To the Editor:
Evaluations of the most cost-effective ways of providing rehabilitation after stroke are central to planning stroke care. Although reporting of good-strength, randomized controled trial evidence is necessary in the era of evidence-based medicine, basic principles have to be adhered to. Both the trials by Holmqvist and colleagues1 and Rogers2 are useful pilot studies but are statistically weak and do not provide conclusive evidence for clinicians and health care planners on how to provide care.
In the Swedish trial1 the results are applicable to less than 10% of stroke patients. The main outcome measure for the trial is not specified, and the sample size for detecting a specific difference for this main measure is not detailed. The authors state that 130 patients would be required to detect an unspecified difference in costs; however, the trial includes only 81 patients. Hence, like the evaluation by Rodgers,2 the results must be considered as pilotd data. There is not sufficient power to detect important clinical differences in outcome, and the authors do not discuss the fact that the nonsignificant differences could, with an adequate sample size, become negative outcomes in a larger study.
In a similar trial of early discharge from hospital to a community rehabilitation team in London, UK, we randomized stroke patients in hospital and followed them up for 1 year. There were no significant clinical differences between the groups at 1 year, but the early discharge from hospital to a rehabilitation team option has been shown to be effective.3 This trial required 260 patients to have sufficient power to detect clinically significant differences in Barthel score at 1 year.
If trials are to undertaken, we as clinical researchers have an obligation to ensure that hypotheses can be answered, and this requires rigorous trial design, with adequate numbers of patients to detect differences in outcome should they exist.
- Copyright © 1998 by American Heart Association
Holmqvist LW, von Koch L, Kostulas V, Holm M, Widsell G, Tegler H, Johansson K, Almazán J, de Pedro-Cuesta J. A randomized controlled trial of rehabilitation at home after stroke in southwest Stockholm. Stroke. 1998;29:591–597.
Rodgers H, Soutter J, Kaiser W, Pearson P, Dobson R, Skilbeck C, Bond J. Early supported hospital discharge following acute stroke: pilot study results. Clin Rehabil.. 1997;11:280–287.
Rudd AG, Wolfe CDA, Tilling K, Beech R. The effectiveness of a package of community care on one year outcome of stroke patients. BMJ. 1997;315:1039–1044.
The excellent publication of Rudd and colleaguesR1 published simultaneously with oursR2 and that of Rodgers et alR3 add to the growing recognition that early supported discharge with continuity of rehabilitation at home can be feasible in combination with a considerable reduction in the use of bed-days for stroke patients.
We read with interest the comments by Rudd and colleagues and agree on the importance of rigorous trial design with adequate sample size in trials of community rehabilitation. We did not state in our article, as was mentioned in the letter of Rudd and colleagues, that 130 patients would be required to detect differences in costs. The fact that our trial had a twin purpose, namely, to determine whether our model of home rehabilitation was (1) more effective and/or (2) resource efficient, rendered calculation of study size complex. A detailed description of power calculations in our trial has been published elsewhere.R4 Any potential differences in savings averaging under 7000 Swedish Krona (SKr) per patient were considered irrelevant if differences in effect or patient satisfaction with care were minimal. On the other hand, differences in outcome of less than 40% (closely equivalent to an odds ratio of 1.5) may be questioned because of limitation in sensitivity, reliability of instruments, and in general, validity. As seen from the differences in study size calculated on the basis of different assumptions listed in the Table⇑, the power requirements for demonstrating differences in cost were considerably lower than those for showing statistically significant differences in effect. We concluded that a study size of 130 patients would allow for indication of possible moderate positive effects and demonstrate important differences in secondary effects (odds ratio, >3), as well as savings of a magnitude that could motivate changes in healthcare policy, and thus yield an acceptable balance of results. We acknowledge that our trial included only 81 patients and hence has the power to detect differences in cost for utilization of healthcare resources and not clinical outcome. In this regard, we did not exclude the possibility of pooling our results with those from other planned or ongoing studies in comparable European populations, and we therefore welcome meta-analysis.
