Archives of Physical Medicine and Rehabilitation
Volume 90, Issue 8 , Pages 1257-1259, August 2009

Commentary on the Comparative Effectiveness of Alternative Settings for Joint Replacement Rehabilitation

  • Margaret G. Stineman, MD

      Affiliations

    • Department of Rehabilitation Medicine, the Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania School of Medicine, Philadelphia, PA
    • ,
  • Leighton Chan, MD, MPH

      Affiliations

    • Rehabilitation Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD
    • Corresponding Author InformationReprint requests to Leighton Chan, MD, MPH, Chief, Rehabilitation Medicine Department, Clinical Center, National Institutes of Health, Building 10, CRC, Room 1-1469, 10 Center Dr, MSC 1604, Bethesda, MD 20892-1604

Article Outline

Abstract 

Stineman MG, Chan L. Commentary on the comparative effectiveness of alternative settings for joint replacement rehabilitation.

The comprehensive Joint Replacement Outcomes in Inpatient Rehabilitation Facilities and Nursing Treatment Sites 1 and 2 studies presented in this issue of the Archives by DeJong and colleagues focus on an important issue facing U.S. rehabilitation today: the comparative effectiveness of alternative rehabilitation settings for the management of conditions such as joint replacement. Although there are hints in the data that patients receiving care in inpatient rehabilitation facilities compared with those treated in skilled nursing facilities may have slightly better recoveries of physical function, the evidence is weaker than for a number of other conditions. It is important to look beyond the question of which setting is best, toward gaining a deeper understanding of the elements within these settings that most enhance outcomes.

Key Words: Delivery of health care, Hospitalization, Joints, Nursing facilities, skilled, Outcome assessment (health care), Rehabilitation

List of Abbreviations: IRF, inpatient rehabilitation facility, PAC, postacute care, SF-12, Medical Outcomes Study 12-Item Short-Form Health Survey, SNF, skilled nursing facility

 

THE AMERICAN RECOVERY and Reinvestment Act of 2009 recently allocated $1.1 billion for comparative effectiveness research with the goal of identifying effective forms of treatment1 and reducing costs. This activity is critical given that the Medicare trust fund reserves will be exhausted by 2017, and it has particular relevance to rehabilitation because PAC services now consume an ever increasing portion of the fund's expenditures.

One of the central questions facing PAC providers is how to treat patients after orthopedic surgeries. There is significant controversy surrounding the relative benefits of treatment in SNFs, IRFs, home care, and outpatient rehabilitation settings, particularly for conditions such as joint replacements.2 The stakes are quite high. Much of the recent 5% decline in Medicare IRF expenditures can be linked to a reduction in the treatment of these cases.3

In this environment, DeJong and colleagues2, 5, 6, 7, 8 have performed an ambitious research project, the results of which are reported in 5 separate articles in this month's Archives. Using a prospective observational cohort design4 and established collaborations with 11 IRFs and 9 SNFs (including 1 hospital-based SNF), DeJong and colleagues2, 5, 6, 7, 8 followed 2152 consecutive orthopedic cases (65% knee replacements, 35% hip replacements) for 6 to 8 months. These studies have a number of strengths, including a large sample size, a significant number of participating facilities, geographic diversity, and a reflection of real world clinical practice. However, these strengths are accompanied by some weaknesses, including the potential for selection bias by setting, and the fact that only 1 hybrid SNF was included, making these findings difficult to interpret.

The studies do not provide a clear winner in the IRF versus SNF controversy, but rather highlight the need to move beyond the payment site controversy to gain additional information regarding which treatment components of the IRF and SNF black boxes are required for good outcomes.9 In sum, the investigators found minimal differences in outcomes between sites. While those admitted to an IRF for a hip replacement had slightly better long-term functional scores, multivariate regression analysis controlling for baseline patient characteristics revealed that the place of treatment (IRF vs SNF) had less effect on outcome than other variables such as treatment volume, patient age, initial FIM scores, and severity of illness.

The authors report an inverse relationship between length of stay and intensity of therapy presented, suggesting that there may be a quantity of inpatient therapy that can be delivered either more intensely over a shorter period or less intensely but over a longer period.5 Higher-intensity therapy in an IRF or hybrid SNF may not be more costly in the long run if it would take more treatment days at lower levels of intensity in an SNF for a patient to reach the same functional goal. Consequently, it may be misguided to see care in an SNF as a direct substitute for care in an IRF or vice versa. This highlights the importance of distinguishing patients who would benefit from longer, lower-intensity treatments available in an SNF from those who can tolerate short, higher-intensity therapies in an IRF.

