (P = .002); unadjusted in-hospital and 30-day mortality decreased from 0.5% to 0.2% and from 0.7% to 0.4%, respectively (P < .001). The proportion of primary total hip arthroplasty patients discharged home declined from 68.0% to 48.2%; the proportion discharged to skilled care increased from 17.8% to 34.3%; and 30-day all-cause readmission increased from 5.9% to 8.5% (P < .001). For revision total hip arthroplasty, similar trends were observed in hospital LOS, in-hospital mortality, discharge disposition, and hospital readmission rates.

Conclusion Among Medicare beneficiaries who underwent primary and revision hip arthroplasty between 1991 and 2008, there was a decrease in hospital LOS but an increase in the rates of discharge to postacute care and readmission.

Figures in this Article

Total hip arthroplasty is a safe and effective therapy for patients with advanced degenerative joint disease.1,2 In recent years, there has been a dramatic increase in performance of this procedure both in the United States and abroad.36 There is a general assumption that increasing experience with total hip arthroplasty has resulted in improvements in patient outcomes, as has been observed in other procedures,79 but rigorous empirical data documenting such improvement are limited.1014 This lack of data are striking given that an estimated 280 000 total hip arthroplasty procedures are performed annually at a cost of more than $12 billion.5

The lack of rigorous evaluation of total hip arthroplasty outcomes is somewhat surprising given ongoing efforts to regionalize surgical procedures to higher-volume and higher-quality hospitals.1517 As a generally elective surgery, total hip arthroplasty is the type of procedure that should be amenable to regionalization. Moreover, the introduction of the Medicare prospective payment system in 1983 provided incentive to hospitals to control costs.18,19 A particularly important cost-control mechanism has been through reducing hospital length of stay (LOS). However, there is growing concern that hospitals may be reducing LOS by discharging patients prematurely, resulting in increased use of skilled-care facilities20,21 and increased patient readmissions, thus eliminating much of the cost savings originally envisioned by the prospective payment system.22,23

The objective of this study was to evaluate long-term trends in the outcomes of Medicare beneficiaries undergoing primary and revision total hip arthroplasty and to explore whether reductions in hospital LOS might be associated with increased discharge of patients to postacute care settings, increased readmission rates, or a combination of both outcomes.

Data

We used Medicare Provider Analysis and Review (MedPAR) Part A data files to identify fee-for-service beneficiaries who underwent primary or revision total hip arthroplasty between 1991 and 2008. Patients were identified using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes (81.51 for primary total hip arthroplasty and 80.05, 81.53, 00.70, 00.71, 00.72, and 00.73 for revision total hip arthroplasty).2427 The Part A files contain a range of data collected from discharge abstracts for all hospitalized fee-for-service Medicare enrollees including patient demographics, ICD-9-CM codes for primary and secondary diagnoses and procedures, admission source (eg, emergency department or transfer from outside hospital), admission and discharge dates, discharge disposition (coded as 25 separate categories), death occurring as many as 3 years after discharge, a unique patient identifier that allows for identification of patient readmissions, and each hospital's unique 6-digit identification number.

For purposes of this analysis, patient race was categorized as white, black, other, and not available. Comorbid illnesses present on the index admission were identified using algorithms described by Elixhauser et al28,29 that consider 30 specific conditions and exclude comorbid conditions that may represent complications of care or that are related to the primary reason for hospitalization.

To perform our 18-year longitudinal study, we used 2 separate Medicare Part A data files obtained from the Centers for Medicare & Medicaid Services (1 file detailed 1991-2005; 1 file 2006-2008). Each of these files contains an internally consistent unique patient identifier that allows for the tracking of individual patients across time within the file. However, because the unique patient identifiers differ across the 2 different data files, it was impossible to link individual patients across the 2 different files. Thus, for example, if a single patient were hospitalized in December 2005 and readmitted again in January 2006, the lack of a consistent unique identifier across the 2 files precluded us from determining whether a single patient were admitted and readmitted or whether 2 different patients were admitted (one in December 2005 and another in January 2006). From a practical standpoint, this had minimal impact on our results but did influence our methodological approach, as described further.

Our intention was to examine changes in outcomes of patients undergoing primary and revision total hip arthroplasty procedures. Because primary total hip arthroplasty is most often an elective procedure while revision total hip arthroplasty can be either an elective or more urgent procedure, we applied separate exclusion criteria to the primary and revision total hip arthroplasty populations in accordance with prior studies.27,30,31 For primary total hip arthroplasty we sequentially excluded patients with acute fractures (136 887), patients admitted through the emergency department (19 721), and patients admitted after transfer from another acute-care hospital (2856); these exclusion criteria were developed to select a population of primary elective total hip arthroplasty patients. Our revision total hip arthroplasty population did not exclude these types of patients because revision total hip arthroplasty is often an emergent or unscheduled procedure. This study was approved by the University of Iowa Institutional Review Board.

