| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
(Stroke. 2002;33:218.)
© 2002 American Heart Association, Inc.
Original Contributions |
From the Servizio Malattie Cerebrovascolari, USL 2, Perugia, Italy.
Correspondence to Dr Maria Grazia Celani, Servizio Malattie Cerebrovascolari, USL 2, Via Guerra 17, 06127 Perugia, Italy. E-mail istitaly{at}unipg.it
| Abstract |
|---|
|
|
|---|
Methods We used data from 2423 patients interviewed by telephone at 6 months after the event. The
statistic, sensitivity, and specificity were calculated for several comparisons. Internal consistency for BI was calculated.
Results The reliability of the dependency question compared with BI=20 (
=0.93) and the reliability of the recovery question compared with OHS=0 (
=0.89) were good. Sensitivity of the dependency question in predicting whether patients scored BI >18 was 0.98; sensitivity of the recovery question in predicting whether patients scored OHS=0 was 0.99. The reliability of BI=20 compared with OHS <3 was good (
=0.87). Internal consistency of BI was very high (Cronbachs
=0.96).
Conclusions The 2 simple questions are a good means of evaluating outcome from a patients view and of dichotomizing the stroke survivor in a time-effective and reliable way.
Key Words: disability evaluation outcome assessment stroke, acute
| Introduction |
|---|
|
|
|---|
In a review of acute stroke trials from 1955 to 1995,1 24% of the trials failed to report data on deaths, and a significantly higher number of trials considered impairment (76%) rather than disability (42%) or, to an even lesser extent, handicap or quality of life (2%) as a measure of outcome. In the same review, the Barthel Index (BI)2 was the most common measure for disability (21%), and the Rankin3 or modified Rankin Scale, also referred to as the Oxford Handicap Scale (OHS),4 was the most common measure for disability/handicap (9%).
Recently, 2 simple questions have been proposed to dichotomize stroke survivors into those who are dependent or those who are independent and, for those who are independent, into those who have a good or a fair recovery.57 This novel measure has been used with ease in a large number of countries with different cultures and varying medical practices, as seen in 2 large pragmatic stroke trials, the International Stroke Trial (IST)8 and the Chinese Acute Stroke Trial,9 in a smaller trial on low-molecular-weight heparin in acute ischemic stroke,10 and in a replication study with a larger sample.11
The reliability of the BI and OHS by telephone and postal questionnaire compared with the "gold standard" of a clinical visit has been established,5,12,13 and the 2 simple questions have also been validated.5,6
The aim of this study is to assess, by telephone interview in a large number of stroke survivors, the relationship between the new measure and the BI and OHS and subsequently between the BI and the OHS. The internal consistency of the BI will also be evaluated.
| Subjects and Methods |
|---|
|
|
|---|
The IST scheduled a postal or telephone follow-up at 6 months after stroke, in which recovery was assessed by the question, "Do you feel that you have made a complete recovery from your stroke?" (question 1 [Q1]); dependency was assessed by the question, "Do you require help from another person for everyday activities?" (question 2 [Q2]). Information on usual residence and current medications or death and possible cause of death was also collected. Additionally, in the present study, responses for the BI and OHS were elicited.
Since the most common means of communication in Italy is by telephone, 1 physician (T.A.C.) with experience in stroke cases was assigned to personally contact each patient for follow-up. Whenever the patient could not be reached because of cognitive communication problems or because the patient was not at home, the caregiver or closest relative (who is often the same person in Italy) was interviewed. Only if it was impossible to trace the patient was the general practitioner contacted because general practitioners would not have recorded detailed information on their patients disabilities or handicaps.
The telephone calls were performed as follows: the interviewer began with the 2 questions, then a brief conversation followed, in which the information required to complete the items of the 2 scales was elicited. All responses were recorded immediately to avoid any interference from the interviewer. When possible, the conversation was conducted as a friendly long chat to optimize the quality of the answers, to minimize the anxiety that could arise when talking about daily limitations, and to respect the patients privacy. The BI (0 to 20) was used to measure daily activities, where BI=20 indicates "not disabled"; the OHS (0 to 5) was used to determine disability/handicap, where 0 indicates "fully recovered" and <3 "good outcome."
The analysis was performed as follows: The levels of sensitivity, specificity, and accuracy of the dependency question (Q2) and the recovery question (Q1) were compared with the most common BI "good outcome" cutoffs reported in previous studies.6,14 The aforementioned evaluations were also performed to compare Q1 with OHS=0. Then a BI score of 0 was used as gold standard versus OHS=0 and OHS <3.