The authors' third article6 reports the functional outcomes across IRFs and SNFs. Results concerning the incremental benefits of IRFs over SNFs for the recovery of physical function at discharge are inconclusive. The seemingly meaningful incremental benefit of 4.6 motor FIM points for knee replacement and 7.3 points for hip replacement may be simplistically misleading because it was reported for the comparison between medium-volume IRFs and low-volume SNFs only and does not compare the relative effectiveness of these settings overall. Most strikingly, patient characteristics appear to explain far more of the variance in patients' motor FIM discharge scores than treatment-related variables. For the regression analysis shown in table 5 predicting discharge motor FIM score, admission motor FIM explained 27.5% and 31.1% of the partial R2 in patients with knee and hip replacement, respectively. The IRF versus SNF variable, in contrast, explained less than 1% of the variance in both cases. Treatment intensity had a similarly small but statistically significant effect.

At the population level, the evidence in favor of more intensive over less intensive forms of rehabilitation care for elective joint replacement seems less convincing than for other conditions such as stroke, traumatic brain injury, and lower-extremity amputation.10, 11, 12, 13, 14 The conclusion that IRFs offer little incremental benefit over SNFs for patients with joint replacement at the population level, however, should not be interpreted as suggesting that there are never people who would benefit from one type of setting over the other type. There is a great deal of heterogeneity within the joint replacement population. Consequently, it will be essential to compare settings according to the outcomes achieved by patients with different characteristics.

Consistent across IRFs and SNFs and for both the knee and hip replacement populations, medium-volume rehabilitation programs (those treating between 100 and 183 patients with joint replacement yearly) achieved the highest average discharge motor FIM scores. This could suggest that clinicians need to experience the treatment of a certain number of patients with joint replacement to achieve the specialized knowledge required to optimize their functional recoveries. The influence of volume on the quality of outcomes provided by other medical fields requiring technical skill, particularly surgery, is well established.15, 16 Policies like the 75% rule, which may limit a particular facility's treatment volume of patients with joint replacement, could inadvertently reduce the quality of care provided if facilities are unable to admit the requisite numbers of patients to achieve therapeutic proficiency. The finding that patients who received rehabilitation in high-volume SNFs and IRFs did not fare as well as those treated in medium-volume facilities is harder to interpret. Perhaps at some point, volume becomes too high and the capacity to individualize and coordinate therapy is reduced. Because the numbers of facilities in each volume group are small, care must be taken not to overinterpret these findings.

The authors' fourth article7 addresses follow-up care and the use of additional rehabilitation and health care services after SNF or IRF discharge. While there was great variability in the number of home and outpatient rehabilitation visits across subjects, the number of outpatient and homecare visits for patients with knee replacement was remarkably similar across settings. However, those who go on to a second PAC setting receive about twice as much and those who go on to a third PAC setting about 3 times as much therapy. It is reasonable and expected that people after joint replacement with residual functional limitations of sufficient severity to require an IRF or SNF stay would need to move through a continuum of inpatient and outpatient (or home care) services as they progressively gain functional independence. However, if services are received in 1 setting, it would be reasonable that fewer services might be required in the next setting.

The final article8 in this series addressed motor FIM and SF-12 outcomes on average 7.5 months after admission to an IRF or SNF. IRF patients made the highest motor FIM gains at follow-up, but comparative differences explained by the setting variable in multivariable regressions were modest and further reduced in magnitude after controlling for case mix. Moreover, outcomes did not differ significantly for the SF-12. As was true at the time of discharge, patients' clinical characteristics explained more variation in longer-term follow-up outcomes than did treatment setting. The interpretation of results was complicated by sample heterogeneity and lack of sufficient overlap in the characteristics of patients with joint replacement served in SNFs and IRFs. This made it necessary to exclude the most severe from the analytic comparison. This may have biased the analysis because more severe cases were more common in IRFs than in SNFs. Consequently, a conclusion of little comparative benefit can only be drawn for the subgroup of patients with joint replacement who clinically had less severe conditions.

In conclusion, there are hints in these findings that IRFs may yield slightly better motor FIM gains for people after knee or hip replacement, but the level of evidence is not as strong as for other conditions. There are also suggestions that incremental benefits for IRF level rehabilitation (if any) for functional recovery may relate to certain qualities intrinsic to the IRF setting. These include the provision of higher-intensity therapy over shorter periods and the treatment of higher volumes of persons after joint replacement. In the end, however, the work performed by DeJong and colleagues suggests that the better question is not whether IRFs are superior to SNFs, but rather for which types of patients the particular active ingredients of each setting are more effective and necessary. Moreover, future research must look beyond the first PAC setting to the entire phase of PAC care, and to how PAC care links with acute care. Identifying the active therapeutic ingredients and synergies through the entire care continuum will be important as the PAC system is reconfigured and new policies established.

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References 

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 No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which the authors are associated.

PII: S0003-9993(09)00342-6

doi:10.1016/j.apmr.2009.05.004

Archives of Physical Medicine and Rehabilitation
Volume 90, Issue 8 , Pages 1257-1259, August 2009

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