Outcomes of Interest

Our outcomes of interest included hospital length of stay (LOS), mortality (in-hospital, within 30 and 90 days of admission), discharge disposition, and all-cause readmission within 30 days and 90 days of admission. Discharge disposition was stratified into 6 mutually exclusive categories: home; skilled care/intermediate care; transfer to another acute-care hospital; inpatient rehabilitation; dead; and other. We limited our 30-day readmission analysis to patients whose index hospitalization occurred prior to November 30, 2005, for procedures performed between 1991 and 2005, and prior to November 30, 2008, for procedures performed between 2006 and 2008, to allow for a full 30-day follow-up period. Similarly, our 90-day readmission analysis was limited to patients whose index hospitalization occurred prior to September 30, 2005, for procedures performed between 1991 and 2005, and prior to September 30, 2008, for procedures performed between 2006 and 2008. Patients with hospital LOS longer than 1 year were excluded from the LOS analysis in accordance with other recent studies.22

Statistical Analysis

We examined the demographic characteristics and prevalence of key comorbid illnesses for patients who underwent total hip arthroplasty during the study period; for simplicity, data are presented separately for each 2-year period (eg, 1991-1992, 1993-1994, etc). We used analysis of variance for comparisons of continuous variables and the Mantel-Haenszel χ2 test for categorical variables. All analyses were performed separately for primary and revision total hip arthroplasty patients.

We compared rates of each of the outcomes described previously for each of the 2-year periods using similar statistical methods. We used graphical techniques to examine changes in LOS, mortality, discharge disposition, and readmission rates over the course of the study period. To account for the changing demographics of the primary and revision total hip arthroplasty populations over time, we calculated risk-standardized mortality ratios that adjusted for age, sex, and race.32 Inclusion of patient demographics in calculating these rates is important given that prior studies have demonstrated differential complication and use rates for joint arthroplasty among different demographic groups.3335 All analyses for these variables were conducted separately for the primary and revision total hip arthroplasty cohorts.

All P values were 2-tailed, with P values less than .05 considered statistically significant. All statistical analyses were performed using SAS version 9.2 (SAS Institute Inc, Cary, North Carolina).

Sensitivity Analysis

To assess the robustness of our results, we performed 2 supplemental analyses. First, we repeated our analyses while restricting our analysis to the first primary or first revision hip arthroplasty procedure performed on each patient during a 12-month period; this eliminates patients who undergo “staged” bilateral arthroplasty procedures or complicated revisions. Second, we repeated our analyses after adding back the excluded populations described previously (eg, fracture patients) (eFigure 1 and eFigure 2).

Our final study population included 1 453 493 elective primary total hip arthroplasty procedures and 348 596 revision hip arthroplasty procedures performed on Medicare beneficiaries between 1991 and 2008. For primary total hip arthroplasty comparing 1991-1992 and 2007-2008 (Table 1), mean (standard deviation [SD]) age increased from 74.1 (6.0) years (95% confidence interval [CI], 74.0-74.1) to 75.1 (6.5) years (95% CI, 75.1-75.2) (P = .01); and diabetes prevalence increased from 7.1% (95% CI, 7.0%-7.3%) to 15.5% (95% CI, 15.4%-15.7%), and obesity prevalence increased from 2.2% (95% CI, 2.2%-2.3%) to 7.6% (95% CI, 7.5%-7.7%) (P < .001 for each), respectively.

Table Graphic Jump LocationTable 1. Characteristics of Medicare Beneficiaries Receiving Primary Total Hip Arthroplasty, 1991-2008

Trends were similar for revision total hip arthroplasty comparing 1991-1992 and 2007-2008 (Table 2). In particular, mean (SD) age increased from 75.8 (6.9) years (95% CI, 75.7-75.9) to 77.3 (7.2) years (95% CI, 77.2-77.4), diabetes prevalence increased from 7.2% (95% CI, 6.9%-7.4%) to 15.7% (95% CI, 15.3%-16.0%), and obesity prevalence increased from 1.4% (95% CI, 1.3%-1.5%) to 4.7% (95% CI, 4.5%-4.9%) (P < .001 for each), respectively.

Table Graphic Jump LocationTable 2. Characteristics of Medicare Beneficiaries Receiving Revision Total Hip Arthroplasty, 1991-2008

For primary total hip arthroplasty comparing 1991-1992 and 2007-2008, mean hospital LOS decreased from 9.1 days (95% CI, 9.1-9.2) to 3.7 days (95% CI, 3.7-3.7) (Table 3 and Figure 1), a 59.3% relative decline (P < .001); in-hospital mortality after primary total hip arthroplasty decreased from 0.5% (95% CI, 0.5%-0.5%) to 0.2% (95% CI, 0.2%-0.2%), a 60.0% relative reduction (P < .001); 30-day mortality decreased from 0.7% (95% CI, 0.7%-0.7%) to 0.4% (95% CI, 0.4%-0.4%), a 42.9% relative reduction (P = .004); and 90-day mortality decreased from 1.2% (95% CI, 1.2%-1.3%) to 0.8% (95% CI, 0.7%-0.8%) (P < .001), respectively. After adjustment for patient characteristics, risk-adjusted 30-day mortality over the study period decreased from 0.7% (95% CI, 0.7%-0.8%) to 0.3% (95% CI, 0.3%-0.4%) and 90-day mortality decreased from 1.3% (95% CI, 1.2%-1.3%) to 0.7% (95% CI, 0.7%-0.7%) (P < .001 for each).

Table Graphic Jump LocationTable 3. Unadjusted Hospital LOS, Discharge Disposition, Mortality, and Readmission Rates for Primary Total Hip Arthroplasty
Place holder to copy figure label and caption
Figure 1. Trends in Hospital Length of Stay, Discharge Disposition, Mortality, and Readmission Rates for Primary Total Hip Arthroplasty 1991-2008
Graphic Jump Location

For clarity, discharge dispositions of in-hospital death and other are not shown. Error bars indicate 95% confidence intervals. For mortality, error bars are shown for adjusted data only. See Table 3 for data.