Unweighted
15 with 95% CI was used to assess agreement without the play of chance between the 2 questions and each of the complex scales and between the 2 scales themselves. The internal consistency of the BI was assessed by Cronbachs
.16,17 The relation between total BI score and individual BI tasks was analyzed by means of the Spearman rank correlation test.
| Results |
|---|
|
|
|---|
Therefore, the results of Q1, Q2, BI, and OHS for a total of 2423 patients were considered in the present study. The mean age was 70.5 years (range, 20 to 99 years). There were 1016 women (42%; mean age, 73.3 years) and 1407 men (58%; mean age, 68.5 years). In 35.7% of cases, patients were contacted personally.
When we compared Q2 with previously reported BI cutoffs, BI >18 produced the best reproducibility (
=0.95, sensitivity=0.98, specificity=0.97, accuracy=0.98). BI=20 (
=0.93, sensitivity=0.99, specificity=0.93, accuracy=0.96) and BI >17 (
=0.94, sensitivity=0.96, specificity=0.99, accuracy=0.98) had similar results, albeit with slightly lower
index. (Table 1).
|
Similarly, Q1 compared with OHS=0 resulted in sensitivity=0.99, specificity=0.96, accuracy=0.96, and
=0.89 (Table 2). To ascertain whether there was any agreement between "fully recovered" and "not disabled," Q1 was compared with the best BI score (20), resulting in a poor agreement (
=0.35) and relatively low accuracy (accuracy=0.66) (Table 3). There were differences in the judgment regarding complete recovery (Q1) and independence (BI=20) between patient and caregiver; in fact, when the patients self-evaluated their own outcome, specificity and agreement between the 2 measures were poor (specificity=0.36,
=0.20), while when the caregivers answered, the measures improved (specificity=0.73,
=0.43) (Table 4).
|
|
|
To better understand the meaning of the 2 different OHS cutoffs, OHS=0 and OHS <3 were compared with the best score of BI (20). The former comparison gave a very low sensitivity (sensitivity=0.36) as well as agreement (
=0.36), while in the latter sensitivity (sensitivity=0.94), specificity (specificity=0.93), and agreement (
=0.87) were very high (Table 5). Similar results were obtained when we compared OHS <3 and the dependency question (sensitivity=0.94, specificity=0.98,
=0.91) (Table 6). This confirms that stroke survivors with an OHS score of <3 are to be considered functionally recovered.
|
|
Internal consistency was evaluated to determine whether there was a single item in the BI able to predict the total score. The correlation index and dissimilarities index were calculated for each ordinal variable. We eliminated the effect of the score of the item on the total score without the contribution of the considered particular item. Cronbachs
showed that the BI had a high internal consistency (
=0.96). All 10 items were strictly correlated with the total score, with a value of R=0.937 for dressing and R=0.929 for climbing stairs (Table 7).
|
| Discussion |
|---|
|
|
|---|
The strong correlation between Q2 and BI >18 and between Q1 and OHS=0 indicates that the 2 questions actually measure what they were intended to, ie, independence and full recovery, in a quick, simple, and direct manner. Q1 mainly identifies patients who regain a good functional, cognitive, and psychological state (436/520 true positive in our series) and also identifies those with health limitations before the stroke (84/520 false-positive [16.2%]; 95% CI, 13 to 19.3). Indeed, the main difference between Q1 and OHS=0 is that the latter indicates those patients with a complete absence of symptoms due to any cause. Furthermore, agreement between Q1 and the maximum BI is poor, reinforcing the well-known concept that independent patients do not consider themselves healthy if they suffer from even minor residual stroke symptoms and perceive that this affects their life.
This becomes more evident when answers from patients are compared with those from caregivers. Agreement between Q1 and absence of disability (BI=20) is very poor in the first case, in which a self-evaluation is made (
=0.20), while it improves to moderate (
=0.43) when the caregiver attempts to evaluate the patients condition. From the patients point of view, this could mean that a feeling of lost previous life exists and that "there is more to life than getting into the bath on ones own."18 However, this consideration must be taken cautiously; in fact, it is highly probable that the caregiver answered more frequently when the outcome was poor, and thus the better agreement may be due to a greater proportion of patients being definitely disabled and not recovered.
When the 2 complex scales are compared, there is a strong correlation between no disability (BI=20) and absence of handicap (OHS <3). This is crucial because the latter has been widely used in many recent clinical trials on both secondary prevention and acute treatment. Our data confirm the suggestion that OHS is basically a disability scale when the cutoff between 2 and 3 is used to separate surviving stroke patients into categories. However, this would exclude those independent patients who have psychological and/or cognitive problems or undergo a change of lifestyle, which in our series amounted only to 70 of 1223 (5.7%; 95% CI, 4.5 to 7). These findings are similar to those reported by de Haan et al,19 in which mobility, disability in daily living, and instrumental activity scales showed a stronger association with OHS than cognitive and social functioning scales.