As mentioned by Rudd and colleagues, we do not specify one main outcome measure. To our knowledge, there is no consensus on appropriate main outcome measure for studies that focus on moderately disabled stroke patients. As in the study by Rodgers et al,R3 we used several main outcome measures to capture possible effects on impairment, disability, and/or handicap level. Several authorsR5 R6 have recently pointed out that the assessment of stroke disability should take into account not only the patients’ ability to perform basic or instrumental ADL (eg, the Barthel ADL index) but also the patients’ perceptions of their emotional, social, and physical functions and the ease with which they are performed. The battery of stroke disability measurements chosen for our trial fulfills such requirements and has subsequently been recommended by authorities in the field.R5 R6
In a rigorous trial design of community rehabilitation, it is important, in our opinion, to reduce the discrepancies in initial medical attention, care, and rehabilitation. A stroke unit is thus far the only known organization producing services for which an impact on mortality, long-term care, and the level of dependence in ADL has been demonstrated.R7 Unlike those in other studies,R1 R3 all of our patients received similar initial medical attention and early rehabilitation at the Department of Neurology at Huddinge University Hospital, organized as a stroke unit.R2 Thus, when the admittance procedures for stroke patients were altered at the Huddinge Hospital and not all patients from the catchment area received care at the Department of Neurology, we were no longer able to recruit all stroke patients from the population (as was previously the case) nor were we able to ensure similar initial medical attention, care, and rehabilitation. A nursing strike, a physical therapy strike, and periods of shortage of speech therapists were other factors beyond our control that reduced the number of patients included in the study.
Rudd and colleagues point out that our resultsR2 are applicable to less than 10% of the stroke population. In our opinion, it is not likely that there will be one best way of organizing the rehabilitation service that will be feasible for such a heterogenous group as stroke patients. Our studyR2 focused on moderately disabled stroke patients who, in line with prior experience, are those who might benefit most from specific interventions.R8 R9 Our patient selection criteria, based on level of cognitive function and ADL capacity at 1 week, would strengthen the appropriateness of our stroke populationR10 for the purposes of experimental evaluation research into rehabilitation techniques. Nevertheless, the results of our studyR2 should not be used for planning stroke services for the more severe or unspecified type of stroke patients.R10
Rudd AG, Wolfe CDA, Tilling K, Beech R. Randomized controlled trial to evaluate early discharge scheme for patients with stroke. BMI. 1997;315:1039–1044.
Widén Holmqvist L, von Koch L, Kostulas V, Holm M, Widsell G, Tegler H, Johansson K, Almazán J, de Pedro-Cuesta J. A randomized controlled trial of rehabilitation at home after stroke in Southwest Stockholm. Stroke. 1998;98:591–597.
Rodgers H, Soutter J, Kaiser W, Pearson P, Dobson R, Skilbeck C, Bond J. Early supported hospital discharge following acute stroke: pilot study result. Clin Rehabil. 1997;11:280–287.
Widén Holmqvist L. Development and Evaluation of Rehabilitation at Home After Stroke in South-west Stockholm [thesis]. Stockholm, Sweden: Karolinska Institute; 1997.
Duncan PW. Stroke disability. Phys Ther. 1994;74:399–407.
Wade DT. Measurement of Neurological Rehabilitation. Oxford, UK: Oxford Medical Publications; 1992.
Stroke Unit Trialists’ Collaboration. Collaborative systematic review of randomised trials of organised inpatient (stroke unit) care after stroke. BMJ. 1997;314:1151–1159.
Sunderland A, Fletcher D, Bradley L, Tinson D, Langton Hewer R, Wade DT. Enhanced physical therapy for arm function after stroke: a one year follow up study. J Neurol Neurosurg Psychiatry.. 1994;57:856–858.