P redictors of outcome of rehabilitation of elderly s t roke patients in a geriatric ward

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1 Clinical Rehabilitation 1999; 13: P redictors of outcome of rehabilitation of elderly s t roke patients in a geriatric ward Bente Thommessen, Erik Bautz-Holter and Knut Laake Geriatric Department, Ullevaal Hospital, Oslo, Norway Received 27th March 1998; returned for revisions 30th April 1998; revised manuscript accepted 2nd July Purpose : To identify predictors of outcome after 12 months in elderly stroke patients rehabilitated in a geriatric ward. Design : Prospective with evaluation in the subacute phase and after 12 months. Setting : Geriatric ward and outpatient clinic. Subjects : All stroke patients admitted from the acute unit to a geriatric ward for rehabilitation during a 16-month period (n = 171). Main outcome measures : Place of living, mortality and social functioning (Frenchay Activities Index) 12 months following stroke. Results : Age, urinary incontinence and cognitive function were significantly associated with place of living (home versus nursing home) 12 months post stroke in bivariate analyses. However, using multivariate logistic regression analyses, only age (p = 0.005) and urinary incontinence at baseline (p = 0.028) remained independent predictors of place of living. Mortality during the first year was significantly predicted by urinary incontinence and gender (men doing worse), whereas the Barthel Activities of Daily Living (ADL) Index sumscore was the only significant independent predictor of social activities. Conclusion : Urinary incontinence at baseline seems to be a most important predictor of outcome 12 months post stroke in geriatric patients. However, with regard to social activities (Frenchay Activities Index), functional impairment in the initial phase as reflected by the Barthel ADL Index supersedes other predictors. Introduction Stroke is one of the commonest causes of death and disability in the Western world. This is an age-related disorder with nearly 70% of the subjects being more than 70 years of age. 1 N o r w a y has a total population of four million people, and approximately people per annum suffer a Address for correspondence: Bente Thommessen, Geriatric Department, Ullevaal Hospital, 0407 Oslo, Norway. bente.thommessen@ioks.uio.no stroke. The mortality is 15 20% in the acute stage, and the mean survival period five years. 1 The many studies on predictors of outcome after stroke identify various factors. However, these studies have been undertaken on widely differing populations and come to different conc l u s i o n s. 2 6 Only few of the studies 7 focus on older patients and longer term prognosis. The purpose of the present study was to identify predictors of the outcome after one year of stroke patients admitted to a geriatric rehabilitation ward. Arnold (99)CR228OA

2 1 2 4 B Thommessen et al. Materials and methods One hundred and seventy-one stroke patients admitted to a geriatric ward for rehabilitation at Ullevaal Hospital, Oslo, Norway, between January 1994 and May 1995 were assessed prospectively. Stroke was defined according to the World Health Organization (WHO) defin i t i o n. 8 T h e diagnosis was based upon the patient s history, clinical examination and cerebral computerized tomography (CT) scanning. The patients were those the clinicians assessed as in need of geriatric rehabilitation after a short stay (mean length of stay = 9 days) in the acute ward. Subjects who were under 60 years of age, unconscious, had subarachnoid haemorrhage or were in a terminal state were excluded. The patients were assessed on admittance to the ward (mean 10 days from stroke onset), at discharge, and 12 months post stroke. Place of living at 12 months was used as the principal outcome variable. Social activities among the patients living at home, as reflected by the Frenchay Activities Index, and survival at 12 months were used as secondary outcome variables. A s s e s s m e n t s The activities of daily living (ADL) were assessed by means of the Barthel ADL Index, which contains 10 items with a maximum sumscore of The Sødring Motor Evaluation of Stroke Patients (SMES) was used to measure motor function and activities. 1 0 This test has three subscales: arm (sumscore range 16 80), leg (range 4 20), and gross motor (balance and gait) function (range 12 60). Higher scores are associated with better functioning. Cognitive function was evaluated by means of the Mini-Mental Status Examination (MMSE) which has 20 items. 1 1 A sumscore below indicates cognitive impairment. The Frenchay Activities Index (FAI) scores functioning at a somewhat higher functional level, e.g. housekeeping, recreation, hobbies and social activities. It is believed to measure disability and perhaps to some extent also handicap. 1 2 The sumscore range is 15 60; a higher score r e flects higher activity. Urinary continence was assessed clinically and by the corresponding item in the Barthel ADL Index (continent = 2, occasional accident = 1, i n c o n t i n e n c e = 0 ). S t a t i s t i c s Statistical analysis was performed with the BMDP package using table analysis and logistic and linear regression. 1 3 Results The mean age of the patients was 78.4 y e a r s ( m e d i a n ± SD 80 ± 8.3; interquartile range years), and 102 (59%) were women. The mean length of stay in the acute ward before admittance to the rehabilitation unit was 8.7 d a y s (median ± SD 8.8 ± 7.5; interquartile range 4 11). Mean length of stay in the geriatric ward was 44 days (34 d a y s ± 33; interquartile range ). Four died in hospital, whereas 139 were discharged to home and 28 to a nursing home. One year post stroke, a further 28 had died, 15 more had been admitted to nursing home, and 104 patients were still living at home. At baseline, mean Barthel ADL sumscore was 12.5 median ± SD 13 ± 5.3; interquartile range 8 17) and mean MMSE sumscore 24.5 (median ± SD 26 ± 5.3; interquartile range ). Regarding bladder function, 87 patients (51%) were continent, 59 (34%) had occasional accidents, and 25 (15%) were incontinent. Predictors of place of living at 12 months were i d e n t i fied using bivariate and multivariate logistic regression analyses. For analytical purposes, age and sumscores on the MMSE and Barthel ADL Index were grouped according to tertiles, and arm, leg and gross motor function sumscores dichotomized at the median. The results are presented as the odds ratio (OR) with 95% confidence interval (CI). The odds ratio is statistically s i g n i ficant at p <0.05 if the 95% CI does not encompass the value 1.0. In bivariate analyses, higher age, the presence of urinary incontinence, and poorer cognitive function were statistically associated with higher probability of living in an institution at 12 months (Table 1). However, when these variables were subjected to multivariate logistic regression analysis, only age and urinary incontinence in the acute stage proved to be significant independent