BI score of 20, OHS score <3, and a negative answer to Q2 all indicate independence. In a multicenter study or in cases of local monitoring involving >1 clinician, the simplest and most easily reproducible measure should be used, which is BI or, optimally, Q2. However, whenever assessment is performed by a single expert, OHS is recommended because, to a certain extent, it affords the distinction between disability and handicap, which in our series was 5.7%.
If cutoff is considered between OHS=0 (ie, no symptoms) and OHS >0, the scale would then become a handicap scale because symptoms, whether related to stroke or not, interfere with social life. Thus, if a disability scale is desired, it would be advisable to use OHS=0 as well.
Furthermore, our results show that each item of the BI measures the same concept; in fact, each predicts the main result equally well. This reflects the homogeneity of the scale and its inter-item consistency and explains its wide international application. However, in Italy, the most indicative item reported by telephone was dressing. In a similar study in Britain, bathing was found to be the most indicative item,5 while in Japan, feeding was less indicative,20 suggesting that when even a simple parameter such as disability is measured, cultural differences must be taken into account. Indeed, the most indicative item should be investigated to the fullest during the interview to better evaluate disability and focus on the most sensitive tasks in rehabilitation.
The findings of the present study support the use of the 2 questions when evaluating the outcome of stroke patients. They are easy to administer (even on the telephone), brief, cost effective, and valid in measuring disability and complete recovery to prestroke status. Any differences between these 2 questions and the more complex measures, ie, BI <20 and OHS=0, are negligible, especially in large stroke series, allowing large, pragmatic stroke trials to be completed. On the other hand, they are not able to describe handicap or quality of life restrictions if they are not directly or indirectly related to the stroke event.
The OHS maintains its function as a handicap scale only if the dichotomy is between 0 and >0. In fact, scores 1 and 2 refer to quality of life (symptoms without impairment or disability) and social roles (lifestyle). The more frequent use of the OHS with a cutoff between 2 and 3 describes the functional status of the patient, as does the BI. A balance should be considered between the ease in administering the BI, including the easiest dependency question, and the comprehensiveness of the OHS, which is able to identify those people suffering from a decline in social well-being, even if they are few in number. In stroke rehabilitation clinics, where a precise estimate of stroke outcome in an individual patient is mandatory, the 2 questions and OHS and BI could be used to obtain a global view of a patients life and to monitor clinical improvement. These scales and the 2 questions could be also used in small analytical treatment studies, in which follow-up could be accomplished at a higher cost and with more time by means of a local visit, bearing in mind that detailed measures can be unreliable if studies include only a few subjects, since the effect of random variation is likely to be larger than the effect of the treatment.5,21 However, the 2 questions may be used alone in large, pragmatic trials because it is far better to use a simpler (but valid) outcome measure in thousands of patients than a more complex (and therefore more expensive and possibly unaffordable) measure in a few hundred patients.
Measurement of health-related outcomes should be a compromise between simplicity and patient perspective, as these 2 questions are. These questions may help to solve the problem of dichotomizing the outcome of stroke survivors in a simple manner from the beginning of the trial and not with post hoc analyses.
| Appendix |
|---|
|
|
|---|
| Acknowledgments |
|---|
| Footnotes |
|---|
Received May 31, 2001; revision received September 18, 2001; accepted September 25, 2001.
| References |
|---|
|
|
|---|
2. Mahoney FJ, Barthel DW. Functional evaluation: the Barthel Index. Md State Med J. 1965; 14: 6165.[Medline] [Order article via Infotrieve]
3. Rankin J. Cerebral vascular accidents in patients over the age of 60, II: prognosis. Scott Med J. 1957; 2: 200215.[Medline] [Order article via Infotrieve]
4. Bamford JL, Sandercock PAG, Warlow CP, Slattery J. Interobserver agreement for the assessment of handicap in stroke patients. Stroke. 1989; 20: 828.[Medline] [Order article via Infotrieve]
5. Lindley R, Waddell F, Livingstone M, Sandercock P, Dennis M, Slattery J, Smith B, Warlow C. Can simple questions assess outcome after stroke? Cerebrovasc Dis. 1994; 4: 314324.[CrossRef]
6. Dennis M, Wellwood I, Warlow C. Are simple questions a valid measure of outcome after stroke? Cerebrovasc Dis. 1997; 7: 2227.
