RESEARCH ARTICLE
Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors in Osun, South-Western Nigeria Adebimpe O. Obembe*, Matthew M. Olaogun & Alaba E. Olalemi Department of Medical Rehabilitation, Faculty of Basic Medical Sciences, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
Abstract Background and purpose. Functional limitations in stroke survivors are sometimes associated with fatigue. This study assessed the functional limitations due to fatigue in community-dwelling stroke survivors undergoing physiotherapy. The differences in functional limitations due to fatigue were determined between sexes, stroke types, sides of affectation, age categories and levels of disability. Relationships between functional limitation due to fatigue and these variables were also determined. Methods. This was a cross-sectional study involving 63 stroke survivors (35 male survivors and 28 female survivors) with ages ranging from 45 to 79 years (mean = 53.68 ± 10.95 years). Functional limitation due to fatigue was assessed with the modified fatigue impact scale (MFIS). Modified Rankin scale was used to categorize the disability of the participants. Data were analysed using descriptive (mean, standard deviation, percentage and frequency) and inferential (Mann–Whitney U-test and Spearman correlation analysis) statistics. Significance was set at 0.05 α level. Results/findings. The mean MFIS score was 31.74 ± 12.39. Many participants (58.7%) had moderate functional limitations due to fatigue. The result of Mann–Whitney U-test showed significant difference in functional limitation due to fatigue between participants with slight disability and those with moderate disability (p = 0.000), with participants with moderate disability having higher MFIS scores (more functional limitations). There was also a significant correlation between functional limitation due to fatigue and level of disability (ρ = 0.625, p = 0.000). Discussion. Functional limitation due to fatigue occurs frequently in stroke survivors and is related to level of disability. Functional limitations due to fatigue should be assessed frequently in all stroke survivors with varying degrees of disability and the outcome should be considered during rehabilitation and retraining of physical function. Copyright © 2014 John Wiley & Sons, Ltd. Received 15 April 2013; Revised 18 February 2014; Accepted 3 May 2014 Keywords disability; fatigue; functional assessment; stroke *Correspondence Dr. Adebimpe Obembe, Department of Medical Rehabilitation, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria. E-mail: [email protected]
Published online 12 June 2014 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/pri.1596
Introduction Fatigue is common after stroke even in patients with good recovery (Lerdal et al., 2009). It can be defined 54
as a feeling of physical tiredness and lack of energy and is a common complaint after stroke (de Groot et al., 2003). Post-stroke fatigue (PSF) can be severe Physiother. Res. Int. 20 (2015) 54–59 © 2014 John Wiley & Sons, Ltd.
A. O. Obembe et al.
Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors
and it is experienced for months and years after the stroke and may be a frequently disabling condition (Choi-Kwon and Kim, 2011). Many stroke survivors have reported that fatigue is either their worst or one of their worst symptoms (Glader et al., 2002). Fatigue often manifests as both physical and mental lack of energy. It has been found to correlate significantly with measures of functional disability and neuropsyc \hologic problems (Van der Werf et al., 2001). Estimates of prevalence of PSF have been reported to range from 16% to 70% (Mead et al., 2011), depending on the population studied, how fatigue was identified and if some of the study population were depressed (McGeough et al., 2009). In a study involving Korean patients with fatigue before stroke, the severity of fatigue was reported to have increased after stroke, and PSF was more severe than that of patients without fatigue before the stroke (Choi-Kwon and Kim, 2011). Stroke survivors with less severe physical or cognitive disability after stroke tend to rate fatigue as a more severe symptom (van Zandvoort et al., 1998; Ingles et al., 1999). Stroke survivors who reported fatigue attributed more functional limitations to it in both physical and psychosocial (but not cognitive) domains than did control subjects with fatigue (Ingles et al., 1999). Conflicting evidence has been found in the relationships with personal factors such as sex and age (van Eijsden et al., 2012). Also, conflicting results have been found in the relationships of fatigue with stroke location or type (Lerdal et al., 2009). Fatigue interferes with the rehabilitation process and impairs the patient’s ability to regain functions lost because of the stroke (Glader et al., 2002). Also, physiotherapy may be limited by fatigue (Morley et al., 2005). PSF is still a relatively unexplored condition and it is often neglected (Vuletić et al., 2011). To our knowledge, fatigue and functional limitations due to fatigue in Nigerian stroke survivors have not been reported. Therefore, this study was designed to assess the functional limitations due to fatigue in stroke survivors undergoing physiotherapy and to determine the differences between sexes, age categories, stroke types, sides of affectation and levels of disability. Relationships between functional limitations due to fatigue and these variables were also determined.
Methods This was a cross-sectional study involving 63 community-dwelling stroke survivors undergoing outpatient Physiother. Res. Int. 20 (2015) 54–59 © 2014 John Wiley & Sons, Ltd.
physiotherapy. The participants were recruited consecutively between February and December 2012 as they became available on the basis of the study criteria from the two teaching hospitals in Osun State: Obafemi Awolowo University Teaching Hospitals Complex Ile-Ife and Ilesa units and Ladoke Akintola University of Technology Teaching Hospital, Osogbo. Participants fulfilled the following inclusion criteria: first time stroke with no other major medical, neurological or orthopaedic conditions than considered as stroke risk factors; no severe deficits in understanding and following simple verbal instructions; no limitations in activities of daily living prior to stroke onset; and the stroke survivors were able to walk independently with or without assistive aids (such as cane, walker). This is equivalent to scores of 0–3 on the modified Rankin scale (mRs) (van Swieten et al., 1988). Only independently ambulant stroke survivors were involved in this study to have a homogeneous group based on physical functioning. The study protocol was reviewed and approved by the Health Research Ethics Committee of the Institute of Public Health, Obafemi Awolowo University. The procedure was explained to the participants prior to assessment, and informed consent was obtained from each participant. Demographic (age and sex) and clinical (side of affectation) information were obtained directly from the participants and from their case records. Patients’ strokes were classified as hemorrhagic or ischemic from neurologists’ diagnoses, which included radiological investigations, and our clinical findings. On the basis of the heterogeneous nature of the study sample considering their ages and because many stroke survivors in south west Nigeria are older than 50 years (Ogun et al., 2005), participants were classified into two age categories, less than 50 years and more than 50 years. Functional limitation due to post-stroke fatigue was assessed with the modified fatigue impact scale (MFIS), which is a shortened version of the 40-item fatigue impact scale by Fisk et al. (1994) consisting of 21 items. It is a self-reported questionnaire used to assess the impact of fatigue on physical, cognitive and psychosocial functioning with a higher score indicating more of an impact. Participants were asked to rate on a Likert scale (range 0–4) how often they had experienced 21 problems due to fatigue during the last month. This score reflects functional limitation due to fatigue experienced within the previous month rather than a measure of the 55
A. O. Obembe et al.
Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors
level of fatigue (Frith and Newton, 2010). It took 3–5 min to complete the scale for each participant. Functional limitations of participants were categorized into three according to the severity as mild (MFIS scores of 8–21), moderate (MFIS scores of 22–42) and severe (MFIS scores of 43–61). The mRs was used to categorize the disability of the participants. It is widely used to assess global outcome after stroke. The scale describes six grades of disability after a stroke. A score of 0 denotes no symptoms at all, a score of 2 denotes slight disability, a score of 3 denotes moderate disability and a score of 5 denotes severe disability (Wilson et al., 2005). Descriptive statistics of mean, standard deviation, percentage and frequency were calculated for characteristics of the participants. Mann–Whitney U-test was used to determine the differences between groups (sex, age category, side of affectation, stroke type and levels of disability). Spearman correlation analysis was used to determine the correlation between functional limitation due to fatigue and selected variables (sex, age category, stroke type, side of affectation and levels of disability). The variables were examined for multicollinearity by means of Spearman correlation. In multiple regression analysis, only the factors that were significant in the bivariate correlation analysis were entered into the prediction model. Significance was set at 0.05 α level. All statistical analyses were carried out using Statistical Package for Social Sciences (SPSS) 16.0 (SPSS Inc., Chicago IL, USA).