3 Outcome of rehabilitation of elderly stroke patients predictors of place of living (Table 1). Similarly, urinary incontinence (the incontinent ones doing worse) in the acute stage, together with gender (men doing worse), were the only independent predictors of mortality at 12 months post stroke (Table 2). The search for predictors of social functioning at one year was restricted to patients still living Table 1 a n a l y s i s Prediction of place of living (home = 1, nursing home = 0) 12 months post stroke by logistic regression Bivariate analyses Multivariate analysis a Explanatory variables O R 95% CI Adjusted OR 95% CI p- v a l u e Age in years (grouped 74 = 0 (ref.), = 1, 80 = 2 ) b Gender (male = 0 (ref.), female = 1 ) Urinary incontinence (no = 0 (ref.), yes = 1 ) MMSE sumscore (grouped 19 = 2, = 1, 28 = 0 (ref.)) b Barthel ADL index sumscore (grouped 9 = 2, = 1, 16 = 0 (ref.)) b Motor function Arm function (good = 0 (ref.), poor = 1 ) Leg function (good = 0 (ref.), poor = 1 ) Gross motor function (good = 0 (ref.), poor = 1 ) Urinary incontinence (always and occasional = 1, never = 0 ). OR, odds ratio; CI, confidence interval; ref., reference level. a Model fit: goodness of fit chi-square = 15.9, DF = 13, p = b For trichotomized items linearity in the log odds across strata was established and a mean OR was estimated by later specifying the variable as interval-scaled. Table 2 First-year mortality relative to baseline characteristics (logistic regression analyses) Bivariate analyses Multivariate analysis a Explanatory variables O R 95% CI Adjusted OR 95% CI Age in years (grouped 74 = 0 (ref.), = 1, 80 = 2 ) b Gender (male = 0 (ref.), female = 1 ) c Urinary incontinence (no = 0 (ref.), yes = 1 ) MMSE sumscore (grouped 19 = 2, = 1, 28 = 0 (ref.) Barthel Index sumscore (grouped 9 = 2, = 1, 16 = 0 (ref.) Arm function (good = 0 (ref.), poor = 1 ) Leg function (good = 0 (ref.), poor = 1 ) Gross motor function (good = 0 (ref.), poor = 1 ) a Model fit: goodness of fit chi-square = 64, 12 DF = 81, p = b For trichotomized items linearity in the log odds across strata was established and a mean OR was estimated by later specifying the variable as interval-scaled. c Men doing worse.

4 1 2 6 B Thommessen et al. at home. The FAI sumscore conformed well to the normal distribution and so it was appropriate to apply one-way analysis of variance (ANOVA) and linear regression. ANOVA demonstrated statistically significant associations between the FAI sumscore and urinary incontinence, the MMSE sumscore, the Barthel ADL Index sumscore, and arm, leg and gross motor functioning (Table 3). These statistical significant variables were then subjected to multiple linear regression analysis. Only the Barthel sumscore demonstrated a statistically significant and positive relationship with the FAI sumscore one year post stroke (Table 3), whereas cognitive function assessed with the MMSE showed a positive trend (p = 0.06). The Barthel sumscore alone explained 27% of the variance in social activity (FAI), while a model with the Barthel sumscore and MMSE sumscore in all explained 32% of the variance. The model fitted the data well according to plots of the r e s i d u a l s. Discussion In this study of stroke patients rehabilitated in a geriatric ward, being able to live at home 12 months after the stroke was predicted by lower age and urinary continence, and the latter together with gender were the only predictors of survival. We selected the study population of stroke patients so that it was comprised of elderly people with moderate disabilities. Furthermore, the sample size was somewhat limited. Nevertheless, the poorer prognosis of stroke patients with early urinary incontinence observed by us accords with previous studies Wade and coworkers demonstrated that urinary incontinence at baseline, together with age, are the most Table 3 Baseline correlates of social activities (FAI sumscore) at 12 months post stroke Analysis of variance a Multiple linear regression Group mean 95% CI p- v a l u e C o e f fic i e n t p- v a l u e A g e G e n d e r M a l e F e m a l e Urinary incontinence Incontinence: yes < n s Incontinence: no MMSE sumscore Barthel sumscore < < Arm function < n s > Leg function n s > Gross motor function < n s > a One-way ANOVA.

5 Outcome of rehabilitation of elderly stroke patients important adverse prognostic factors both for survival and recovery of function 13 weeks post s t r o k e. 1 9 In a larger, population-based study of functional outcome in patients younger than 75 years of age, Taub e t a l. 1 4 demonstrated that initial urinary incontinence was the best single predictor of disability. Our study demonstrates that these conclusions are also valid for elderly patients one year post stroke. Why there is such a strong relationship between urinary incontinence and an unfavourable outcome after a stroke is still not fully understood. Many studies indicate a correlation between urinary incontinence and the severity of the stroke. It has also been suggested that the location of the lesion and whether it involves a disruption of the neuromicturition pathways may be of importance. 2 0, 2 1 Further studies are still needed to explore this association in more detail. We used the Frenchay Activities Index as an outcome reflecting disability and certain aspects of handicap. Such outcomes are of great importance in stroke rehabilitation and stroke research, and the FAI is an instrument that has been proposed as a standard measure to complement the Barthel ADL Index. 2 2 In bivariate analyses, the FAI sumscore was found to be associated with baseline scores regarding urinary continence, the arm, leg and gross motor function, the Barthel Index, and the MMSE sumscore. The predictive power of the subscales of the Sødring Motor Evaluation of Stroke Patients for social activities has been documented earlier. 2 3 However, when all these variables were subjected to multiple linear regression analyses, only the Barthel ADL Index remained a significant independent predictor. This instrument covers urinary continence, cognition and motor function, and has been demonstrated to be unidimensional in stroke p a t i e n t s. 2 4, 2 5 This means that the Barthel Index would supersede other function measures, a fin d- ing which was actually observed in the multiple regression model. The results of this analysis also show that in this study population of elderly stroke patients, functional impairments in the initial phase of stroke are more important than age and gender for later social functioning (Table 3). References 1 Treatment of stroke patients. Consensus conference January Norges Forskningsråd, Oslo, Ween JE, Alexander MP, D Esposito M, Roberts M. Factors predictive of stroke outcome in a rehabilitation setting. N e u r o l o g y 1996; 4 7: Thorngren M, Westling B. Rehabilitation and achieved health quality after stroke. A populationbased study of 258 hospitalized cases followed for one year. Acta Neurol Scand 1990; 8 2: Galski T, Bruno RL, Zorowitz R, Walker J. Predicting length of stay, functional outcome, and aftercare in the rehabilitation of stroke patients. The dominant role of higher-order cognition. S t r o k e 1993; 2 4: Nakayama H, Jørgensen HS, Raaschou HO, Olsen TS. The influence of age on stroke outcome. The Copenhagen Stroke Study. S t r o k e 1994; 2 5: Wade DT, Langton Hewer RL. Functional abilities after stroke: measurement of natural history and prognosis. J Neurol Neurosurg Psychiatry 1987; 5 0: Kalra L, Crome P. The role of prognostic scores in targeting stroke rehabilitation in elderly patients. J Am Geriatr Soc 1993; 4 1: Hatano S. Experience from a multicentre stroke register: a preliminary report. Bull World Health O r g a n 1976; 5 4: Mahoney F, Barthel D. Functional evaluation: The Barthel index. Md Med J 1965; 1 4: Sødring KM, Bautz-Holter E, Ljunggren AE, Wyller TB. Description and validation of a test of motor function and activities. Scand J Rehabil Med ; 2 7: Folstein M, Folstein S, McHugh P. Mini-Mental State. A practical method for grading cognitive state of patients for the clinician. J Psychiatr Res 1975; 1 2: Holbrook M, Skilbeck C. An activities index for use with stroke patients. Age Ageing 1983; 1 2: Dixon WJ. BMDP statistical software. Berkeley, CA: University of California Press, Taub NA, Wolfe CDA, Richardson E, Burney RGN. Predicting the disability of first-time stroke sufferers at 1 year. S t r o k e 1994; 2 5: Ween JE, Alexander MP, D Esposito, Roberts M. Incontinence after stroke in a rehabilitation setting: outcome associations and predictive factors. N e u r o l o g y 1996; 4 2: Anderson CS, Jamrozik KD, Broadhurst RJ, Stewart-Wynne EG. Predicting survival for 1 y e a r among different subtypes of stroke. Results from the Perth Community Stroke Study. S t r o k e 1994; 2 5: Henriksen T. Urinary incontinence after apoplexy. Ugeskr Laeger 1993; 1 5 5:

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