7. Dennis M, Wellwood I, ORourke S, Mac Hale S, Warlow C. How reliable are simple questions in assessing outcome after stroke? Cerebrovasc Dis. 1997; 7: 1921.
8. International Stroke Trial Collaborative Group. The International Stroke Trial (IST): a randomised trial of aspirin, subcutaneous heparin, both or neither among 19435 patients with acute ischaemic stroke. Lancet. 1997; 349: 15691581.[CrossRef][Medline] [Order article via Infotrieve]
9. CAST (Chinese Acute Stroke Trial) Collaborative Group. CAST: randomised placebo controlled trial of early aspirin use in 20,000 patients with acute ischaemic stroke. Lancet. 1997; 349: 16411649.[CrossRef][Medline] [Order article via Infotrieve]
10.
Kay R, Wong KS, Yu YL, Chan YW, Tsoi TH, Ahuja AT, Chan FL, Fong KY, Law CB, Wong A, Woo J. Low-molecular weight heparin for the treatment of acute ischemic stroke. N Engl J Med. 1995; 333: 15881593.
11. Hommel M, for the FISS bis Investigators Group. Fraxiparine in Ischaemic Stroke Study (FISS bis). Cerebrovasc Dis. 1998; 8 (suppl 4): 19.
12. Shinar D, Gross CR, Bronstein KS, Licata-Gehr EE, Eden DT, Cabrera AR, Fishman IG, Roth AA, Barwick JA, Kunitz SC. Reliability of the activities of daily living scale and its use in telephone interview. Arch Phys Med Rehabil. 1987; 68: 723728.[Medline] [Order article via Infotrieve]
13. Candelise L, Pinardi G, Aritzu E, Musicco M. Telephone interview for stroke outcome assessment. Cerebrovasc Dis. 1994; 4: 341343.
14.
Sulter G, Steen C, DeKeyser J. Use of the Barthel Index and modified Rankin Scale in acute stroke trials. Stroke. 1999; 30: 15381541.
15.
Duncan PV, Jorgensen HS, Wade DT. Outcome measures in acute stroke trials: a systematic review and some recommendations to improve practice. Stroke. 2000; 31: 14291438.
16. Fleiss JL. Measuring nominal scale agreement among many raters. Psychol Bull. 1971; 76: 378382.[CrossRef]
17. Cronbach LJ. Coefficient alpha and the internal structure of tests. Psychometrika. 1951; 16: 297334.[CrossRef]
18. Van Gijn J. Measurement of outcome in stroke prevention trials. Cerebrovasc Dis. 1992; 2 (suppl 1): 2334.
19.
de Haan R, Limburg M, Bossuyt P, van der Meulen J, Aaronson N. The clinical meaning of Rankin "handicap" grades after stroke. Stroke. 1995; 26: 20272030.
20. Chino N. Efficacy of Barthel Index in evaluating activities of daily living in Japan, the USA and UK. Stroke. 1990; 21 (suppl II): II-264II-265.
21. Peto R. Monitoring cancer patients in clinical trials need not be precise.In: Symington T, Williams AE, Mc Vie JG, eds. Cancer: Assessment and Monitoring: Tenth Pfizer International Symposium. Edinburgh, Scotland: Churchill Livingstone; 1980: 377381.
This article has been cited by other articles:
![]() |
R. Dalemans, L. P de Witte, J. Lemmens, W. J. van den Heuvel, and D. T Wade Measures for rating social participation in people with aphasia: a systematic review Clinical Rehabilitation, June 1, 2008; 22(6): 542 - 555. [Abstract] [PDF] |
||||
![]() |
J. Y. Chong, H. S. Lee, B. Boden-Albala, M. C. Paik, and R. L. Sacco Gender differences in self-report of recovery after stroke: The Northern Manhattan Study. Neurology, October 10, 2006; 67(7): 1282 - 1284. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Uyttenboogaart, R. E. Stewart, P. C.A.J. Vroomen, J. De Keyser, and G.-J. Luijckx Optimizing Cutoff Scores for the Barthel Index and the Modified Rankin Scale for Defining Outcome in Acute Stroke Trials Stroke, September 1, 2005; 36(9): 1984 - 1987. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. E. Thwaites, N. D. Bang, N. H. Dung, H. T. Quy, D. T. T. Oanh, N. T. C. Thoa, N. Q. Hien, N. T. Thuc, N. N. Hai, N. T. N. Lan, et al. Dexamethasone for the Treatment of Tuberculous Meningitis in Adolescents and Adults N. Engl. J. Med., October 21, 2004; 351(17): 1741 - 1751. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Stroke Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2002 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |