INTRODUCTION

Stroke remains one of the major chronic illnesses world-wide that health-care organizations will need to address for the next several decades. This is because it can affect virtually all human functions and unlike other disabling conditions, the onset of stroke is sudden, leaving the individual and the family ill-prepared to deal with its sequelae¹. Stroke is often a catastrophic event affecting all aspects of an individual’s life. The impact of stroke on a patient is usually unanticipated and often devastating, requiring major adjustment in lifestyle and psychology of stroke survivors². Current stroke outcome assessments are often limited to the resulting neurological impairment and functional disability, neglecting to evaluate the total influence of the event on a patient’s well-being³.

                Consensus about the definition of quality of life (QOL) has yet to be reached, but most researchers believe it is multidimensional, comprising here broad "domains"; physical, mental, and social. Quality of life has been defined by the World Health Organization Quality of Life (WHOQOL) Group as "individuals’ perceptions of their position in life in the context of the

culture and value systems in which they live and in relation to their goals, expectations, standards and concern⁴. Health related QOL (HRQOL) is a self-reported measure consisting of multiple dimensions that includes; but is not limited to; physical, social, and emotional health³.

                The Stroke Impact Scale (SIS) has been developed to be a more comprehensive measure of health outcomes for stroke populations⁵. The SIS incorporates meaningful dimensions of function and health-related quality of life into 1 self-report questionnaire. The SIS Version 2.0 includes 64 items and assesses 8 domains [strength, hand function, activities and independent activities of daily living (ADL/IADL), mobility, communication, emotion, memory and thinking, and participation/role function]. Duncan et al^.5 have shown the SIS to be valid, reliable, and sensitive to changes compared with other commonly used measures such as the BI and short form-36 in stroke population.

                There is general agreement that the effects of treatment should be measured in terms of quality as well as quantity of survival. Medical advances may prolong life, but it is important to know the nature of that further life. Without an assessment of QOL, a treatment may be deemed successful despite poor psychosocial functioning or adjustment to illness. Alternatively, a treatment beneficial to psychosocial status may be rejected because it fails to improve physical functioning. The recent development of thrombolytic and neuroprotective therapies has highlighted the urgent need for improved outcome measures for stroke, including QOL measures⁶.

                The aim of the current study was to assess HRQOL of a population-based group of patients with cerebral stroke after one month and again 3 months and to estimate the impact of individual characteristics; such as; age and gender; and clinical correlates; such as; functional level; stroke type and severity; on HRQOL in stroke patients. Lastly we try to evaluate the validity and reliability of the SIS instrument for assessing HRQOL in stroke patients.

SUBJECTS AND METHODS

For the purpose of the present study, 50 surviving patients who had a first-ever-in-a-lifetime stroke between July, 2005 to April, 2007, in Stroke Unit, Neurology Department, Zagazig University Hospital, were eligible for inclusion. Stroke was diagnosed according to the World Health Organization definition⁷. Pathological stroke subtypes (ischemic stroke or intracerebral hemorrhage) was determined using neuroimaging findings. They were 31 (62%) males and 19 (38%) females, their ages ranged from 35 years to 71 years with a mean age of 55.3±8.2 years. Patients were included if they were independent in daily living activities before the stroke. Patients were excluded if they met any of the following criteria: (1) prior stroke with persistent deficit, (2) subarachnoid hemorrhage, (3) dysphasia at one month after stroke such that meaningful communication could not be established, and (4) significant comorbidities likely to concurrently affect HRQOL (such as class III or IV heart failure, peritoneal dialysis or hemodialysis, pre-existing musculoskeletal disease significantly affecting physical function, active psychiatric disease or dementia). We also excluded patients who died during the follow up period.

                The patients were subjected to thorough history taking with special stress on demographic data that included age, sex, smoking, occupations and risk factors. Social participation was assessed using an 8-items question, with 8 being the best possible score (1 point each given for: attendance at study circle, club/association, cinema, religious activity, family gathering, private party, writing letters/e-mail, or any other activity)⁸. Comorbidities were measured by summing the major health problems (e.g. diabetes, cardiovascular disease) reported by stroke survivors and the total score was determined³.

Clinical neurological examination was performed to all patients and impairment was measured with the National Institute of Health Stroke Scale (NIHSS); range 0 to 42⁹. The severity of stroke was classified according to Duncan et al.¹⁰ into mild (NIHSS score is less than 5), moderate (NIHSS score is between 6 and 13) and severe with NIHSS score more than 13. Patients’ functional status was assessed with Barthel Index (BI) and severity of disability was determined by stratifying patients into 3 grades; mild (BI score 15-20), moderate (BI score 8-14), and severe (BI score 0-8)¹¹.

We also evaluated cognitive function by using mini mental state examination (MMSE), (^range 0-30; the best cognitive performance indicated by 30) and we used a cut off score of 24 or less for cognitive impairment (21 for illiterate patients)¹².                      

Depressive symptomatology was assessed by Beck’s depression inventory (BDI)¹³, which is a widely used 21 item depression inventory with answer options from 0-3 and a maximum score of 63. The cut off score for moderate to severe depression used was 17 (18 or more indicates moderate to severe depression)¹⁴.

Routine laboratory investigations including complete blood picture, fasting and postprandial blood sugar, lipid profile, ESR, liver and kidney functions, antinuclear antibodies, were performed to all patients. All patients were undertaken CT examination of the brain to differentiate cerebral ischemia from hemorrhage.

The Stroke Impact Scale (SIS) Version 2.0, that is a 64-items self-report assessment of stroke outcome was used to assess HRQOL in 8 domains: (1) strength, (2) hand function, (3) mobility, (4) physical (ADL) and instrumental (IADL) activities of daily living, (5) memory and thinking, (6) communication, (7) emotion, and (8) social participation. Four of the scales (strength, hand function, ADL/instrumental ADL, mobility) can be combined into an overall physical component score⁵. SIS also includes a question to assess the patients’ global perception of percentage of recovery. After SIS is administrated, the respondent is asked to rate their percent recovery since their stroke on a visual analog scale of 0 to 100, with 0 meaning no recovery and 100 meaning full recovery. 

Statistical Analysis:

                The data were entered, verified, and analyzed using SPSS statistical package for social science version 11. ANOVA test, t-test, and paired t test were used when appropriate and level of significance was considered at P<0.05.  Reliability of the SIS was tested by investigating the consistency of results with Cronbach's α coefficient. As recommended by Nunnally¹⁵, internal estimates of a magnitude of 0.70 or greater were considered reasonable, over 0.80 as good, and over 0.90 as excellent. The validity of the SIS was measured firstly by determining whether it was able to discriminate between subgroups of patients differing in clinical state (discriminated validity) and secondly, by examining its correlation (convergent validity) with the clinical data by using the Pearson correlation coefficient.

RESULTS

The present study was conducted on 50 stroke patients, 31 (62%) males and 19 (38%) females and their ages ranged from 35 years to 71 years with a mean age of 55.3±8.2 years. Twenty one (42%) patients had right hemispheric lesions, whereas 29 (58%) had affected left hemisphere. Cerebral ischemic stroke was detected in 36 (72%) patients, and cerebral hemorrhage in 14 (36%) patients. The most common co-morbidity were; osteoarthosis (46%), diabetes mellitus (36%), cardiac diseases (22%), hepatic diseases (18%), and renal diseases (10%) (Table 1).

Table (2) shows mean (X), standard deviation (SD), 95% confidence intervals (CI) for the eight sub-scales of the SIS instrument together with internal consistency reliability coefficients. The internal reliability assessed using Cronbach`s α statistic was between 0.71 and 0.89 with all exceeding the 0.70 standard except for participation (0.68).

Regarding the changes occurred between first and third months, stroke patients were changing significantly in all dimensions except memory, emotion and communication (Table 3).

Two approaches were taken to evaluate the validity of the SIS instrument: discriminate validity and convergent validity. Table (4) describes mean of the SIS total score compared between groups of patients classified according to some clinical features that significantly impair quality of life (discriminate validity). The mean total score of the SIS was lower (indicating poorer quality of life) in groups with severe disability measured by BI, severe impairment measured by NIHSS, and moderate-severe depression.

Table (5) describes the correlation of sub-scores of the SIS scores with the clinical scales (convergent validity). The physical dimension correlated significantly with age, co-morbidity and NIHSS. Memory domain correlated significantly with co-morbidities and NIHSS, whereas social participation correlated significantly with age, co-morbidities and social score. Emotional domain and communication domains were correlated significantly with social score and MMSE score respectively.

Table 1. Demographic and clinical data among patients with stroke.

SD standard deviation

*Data are expressed  as mean±standard deviation  ** Data are expressed  as range

Table 2. Mean values, confidence intervals for the SIS domains with the Cronbach`s α internal consistency reliability coefficients.

CI confidence interval, SD standard deviation, SIS stroke impact scale

Table 3. Stroke impact scale scores at onset and after 6 months follow up in stroke patients.

ADL activity of daily living, IADL instrumental activity of daily living, SD standard deviation

*Statistically significant at p<0.05 ** Statistically significant at p<0.01

Table 4. Stroke impact scale score compared among groups of stroke patients classified according to some characteristic clinical features or complications that significantly impair QOL.

BI Barthel index, BDI Beck’s depression inventory, NIHSS national institute of health stroke scale, SD standard deviation

*Statistically significant at p<0.05 ** Statistically significant at p<0.01

Table 5. Pearson correlation coefficients of Stroke impact scale score measures with clinical scale in stroke patients.

*Statistically significant at p<0.05 ** Statistically significant at p<0.01

DISSCUSION

The heterogeneity of stroke severity and symptoms has created many challenges to the assessment of stroke outcomes. Stroke impacts not only physical function but also emotion, memory and thinking, communication and role function (social participation)⁵. In this study, we used SIS Version 2.0 to assess HRQOL in 50 patients with stroke at one and three months after discharge. We found that internal consistency (reliability) of the SIS was well above accepted levels (0.70) (range from 0.71 to 0.89) except participation (0.68). This is in agreement to some extent with Duncan et al.⁵, who found that Cronbach’s α coefficients of the SIS ranged from 0.7 to 0.92 of the 8 domains except for emotion (0.57).

The validity of the SIS′ domains was supported by the analysis of convergent and discriminative analysis. In the current study, the SIS was sensitive in discriminating differences in health status between patients with varying severity of stroke, as defined by disability (BI) and impairment (NIHSS) score. This is in agreement with different studies concerning the relation between physical disabilities and QOL; namely Carod-Artal et al.¹⁶; Sturm et al.¹⁷ Haache et al.¹⁸; Kwok et al.¹⁹; and  Fischer et al.²⁰ found that a higher NIHSS score on admission was independent predictor of impaired QOL. In contrast, Williams et al.²¹ and Pan et al.² found poor association between NIHSS and SS-QOL domains.

Consistent with prior reports of decreased HRQOL for women^16,22,3,23,1 we found that our female patients had lower SIS score compared to men but it could not reach a significant level. Patel et al.¹ attributed lower subjective well-being in women to a socio-cultural effect of women routinely taking responsibility for household management until they reach an advanced age and once they are disabled by stroke, it may be more difficult for their male partners to look after them, hence reducing their HRQOL.

In our study we found right hemispheric lesions to be non-significantly associated with poor QOL score. There are contradictory results regarding the effect of side of stroke on HRQOL.  Few reports, like ours^24,1 found HRQOL to be worse in those with right-sided lesions and this is attributed to neurological disturbances associated with right sided lesions including neglect, anosognosia, and spatial disorientation which may have devastating effects on social functioning and thus on HRQOL¹.  On contrary, Nichols-Larsen et al.³ found that stroke patients with left brain lesion would be most likely to experience communication difficulties secondary to damage of left hemisphere with unilateral speech representation. Whereas, Hopman and Verner²² reported that the side of stroke had little impact on the HRQOL outcomes. Regarding the effect of stroke type on HRQOL, we found non significant differences in SIS between both ischemic and hemorrhagic stroke patients. This is in agreement with previous reports where no differences between ischemic and hemorrhagic stroke on HRQOL were detected^24,25,3,1

The association between depression and QOL has been reported previously^{16,25,26,27,19,28,1}. In accordance, we found that HRQOL was significantly lower in patients with moderate-severe depression than those without depression. Consistent with affection of QOL with depression, Moon et al.²⁹ found that depression symptoms in acute phase of stroke were of importance in predicting low QOL 2 months after stroke. Furthermore, Haache et al.¹⁸ demonstrated that poststroke depression predicted the outcomes of HRQOL. In support, Jönsson et al.²⁶ concluded that intervention targeting mood might improve QOL regardless of physical disability.

                In the current study, the discriminated validity of SIS was also demonstrated in the pattern of changes in scores between the first and third month’s scores. We found that patients are changing significantly in all dimensions except memory, emotion and communication. Duncan et al.⁵ found that the changing in their patients were in all dimensions of SIS except emotions. Williams et al.²¹ demonstrated that SS-QOL domains were responsive to patient-reported change between 1 and 3 months except vision domain. Hopman and Verner²² using SF-36 HRQOL in 85 stroke patients, found that after one month there were improvements in all 8 domains of the SF-36, with 5 attaining statistical significance, and after 6 months, 4 domains continued to improve, with one attaining significant level. Lastly, QOL was assessed using the SIS in 93 stroke patients with therapeutic exercise, Studenski et al.³⁰ found that the patients with interventional exercise demonstrated improved more than usual care in strength, emotion, social participation, and physical function.

Regarding convergent validity of SIS in the current study, HRQOL in the area of overall physical functioning (subscales1, 5, 6, 7) was significantly influenced by age, co-morbidities, social score and the degree of impairments in NIHSS. The decreasing HRQOL in older age was reported in other studies^31,25,18. The last authors explained this by increasing disabilities and health problems in old age. In contrast, Carod-Artal et al.¹⁶ found that older age was not correlated with low QOL. Surprisingly, Patel et al.¹ showed that younger subjects reported worse HRQOL at 1 and 3 years after stroke and this may be due to either younger subjects being less able to cope psychologically with the stroke than older subjects, or they may have higher expectations of health, reflecting one of the definitions of HRQOL as the gap between our expectations of health and our experience of it.

In our study, the most common multiple co-morbidities were osteoarthosis, diabetes mellitus, and cardiac diseases that might be expected to impact physical function more than other HRQOL areas. In accordance with our results, Nichols-Larsen et al.³ and Patel et al.¹ in their study upon HRQOL  in stroke patients found that co-morbidities was significantly affected physical functioning in SIS (Version 3.0) and SF-36 respectively. The last authors found associations between stroke risk factors including diabetes, hypertension, and ischemic heart disease and HRQOL after stroke and they mentioned that these associations may be due to the additive effects of the conditions themselves, and emphasize the hypothetical potential of improving HRQOL after stroke by managing the risk factors more effectively after stroke.

                In contrast, we found that there were poor correlations between the clinical characteristics and remaining domains of the SIS. This is in agreement with Duncan et al.⁵; William et al.²¹; and Nichols-Larsen et al.³, who found a lack of association among many of the clinical characteristics and HRQOL domains other than physical domain. The reasons that might explain the poor performance of emotion domain are that the patients were asked to rate their emotional domain relative to the past week only and emotions scores are expected to exhibit more short-term variability than physical scores⁵. Furthermore, Nichols-Larsen et al.³ postulated that the perceptions of stroke survivors about changes in their thinking and emotions may be less accurate than their perceptions about physical limitations and this explanation is consistent with proxy ratings where others have rated stroke survivors HRQOL lower than survivors did.

                Maintenance of healthy social relationships may be one of the most important and salient influence of stroke on QOL. For patients, themes that related to social relationships include social support; especially lack of support from significant others, feelings of frustration resulting from increased dependence on others, and difficulty communicating²⁸. In the present study, we found significant correlations between social role participation of the SIS and other clinical variables including social score. Our findings are consistent with other researches postulated that social support was one of the primary influences on poststroke QOL^{32,21,33,34,28}.            

In conclusion, the findings of the current study emphasize the impact of and the need to take demographic and personal characteristics, including age, gender, co-morbidities, and social relations into account in the planning of poststroke rehabilitation programs. This study also highlights the importance of comprehensive scale evaluation during recovery after stroke that may facilitate a better understanding of individual needs and thereby, planning for programming during recovery. The SIS is a single stroke outcome measure that aims to effectively assess the various domains important in determining HRQOL in stroke patients.     

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