Acute and subacute rehabilitation

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DEPARTMENTS

Letters to the Editor Acute and Subacute Rehabilitation We appreciate the contribution of Keith and colleagues ~ in presenting a comparison of costs and outcomes of subacute rehabilitation (SR) and acute rehabilitation. What they denote as "acute rehabilitation" we prefer to call conventional rehabilitation (CR), although we acknowledge that usage varies within physiatry) We agree that more research on outcomes in rehabilitation in general is needed, and that the relative cost-effectiveness of subacute rehabilitation is in need of systematic study. We also agree that SR, originally introduced as a complement to CR, is increasingly used as a substitute for CR. The more this happens, the greater the importance of comparing costs and outcomes of these two rehabilitation modalities. The authors are well aware of the limitations of their retrospective, correlational study, which include: (1) problems in measuring cost and outcomes; (2) the inability to generalize to rehabilitation patients with conditions other than stroke; (3) the absence of an index of severity; and (4) the lack of comparability of the two groups of patients because of nourandom assignment to the two treatment modalities. The nonrandom assignment resulted in significant socioeconomic differences between the patients seen in the two settings. Seventy-four percent of patients in CR were white, compared to 45% in SR. In addition, 25% of the patients in CR had a managed care program as their principal payment source, compared to 59% of the SR patients. Other differences may exist between the two groups of patients that could account for differences in outcome. A key finding of the study was that SR is more cost-effective than CR. However, we want to draw attention to the fact that the CR patients had substantially better functional outcomes (Functional Independence Measure 3 gains) than did the SR patients. If such results were obtained in a randomized clinical trial of efficacy between two alternative treatments, CR would clearly have the advantage over SR. There are technical problems with the use of change scores. 4 We would have preferred to see an analysis in which the discharge FIM score, rather than the change score, was the dependent variable in a regression model that included admission FIM score as one of the dependent variables. The authors report that a chi-square test of differences in discharge destination is statistically significant. We doubt that treating the discharge destinations as four ordered categories (residential setting, nursing home, acute care hospital, other) is the most useful interpretation of the data for the purpose of comparing outcomes. The distinction between nursing home, acute care hospital, and other discharge destination seems comparatively unimportant in the light of rehabilitation's overall goal of returning people to their own homes and to self-care. Table 1: Number and Percentage of Patients Discharged to Home From Conventional and Subacute Rehabilitation

Home Not Home

Conventional

Subacute

235 (71.0%) 96 (29.0%)

65 (67.0%) 32 (33.0%)

Adapted from Keith and colleagues)

Arch Phys Med Rehabil Vol 77, January 1996

Treatment Modality (SR vs CR) Functional Outcome

Treatment Exposure

Fig 1. A path model of the direct effect of treatment modality on functional outcome, controlling for treatment exposure.

It is more instructive to group the discharge destination into two classes, patients who went home, and patients who did not. Table 1, adapted from their table 4, shows the results of the reclassification of discharge destinations. The revised table produces a chi-square value of .5688, with one degree of freedom, and a probability of .4508. We are not convinced that the data show a statistically significant difference in discharge destination between the two groups of patients. The authors attribute much of the difference in functional outcome to large differences in treatment exposure in favor of CR. Had the purpose of the study been to determine whether therapy improves function, such a result would support a conclusion of a positive dose-response relationship between the amount of therapy and the degree of functional gain. The research was, however, "a preliminary investigation of the comparative merits of acute and subacute rehabilitation for stroke" (p 496). Intensity of treatment exposure varies both between and within these two treatment settings. The stepwise regression analysis that they present tests the hypothesis that treatment modality (SR versus CR) has an independent, direct effect on functional gain when controlling on other variables, including treatment exposure. The implied causal model of this analysis is depicted by the path model in figure 1. The other independent

Treatment Modality (SR vs CR)

,1

Functional Outcome

Treatment Exposure

Fig 2. A path model of the direct and indirect effects of treatment modairy on functional outcome, controlling for treatment exposure.

LI:'I-I'ERS TO THE EDITOR

variables in the regression analysis have been omitted for the sake of simplicity.) We suggest an alternative model to test the hypothesis that SR and CR produce different functional gains, a model in which treatment exposure is an intervening variable between facility and functional gain, as shown in figure 2. The latter model allows an examination of both independent direct effects and indirect effects, if any, of rehabilitation modality on functional outcome. A more fully developed model might begin with age and ethnicity as exogenous variables, with payment source, severity index, number of days between onset and admission to rehabilitation, treatment modality, admission FIM score, treatment exposure, and length of stay as intervening endogenous variables, and discharge FIM score as the ultimate dependent variable. Such an analysis compares the two modalities more satisfactorily than a single regression equation by taking into account the possibility of both direct and indirect effects. It also helps to explain why some people do better in rehabilitation than others.

with spinal cord injury (SCI). Consistent with the research methodologic guidelines presented by Bond and associates, we conducted a meta-analytic study and reviewed 100 published articles in SCI psychosocial rehabilitation for methodologic soundness. We found that: (1) only 31% provided a research hypothesis; (2) 62% provided a description of sampling; (3) only 5% used random assignment to experimental conditions; (4) 50% documented reliability of measures used; (5) 90% accurately reported statistics; (6) 81% were complete in reporting statistics; (7) only 7% controlled for type I error; (8) only 1% reported statistical power; (9) only 1% reported effect sizes; (10) 90% chose appropriate statistical tests; and (11) 62% drew appropriate conclusions. Most striking are the low percentages of articles that provide a hypothesis statement (31%), a calculation of power a priori (1%), and reporting of effect size (1%). We fully support the guidelines offered by Bond and associates to underscore the need for quality research in medical rehabilitation, and stringent editorial guidelines. These are essential if rehabilitation research standards are to be elevated.

Richard Salcido, MD Robert W. Moore, PhD Department of PM&R University of Kentucky Lexington, KY 40536

Mary J. McAweeney, PhD Denise G. Tate, PhD William J. McAweeney, MS, CRC University of Michigan Medical Center Ann Arbor, MI 48109

References 1. KeithRA, Wilson DB, Gutierrez P. Acute and subacute rehabilitation for stroke: a comparison. Arch Phys Med Rehabil 1995;76:495-500. 2. Salcido R, Moore RW, Klim GV, Schleenbaker RE: The Physiatrist and subacute rehabilitation. Phys Med Rehabil Clin North Am. In press. 3. Keith RA, Granger CV, Hamilton BB, Sherwin FS. The Functional Independence Measure: a new tool for rehabilitation. In: Eisenberg MG, Grzesiak RC, editors. Advances in clinical rehabilitation. Vol. 1. New York: Springer, 1987:6-18. 4. Johnson MV. Cost-benefitmethodologies in rehabilitation.In: Fuhrer MJ, editor. Rehabilitationoutcomes: analysis and measurement.Baltimore: Paul H. Brookes, 1987:103.

Statistical Guidelines Drs. Bond, Mintz, and McHugo ~ provide a cogent argument for guidelines that emphasize the statistical elements of a study that should be incorporated into the process of reviewing manuscripts for the Archives of Physical Medicine and Rehabilitation. They state that "the imperfections in the research literature are found more frequently in flaws of design and methodology than in the narrow confines of statistical procedures" (p 786). Specifically, Bond and associates convincingly outline the elements necessary for quality research. According to the authors the following 10 aspects are necessary for a study to be adequate: (1) provide a research hypothesis; (2) description of a sampling; (3) assignment to experimental conditions; (4) documentation of measures used; (5) accuracy of reported statistics; (6) completeness in reporting statistics; (7) significance and alpha levels; (8) reporting of statistical power and effect sizes; (9) choice of statistical tests; and (10) drawing appropriate conclusions. Although empirical data were not presented to support conclusions of poor research methods in rehabilitation medicine, it has been our experience that methodologic deficiencies are prevalent in rehabilitation psychology as it pertains to persons

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Reference 1. Bond GR, Mintz J, McHugo GJ. Statistical guidelines for the Archives of PM&R. Arch Phys Med Rehabil 1995;76:784-7.

The authors reply We commend Dr. McAweeney and her colleagues for their review of the spinal cord injury (SCI) literature, documenting statistical and methodological shortcomings. We cataloged a range of deficiencies found in many studies in the behavioral and health sciences, but, as they note, we did not provide concretc data from the rehabilitation literature. Their prompt use of our framework to "document deficiencies is one logical next step in the process of upgrading standards. We hope others will follow their example. One point in their letter needs clarification. They state that we outline "the elements necessary for quality research." Our task was actually more modest--to identify some of the elements necessary for reporting study findings. Although excellence in the conduct of a study is often probably correlated with the quality of reporting it, the two are conceptually distinct. There are additional criteria one would use for assessing the adequacy of the conduct of a study (eg, see Mintz and associates ~). McAweeney and colleagues' application of our framework offers concrete information on where the deficiencies lie in the SCI literature. We strongly suspect that similar deficiencies are found in most other rehabilitation domains, but of course that is an empirical question. It would be valuable to repeat their exercise not only for other research domains, but also for specific journals. For example, it would be useful to document the statistical reporting patterns in the Archives of Physical Medicine and Rehabilitation. Because our statistical guidelines were developed in response to the Editorial Board's interest in enhancing statistical reporting, it would be particularly gratifying to show improvements in papers accepted for publication in the Archives after these guidelines appeared. We would sound a cautionary note, however, in efforts to

Arch Phys Med Rehabil Vol 77, January 1996