The proportion of primary total hip arthroplasty patients discharged to home decreased from 68.0% (95% CI, 67.8%-68.3%) (P < .001) in 1991-1992 to 48.2% (95% CI, 48.0%-48.5%) in 2007-2008, while the proportion of patients discharged to skilled or intermediate care increased from 17.8% (95% CI, 17.6%-18.1%) to 34.3% (95% CI, 34.1%-34.5%) (P < .001) (Table 3 and Figure 1). The 30-day all-cause readmission rate decreased from 5.9% (95% CI, 5.8%-6.1%) in 1991-1992 to 4.6% (95% CI, 4.5%-4.7%) in 2001-2002 (P < .001), before increasing to 8.5% (95% CI, 8.4%-8.6%) in 2007-2008 (P < .001)—results were similar for 90-day readmission rates.

For revision total hip arthroplasty, mean hospital LOS decreased from 12.3 days (95% CI, 12.2-12.4) in 1991-1992 to 6.0 days (95% CI, 6.0-6.1) in 2007-2008 (Table 4 and Figure 2), a 51.2% relative decline (P < .001). Unadjusted in-hospital mortality after revision total hip arthroplasty decreased from 1.8% (95% CI, 1.6%-1.9%) in 1991-1992 to 1.2% (95% CI, 1.1%-1.3%) in 2007-2008, a 33.3% relative reduction (P < .001). Conversely, during the study period, unadjusted 30-day mortality increased from 2.0% (95% CI, 1.8%-2.1%) in 1991-1992 to 2.4% (95% CI, 2.2%-2.5%) in 2007-2008, a 20.0% relative increase (P = .004), and 90-day mortality increased from 4.0% (95% CI, 3.8%-4.2%) to 5.2% (95% CI, 5.0%-5.4%), a 30.0% relative increase (P < .001). However, after adjustment for patient characteristics, risk-adjusted 30-day mortality remained stable within a narrow range between 1.9% and 2.3% (P = .22), while adjusted 90-day mortality remained near 4.5% throughout the study period (P = .16).

Table Graphic Jump LocationTable 4. Unadjusted Hospital LOS, Discharge Disposition, Mortality, and Readmission Rates for Revision Total Hip Arthroplasty
Place holder to copy figure label and caption
Figure 2. Trends in Hospital Length of Stay, Discharge Disposition, Mortality, and Readmission Rates for Revision Total Hip Arthroplasty 1991-2008
Graphic Jump Location

For clarity, discharge dispositions of in-hospital death and other are not shown. Error bars indicate 95% confidence intervals. For mortality, error bars are shown for adjusted data only. See Table 4 for data.

The proportion of revision total hip arthroplasty patients discharged to home decreased from 57.4% (95% CI, 56.8%-57.9%) in 1991-1992 to 35.4% (95% CI, 34.9%-35.8%) in 2007-2008 (P < .001), while the proportion of patients discharged to skilled or intermediate care increased from 26.7% (95% CI, 26.2%-27.1%) to 42.4% (95% CI, 42.0%-42.9%) (P < .001) (Table 4 and Figure 2). The 30-day all-cause readmission rate decreased from 8.7% (95% CI, 8.3%-9.0%) in 1991-1992 to 8.2% (95% CI, 7.9%-8.5%) in 1999-2000 (P < .001), before increasing to 14.1% (95% CI, 13.8%-14.5%) in 2007-2008 (P < .001), with similar results for 90-day readmission rates.

In an analysis of 1991-2008 Medicare administrative data, 3 trends were identified. First, we found that despite increasing patient complexity, both unadjusted and adjusted mortality for primary total hip arthroplasty showed substantial improvement over time. Conversely, our second finding was that for revision total hip arthroplasty, unadjusted mortality appeared to increase modestly but this increase was largely explained by increasing patient complexity. Third and most importantly, marked declines in hospital LOS for both primary and revision total hip arthroplasty seemed to correspond with an increase in the proportion of patients who were discharged to postacute care and an increase in patient readmissions.

A number of our findings warrant further discussion. First, we found increasing complexity of both primary and revision total hip arthroplasty patients. Although a number of studies have documented increasing complexity of patients in the cardiovascular disease literature,22,23,36 few studies have evaluated trends in patient complexity in orthopedics and most have focused on knee arthroplasty.3740 Our finding of an increase in the mean age of both primary and revision total hip arthroplasty patients suggests that at least some of the increase in patient complexity is real and is not simply an artifact of more aggressive coding practices (ie, upcoding).41

Our finding of increased patient complexity is particularly important when considering the changes in patient mortality that were observed. We found clinically and statistically significant reductions in primary total hip arthroplasty mortality, albeit from very low baseline levels. Conversely, the finding of an increase in revision total hip arthroplasty mortality in unadjusted analyses was somewhat unexpected; the finding that this increase in mortality was no longer significant in adjusted analyses is reassuring. The absence of similar large-scale studies of the US hip arthroplasty population with which to compare our results highlights the need for more rigorous study of total hip arthroplasty outcomes.

Second, the marked decrease in hospital LOS for both primary and revision total hip arthroplasty may have policy implications. The motivation for hospitals to reduce LOS under the Medicare prospective payment system has been well described,42,43 but the impact of declining LOS is much less clear. While Bueno et al22 noted that reductions in LOS for Medicare beneficiaries hospitalized with congestive heart failure were accompanied by an increase in readmission rates, a prior study by Baker et al44 found that reductions in LOS were not associated with an increase in readmissions. To the best of our knowledge, no prior studies have evaluated associations with reduction in LOS in regard to joint arthroplasty.

We found that the reduction in hospital LOS in both primary and revision total hip arthroplasty patients was accompanied by a significant increase in the proportion of patients discharged to postacute care facilities (ie, nursing homes and rehabilitation centers), and a significant reduction in the proportion of patients discharged directly home. Moreover, we found that while the reduction in hospital LOS was not associated with an increase in readmission rates between 1992 and 1999, in more recent years, readmission rates have risen markedly. These findings reinforce the potential wisdom of moving to bundled payments, reimbursing for episodes of care, or a combination of both as a way for incentivizing the correct LOS, rather than perpetual reductions in LOS that seem to be occurring.

Our study has limitations that warrant brief mention. First, our study was limited to fee-for-service Medicare beneficiaries and thus extrapolation to other populations should be done with caution. That said, more than 60% of all total hip arthroplasty procedures are performed on Medicare enrollees, making this an appropriate data set for studying total hip arthroplasty. Second, our study relied upon administrative data and thus we were unable to evaluate some important arthroplasty outcomes including functional status and patient satisfaction.

In conclusion, mortality after primary total hip arthroplasty has declined moderately over time and mortality after revision total hip arthroplasty has remained stable despite substantial increases in patient complexity. There have also been marked reductions in hospital LOS and rising readmission rates.

Corresponding Author: Peter Cram, MD, MBA, Division of General Medicine, University of Iowa Carver College of Medicine, Iowa City VA Medical Center, Mail Stop 152, Iowa City, IA 52242 (peter-cram@uiowa.edu).

Author Contributions: Dr Cram and Ms Lu had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Cram, Lu, Wolf, Li.

Acquisition of data: Cram, Vaughan-Sarrazin, Cai.

Analysis and interpretation of data: Cram, Lu, Kaboli, Vaughan-Sarrazin, Li.

Drafting of the manuscript: Cram, Lu.

Critical revision of the manuscript for important intellectual content: Cram, Lu, Kaboli, Vaughan-Sarrazin, Cai, Wolf, Li.

Statistical analysis: Cram, Lu, Cai.

Obtained funding: Cram.

Administrative, technical, or material support: Lu, Wolf.

Study supervision: Vaughan-Sarrazin.

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest and none were reported.

Funding/Support: Dr Cram was supported by a K23 career development award (RR01997201) from the National Center for Research Resources at the National Institutes of Health (NIH), and the Robert Wood Johnson Physician Faculty Scholars Program. The National Heart, Lung, and Blood Institute at NIH also provided support to Dr Cram (R01 HL085347-01A1) and Dr Li (R01 AG033202).

Role of the Sponsor: The National Center for Research Resources at NIH and the Robert Wood Johnson Physician Faculty Scholars Program had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript.

Conflict of Interest: The authors report no conflicts of interest. Dr Cram reports having received consulting fees from The Consumers Union (publisher of Consumer Reports magazine) and Vanguard Health Inc for advice provided on quality improvement initiatives.

Disclaimer: The views expressed in this article are those of the authors and do not necessarily represent the views of the US Department of Veterans Affairs.

Chang RW, Pellisier JM, Hazen GB. A cost-effectiveness analysis of total hip arthroplasty for osteoarthritis of the hip.  JAMA. 1996;275(11):858-865
PubMed   |  Link to Article
Katz JN, Phillips CB, Baron JA,  et al.  Association of hospital and surgeon volume of total hip replacement with functional status and satisfaction three years following surgery.  Arthritis Rheum. 2003;48(2):560-568
PubMed   |  Link to Article
Merx H, Dreinhöfer K, Schräder P,  et al.  International variation in hip replacement rates.  Ann Rheum Dis. 2003;62(3):222-226
PubMed   |  Link to Article
Lohmander LS, Engesaeter LB, Herberts P, Ingvarsson T, Lucht U, Puolakka TJ. Standardized incidence rates of total hip replacement for primary hip osteoarthritis in the 5 Nordic countries: similarities and differences.  Acta Orthop. 2006;77(5):733-740
PubMed   |  Link to Article
National Center for Health Statistics.  Health, United States, 2009: with special feature on medical technology. Centers for Disease Control and Prevention Web site. http://www.cdc.gov/nchs/data/hus/hus09.pdf. Accessed March 28, 2011
Kurtz S, Mowat F, Ong K, Chan N, Lau E, Halpern M. Prevalence of primary and revision total hip and knee arthroplasty in the United States from 1990 through 2002.  J Bone Joint Surg Am. 2005;87(7):1487-1497
PubMed   |  Link to Article
Venkitachalam L, Kip KE, Selzer F,  et al; Investigators of NHLBI-sponsored, multicenter 1985-1986 PTCA and 1997-2006 Dynamic Registries.  Twenty-year evolution of percutaneous coronary intervention and its impact on clinical outcomes: a report from the National Heart, Lung, and Blood Institute-sponsored, multicenter 1985-1986 PTCA and 1997-2006 Dynamic Registries.  Circ Cardiovasc Interv. 2009;2(1):6-13
PubMed   |  Link to Article
Ryan J, Linde-Zwirble W, Engelhart L, Cooper L, Cohen DJ. Temporal changes in coronary revascularization procedures, outcomes, and costs in the bare-metal stent and drug-eluting stent eras: results from the US Medicare program.  Circulation. 2009;119(7):952-961
PubMed   |  Link to Article
Birkmeyer NJ, Marrin CA, Morton JR,  et al; Northern New England Cardiovascular Disease Study Group.  Decreasing mortality for aortic and mitral valve surgery in Northern New England.  Ann Thorac Surg. 2000;70(2):432-437
PubMed   |  Link to Article
Birrell F, Johnell O, Silman A. Projecting the need for hip replacement over the next three decades: influence of changing demography and threshold for surgery.  Ann Rheum Dis. 1999;58(9):569-572
PubMed   |  Link to Article
Huo MH, Parvizi J, Bal BS, Mont MA.Council of Musculoskeletal Specialty Societies (COMSS) of the American Academy of Orthopaedic Surgeons.  What's new in total hip arthroplasty.  J Bone Joint Surg Am. 2008;90(9):2043-2055
PubMed   |  Link to Article
Schrama JC, Espehaug B, Hallan G,  et al.  Risk of revision for infection in primary total hip and knee arthroplasty in patients with rheumatoid arthritis compared with osteoarthritis: a prospective, population-based study on 108 786 hip and knee joint arthroplasties from the Norwegian Arthroplasty Register.  Arthritis Care Res (Hoboken). 2010;62(4):473-479
PubMed   |  Link to Article
Himanen AK, Belt E, Nevalainen J, Hämäläinen M, Lehto MU. Survival of the AGC total knee arthroplasty is similar for arthrosis and rheumatoid arthritis: Finnish Arthroplasty Register report on 8467 operations carried out between 1985 and 1999.  Acta Orthop. 2005;76(1):85-88
PubMed   |  Link to Article
Lie SA, Engesaeter LB, Havelin LI, Gjessing HK, Vollset SE. Mortality after total hip replacement: 0-10-year follow-up of 39 543 patients in the Norwegian Arthroplasty Register.  Acta Orthop Scand. 2000;71(1):19-27
PubMed   |  Link to Article
Ricciardi R, Virnig BA, Ogilvie JW Jr, Dahlberg PS, Selker HP, Baxter NN. Volume-outcome relationship for coronary artery bypass grafting in an era of decreasing volume.  Arch Surg. 2008;143(4):338-344
PubMed   |  Link to Article
Ho V, Town RJ, Heslin MJ. Regionalization versus competition in complex cancer surgery.  Health Econ Policy Law. 2007;2(pt 1):51-71
PubMed   |  Link to Article
Birkmeyer JD, Siewers AE, Marth NJ, Goodman DC. Regionalization of high-risk surgery and implications for patient travel times.  JAMA. 2003;290(20):2703-2708
PubMed   |  Link to Article
Zwanziger J, Melnick GA. The effects of hospital competition and the Medicare prospective payment system program on hospital cost behavior in California.  J Health Econ. 1988;7(4):301-320
Link to Article
Sloan FA, Morrisey MA, Valvona J. Effects of the Medicare prospective payment system on hospital cost containment: an early appraisal.  Milbank Q. 1988;66(2):191-220
PubMed   |  Link to Article
Buntin MB, Colla CH, Escarce JJ. Effects of payment changes on trends in post-acute care.  Health Serv Res. 2009;44(4):1188-1210
PubMed   |  Link to Article
Liu K, Baseggio C, Wissoker D, Maxwell S, Haley J, Long S. Long-term care hospitals under Medicare: facility-level characteristics.  Health Care Financ Rev. 2001;23(2):1-18
PubMed
Bueno H, Ross JS, Wang Y,  et al.  Trends in length of stay and short-term outcomes among Medicare patients hospitalized for heart failure, 1993-2006.  JAMA. 2010;303(21):2141-2147
PubMed   |  Link to Article
Ross JS, Chen J, Lin Z,  et al.  Recent national trends in readmission rates after heart failure hospitalization.  Circ Heart Fail. 2010;3(1):97-103
PubMed   |  Link to Article
Mitchell JB, Bubolz T, Paul JE,  et al.  Using Medicare claims for outcomes research.  Med Care. 1994;32(7):(suppl)  JS38-JS51
PubMed
Katz JN, Barrett J, Mahomed NN, Baron JA, Wright RJ, Losina E. Association between hospital and surgeon procedure volume and the outcomes of total knee replacement.  J Bone Joint Surg Am. 2004;86-A(9):1909-1916
PubMed
Losina E, Barrett J, Mahomed NN, Baron JA, Katz JN. Early failures of total hip replacement: effect of surgeon volume.  Arthritis Rheum. 2004;50(4):1338-1343
PubMed   |  Link to Article
Katz JN, Losina E, Barrett J,  et al.  Association between hospital and surgeon procedure volume and outcomes of total hip replacement in the United States Medicare population.  J Bone Joint Surg Am. 2001;83-A(11):1622-1629
PubMed
Elixhauser A, Steiner C, Harris DR, Coffey RM. Comorbidity measures for use with administrative data.  Med Care. 1998;36(1):8-27
PubMed   |  Link to Article
Quan H, Sundararajan V, Halfon P,  et al.  Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data.  Med Care. 2005;43(11):1130-1139
PubMed   |  Link to Article
Hagen TP, Vaughan-Sarrazin MS, Cram P. Relation between hospital orthopaedic specialisation and outcomes in patients aged 65 and older: retrospective analysis of US Medicare data.  BMJ. 2010;340:c165
PubMed   |  Link to Article
Cram P, Vaughan-Sarrazin MS, Wolf B, Katz JN, Rosenthal GE. A comparison of total hip and knee replacement in specialty and general hospitals.  J Bone Joint Surg Am. 2007;89(8):1675-1684
PubMed   |  Link to Article
Shahian DM, Torchiana DF, Shemin RJ, Rawn JD, Normand SL. Massachusetts cardiac surgery report card: implications of statistical methodology.  Ann Thorac Surg. 2005;80(6):2106-2113
PubMed   |  Link to Article
Skinner J, Weinstein JN, Sporer SM, Wennberg JE. Racial, ethnic, and geographic disparities in rates of knee arthroplasty among Medicare patients.  N Engl J Med. 2003;349(14):1350-1359
PubMed   |  Link to Article
Escalante A, Barrett J, del Rincón I, Cornell JE, Phillips CB, Katz JN. Disparity in total hip replacement affecting Hispanic Medicare beneficiaries.  Med Care. 2002;40(6):451-460
PubMed   |  Link to Article
Hausmann LR, Mor M, Hanusa BH,  et al.  The effect of patient race on total joint replacement recommendations and utilization in the orthopedic setting.  J Gen Intern Med. 2010;25(9):982-988
PubMed   |  Link to Article
Krumholz HM, Wang Y, Chen J,  et al.  Reduction in acute myocardial infarction mortality in the United States: risk-standardized mortality rates from 1995-2006.  JAMA. 2009;302(7):767-773
PubMed   |  Link to Article
Jain NB, Higgins LD, Ozumba D,  et al.  Trends in epidemiology of knee arthroplasty in the United States, 1990-2000.  Arthritis Rheum. 2005;52(12):3928-3933
PubMed   |  Link to Article
Robertsson O, Dunbar MJ, Knutson K, Lidgren L. Past incidence and future demand for knee arthroplasty in Sweden: a report from the Swedish Knee Arthroplasty Register regarding the effect of past and future population changes on the number of arthroplasties performed.  Acta Orthop Scand. 2000;71(4):376-380
PubMed   |  Link to Article
Mehrotra C, Remington PL, Naimi TS, Washington W, Miller R. Trends in total knee replacement surgeries and implications for public health, 1990-2000.  Public Health Rep. 2005;120(3):278-282
PubMed
Khatod M, Inacio M, Paxton EW,  et al.  Knee replacement: epidemiology, outcomes, and trends in Southern California: 17 080 replacements from 1995 through 2004.  Acta Orthop. 2008;79(6):812-819
PubMed   |  Link to Article
Silverman E, Skinner J. Medicare upcoding and hospital ownership.  J Health Econ. 2004;23(2):369-389
PubMed   |  Link to Article
Davis C, Rhodes DJ. The impact of DRGs on the cost and quality of health care in the United States.  Health Policy. 1988;9(2):117-131
PubMed   |  Link to Article
Chulis GS. Assessing Medicare's prospective payment system for hospitals.  Med Care Rev. 1991;48(2):167-206
PubMed   |  Link to Article
Baker DW, Einstadter D, Husak SS, Cebul RD. Trends in postdischarge mortality and readmissions: has length of stay declined too far?  Arch Intern Med. 2004;164(5):538-544
PubMed   |  Link to Article

Figures

Place holder to copy figure label and caption
Figure 1. Trends in Hospital Length of Stay, Discharge Disposition, Mortality, and Readmission Rates for Primary Total Hip Arthroplasty 1991-2008
Graphic Jump Location

For clarity, discharge dispositions of in-hospital death and other are not shown. Error bars indicate 95% confidence intervals. For mortality, error bars are shown for adjusted data only. See Table 3 for data.

Place holder to copy figure label and caption
Figure 2. Trends in Hospital Length of Stay, Discharge Disposition, Mortality, and Readmission Rates for Revision Total Hip Arthroplasty 1991-2008
Graphic Jump Location

For clarity, discharge dispositions of in-hospital death and other are not shown. Error bars indicate 95% confidence intervals. For mortality, error bars are shown for adjusted data only. See Table 4 for data.

Tables

Table Graphic Jump LocationTable 1. Characteristics of Medicare Beneficiaries Receiving Primary Total Hip Arthroplasty, 1991-2008
Table Graphic Jump LocationTable 2. Characteristics of Medicare Beneficiaries Receiving Revision Total Hip Arthroplasty, 1991-2008
Table Graphic Jump LocationTable 3. Unadjusted Hospital LOS, Discharge Disposition, Mortality, and Readmission Rates for Primary Total Hip Arthroplasty
Table Graphic Jump LocationTable 4. Unadjusted Hospital LOS, Discharge Disposition, Mortality, and Readmission Rates for Revision Total Hip Arthroplasty

References

Chang RW, Pellisier JM, Hazen GB. A cost-effectiveness analysis of total hip arthroplasty for osteoarthritis of the hip.  JAMA. 1996;275(11):858-865
PubMed   |  Link to Article
Katz JN, Phillips CB, Baron JA,  et al.  Association of hospital and surgeon volume of total hip replacement with functional status and satisfaction three years following surgery.  Arthritis Rheum. 2003;48(2):560-568
PubMed   |  Link to Article
Merx H, Dreinhöfer K, Schräder P,  et al.  International variation in hip replacement rates.  Ann Rheum Dis. 2003;62(3):222-226
PubMed   |  Link to Article
Lohmander LS, Engesaeter LB, Herberts P, Ingvarsson T, Lucht U, Puolakka TJ. Standardized incidence rates of total hip replacement for primary hip osteoarthritis in the 5 Nordic countries: similarities and differences.  Acta Orthop. 2006;77(5):733-740
PubMed   |  Link to Article
National Center for Health Statistics.  Health, United States, 2009: with special feature on medical technology. Centers for Disease Control and Prevention Web site. http://www.cdc.gov/nchs/data/hus/hus09.pdf. Accessed March 28, 2011
Kurtz S, Mowat F, Ong K, Chan N, Lau E, Halpern M. Prevalence of primary and revision total hip and knee arthroplasty in the United States from 1990 through 2002.  J Bone Joint Surg Am. 2005;87(7):1487-1497
PubMed   |  Link to Article
Venkitachalam L, Kip KE, Selzer F,  et al; Investigators of NHLBI-sponsored, multicenter 1985-1986 PTCA and 1997-2006 Dynamic Registries.  Twenty-year evolution of percutaneous coronary intervention and its impact on clinical outcomes: a report from the National Heart, Lung, and Blood Institute-sponsored, multicenter 1985-1986 PTCA and 1997-2006 Dynamic Registries.  Circ Cardiovasc Interv. 2009;2(1):6-13
PubMed   |  Link to Article
Ryan J, Linde-Zwirble W, Engelhart L, Cooper L, Cohen DJ. Temporal changes in coronary revascularization procedures, outcomes, and costs in the bare-metal stent and drug-eluting stent eras: results from the US Medicare program.  Circulation. 2009;119(7):952-961
PubMed   |  Link to Article
Birkmeyer NJ, Marrin CA, Morton JR,  et al; Northern New England Cardiovascular Disease Study Group.  Decreasing mortality for aortic and mitral valve surgery in Northern New England.  Ann Thorac Surg. 2000;70(2):432-437
PubMed   |  Link to Article
Birrell F, Johnell O, Silman A. Projecting the need for hip replacement over the next three decades: influence of changing demography and threshold for surgery.  Ann Rheum Dis. 1999;58(9):569-572
PubMed   |  Link to Article
Huo MH, Parvizi J, Bal BS, Mont MA.Council of Musculoskeletal Specialty Societies (COMSS) of the American Academy of Orthopaedic Surgeons.  What's new in total hip arthroplasty.  J Bone Joint Surg Am. 2008;90(9):2043-2055
PubMed   |  Link to Article
Schrama JC, Espehaug B, Hallan G,  et al.  Risk of revision for infection in primary total hip and knee arthroplasty in patients with rheumatoid arthritis compared with osteoarthritis: a prospective, population-based study on 108 786 hip and knee joint arthroplasties from the Norwegian Arthroplasty Register.  Arthritis Care Res (Hoboken). 2010;62(4):473-479
PubMed   |  Link to Article
Himanen AK, Belt E, Nevalainen J, Hämäläinen M, Lehto MU. Survival of the AGC total knee arthroplasty is similar for arthrosis and rheumatoid arthritis: Finnish Arthroplasty Register report on 8467 operations carried out between 1985 and 1999.  Acta Orthop. 2005;76(1):85-88
PubMed   |  Link to Article
Lie SA, Engesaeter LB, Havelin LI, Gjessing HK, Vollset SE. Mortality after total hip replacement: 0-10-year follow-up of 39 543 patients in the Norwegian Arthroplasty Register.  Acta Orthop Scand. 2000;71(1):19-27
PubMed   |  Link to Article
Ricciardi R, Virnig BA, Ogilvie JW Jr, Dahlberg PS, Selker HP, Baxter NN. Volume-outcome relationship for coronary artery bypass grafting in an era of decreasing volume.  Arch Surg. 2008;143(4):338-344
PubMed   |  Link to Article
Ho V, Town RJ, Heslin MJ. Regionalization versus competition in complex cancer surgery.  Health Econ Policy Law. 2007;2(pt 1):51-71
PubMed   |  Link to Article
Birkmeyer JD, Siewers AE, Marth NJ, Goodman DC. Regionalization of high-risk surgery and implications for patient travel times.  JAMA. 2003;290(20):2703-2708
PubMed   |  Link to Article
Zwanziger J, Melnick GA. The effects of hospital competition and the Medicare prospective payment system program on hospital cost behavior in California.  J Health Econ. 1988;7(4):301-320
Link to Article
Sloan FA, Morrisey MA, Valvona J. Effects of the Medicare prospective payment system on hospital cost containment: an early appraisal.  Milbank Q. 1988;66(2):191-220
PubMed   |  Link to Article
Buntin MB, Colla CH, Escarce JJ. Effects of payment changes on trends in post-acute care.  Health Serv Res. 2009;44(4):1188-1210
PubMed   |  Link to Article
Liu K, Baseggio C, Wissoker D, Maxwell S, Haley J, Long S. Long-term care hospitals under Medicare: facility-level characteristics.  Health Care Financ Rev. 2001;23(2):1-18
PubMed
Bueno H, Ross JS, Wang Y,  et al.  Trends in length of stay and short-term outcomes among Medicare patients hospitalized for heart failure, 1993-2006.  JAMA. 2010;303(21):2141-2147
PubMed   |  Link to Article
Ross JS, Chen J, Lin Z,  et al.  Recent national trends in readmission rates after heart failure hospitalization.  Circ Heart Fail. 2010;3(1):97-103
PubMed   |  Link to Article
Mitchell JB, Bubolz T, Paul JE,  et al.  Using Medicare claims for outcomes research.  Med Care. 1994;32(7):(suppl)  JS38-JS51
PubMed
Katz JN, Barrett J, Mahomed NN, Baron JA, Wright RJ, Losina E. Association between hospital and surgeon procedure volume and the outcomes of total knee replacement.  J Bone Joint Surg Am. 2004;86-A(9):1909-1916
PubMed
Losina E, Barrett J, Mahomed NN, Baron JA, Katz JN. Early failures of total hip replacement: effect of surgeon volume.  Arthritis Rheum. 2004;50(4):1338-1343
PubMed   |  Link to Article
Katz JN, Losina E, Barrett J,  et al.  Association between hospital and surgeon procedure volume and outcomes of total hip replacement in the United States Medicare population.  J Bone Joint Surg Am. 2001;83-A(11):1622-1629
PubMed
Elixhauser A, Steiner C, Harris DR, Coffey RM. Comorbidity measures for use with administrative data.  Med Care. 1998;36(1):8-27
PubMed   |  Link to Article
Quan H, Sundararajan V, Halfon P,  et al.  Coding algorithms for defining comorbidities in ICD-9-CM and ICD-10 administrative data.  Med Care. 2005;43(11):1130-1139
PubMed   |  Link to Article
Hagen TP, Vaughan-Sarrazin MS, Cram P. Relation between hospital orthopaedic specialisation and outcomes in patients aged 65 and older: retrospective analysis of US Medicare data.  BMJ. 2010;340:c165
PubMed   |  Link to Article
Cram P, Vaughan-Sarrazin MS, Wolf B, Katz JN, Rosenthal GE. A comparison of total hip and knee replacement in specialty and general hospitals.  J Bone Joint Surg Am. 2007;89(8):1675-1684
PubMed   |  Link to Article
Shahian DM, Torchiana DF, Shemin RJ, Rawn JD, Normand SL. Massachusetts cardiac surgery report card: implications of statistical methodology.  Ann Thorac Surg. 2005;80(6):2106-2113
PubMed   |  Link to Article
Skinner J, Weinstein JN, Sporer SM, Wennberg JE. Racial, ethnic, and geographic disparities in rates of knee arthroplasty among Medicare patients.  N Engl J Med. 2003;349(14):1350-1359
PubMed   |  Link to Article
Escalante A, Barrett J, del Rincón I, Cornell JE, Phillips CB, Katz JN. Disparity in total hip replacement affecting Hispanic Medicare beneficiaries.  Med Care. 2002;40(6):451-460
PubMed   |  Link to Article
Hausmann LR, Mor M, Hanusa BH,  et al.  The effect of patient race on total joint replacement recommendations and utilization in the orthopedic setting.  J Gen Intern Med. 2010;25(9):982-988
PubMed   |  Link to Article
Krumholz HM, Wang Y, Chen J,  et al.  Reduction in acute myocardial infarction mortality in the United States: risk-standardized mortality rates from 1995-2006.  JAMA. 2009;302(7):767-773
PubMed   |  Link to Article
Jain NB, Higgins LD, Ozumba D,  et al.  Trends in epidemiology of knee arthroplasty in the United States, 1990-2000.  Arthritis Rheum. 2005;52(12):3928-3933
PubMed   |  Link to Article
Robertsson O, Dunbar MJ, Knutson K, Lidgren L. Past incidence and future demand for knee arthroplasty in Sweden: a report from the Swedish Knee Arthroplasty Register regarding the effect of past and future population changes on the number of arthroplasties performed.  Acta Orthop Scand. 2000;71(4):376-380
PubMed   |  Link to Article
Mehrotra C, Remington PL, Naimi TS, Washington W, Miller R. Trends in total knee replacement surgeries and implications for public health, 1990-2000.  Public Health Rep. 2005;120(3):278-282
PubMed
Khatod M, Inacio M, Paxton EW,  et al.  Knee replacement: epidemiology, outcomes, and trends in Southern California: 17 080 replacements from 1995 through 2004.  Acta Orthop. 2008;79(6):812-819
PubMed   |  Link to Article
Silverman E, Skinner J. Medicare upcoding and hospital ownership.  J Health Econ. 2004;23(2):369-389
PubMed   |  Link to Article
Davis C, Rhodes DJ. The impact of DRGs on the cost and quality of health care in the United States.  Health Policy. 1988;9(2):117-131
PubMed   |  Link to Article
Chulis GS. Assessing Medicare's prospective payment system for hospitals.  Med Care Rev. 1991;48(2):167-206
PubMed   |  Link to Article
Baker DW, Einstadter D, Husak SS, Cebul RD. Trends in postdischarge mortality and readmissions: has length of stay declined too far?  Arch Intern Med. 2004;164(5):538-544
PubMed   |  Link to Article

Letters

CME
Meets CME requirements for:
Browse CME for all U.S. States
Accreditation Information
The American Medical Association is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. The AMA designates this journal-based CME activity for a maximum of 1 AMA PRA Category 1 CreditTM per course. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Physicians who complete the CME course and score at least 80% correct on the quiz are eligible for AMA PRA Category 1 CreditTM.
Note: You must get at least of the answers correct to pass this quiz.
You have not filled in all the answers to complete this quiz
The following questions were not answered:
Sorry, you have unsuccessfully completed this CME quiz with a score of
The following questions were not answered correctly:
Commitment to Change (optional):
Indicate what change(s) you will implement in your practice, if any, based on this CME course.
Your quiz results:
The filled radio buttons indicate your responses. The preferred responses are highlighted
For CME Course: A Proposed Model for Initial Assessment and Management of Acute Heart Failure Syndromes
Indicate what changes(s) you will implement in your practice, if any, based on this CME course.

Multimedia

Data Supplements
Supplemental Content

Some tools below are only available to our subscribers or users with an online account.

Web of Science® Times Cited: 47

Related Content

Customize your page view by dragging & repositioning the boxes below.

Articles Related By Topic
Related Collections
PubMed Articles