Results This study recruited 63 (35 male survivors and 28 female survivors) stroke survivors whose ages ranged from 45 to 79 years (mean = 53.68 ± 10.95 years) with stroke duration ranging from 6 to 24 months (mean = 15.88 ± 4.81 months). Twenty one (33.3%) participants had slight disability (mRs score = 2) and 42 (66.7%) had moderate disability (mRs score = 3). The mean MFIS score for all the participants was (38.41 ± 11.72). Thirty seven (58.7%) participants had moderate functional limitations due to PSF (Table 1). There was no significant difference in functional limitations due to fatigue between male and female survivors, hemorrhagic and ischemic, left and right sided and between younger and older stroke survivors (p > 0.05). There was, however, a significant difference between participants with slight disability and those 56
Table 1. Socio-demographic and clinical characteristics of participants N = 63 Variable
Value
Age, years (45–79), (mean ± SD) Stroke duration, months (6–24), (mean ± SD) Age category, years, n (%) ≤50 >50 Sex, n (%) Male Female Side of affectation, n (%) Right Left Stroke type, n (%) Hemorrhagic Ischemic MFIS score (8–61), (mean ± SD) Fatigue impact, n (%) Mild (8–21) Moderate (22–42) Severe (43–61) Level of disability Slight (mRs score = 2) Moderate (mRs score = 3)
53.68 ± 10.95 15.88 ± 4.81 28 (44.4%) 35 (55.6%) 35 (55.6%) 28 (44.4%) 38 (60.3%) 25 (39.7%) 27 (42.9%) 36 (57.1%) 37.74 ± 12.39 4 (6.3%) 37 (58.7%) 22 (34.9%) 21 (33.3%) 42 (66.7%)
SD, standard deviation; MFIS, modified fatigue impact scale; mRs, Modified Rankin scale.
with moderate disability (p = 0.000), with participants with moderate disability having higher MFIS scores (40.45 ± 10.73 vs. 24.86 ± 7.16), (Table 2). There was a high correlation between functional limitation due to fatigue and level of disability (ρ = 0.604, p = 0.000) Table 2. Mann–Whitney U-test showing comparison of functional limitations due to post-stroke fatigue between groups Minimum
Maximum
Mean ± SD
p
8 11
61 59
36.17 ± 12.81 41.21 ± 9.71
0.105
10 8
61 54
42.04 ± 11.13 35.69 ± 11.57
0.095
8 10
61 59
38.69 ± 12.89 37.92 ± 10.05
0.360
10 8
61 54
39.36 ± 12.12 37.66 ± 11.52
0.454
8 10
34 61
24.85 ± 7.16 40.45 ± 10.73
0.000
Sex Male Female Stroke type Hemorrhagic Ischemic Side of affectation Right Left Age category ≤50 years >50 years Level of disability Slight Moderate SD, standard deviation.
Physiother. Res. Int. 20 (2015) 54–59 © 2014 John Wiley & Sons, Ltd.
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Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors
and a low correlation with stroke type (ρ = 0.298, p = 0.018). The results of the Spearman correlation analysis among the variables are shown in Table 3. Bivariate analysis of the determinants of fatigue impact showed two significant determinants (sex and level of disability). Because there was no multicollinearity between these determinants, they were both included in the logistic regression (R2 = 0.391, F(2, 60) = 19.284, p = 0.000), (Table 4).
Discussion This study assessed the functional limitations due to fatigue in stroke survivors undergoing physiotherapy. The results of our study showed that most of the participants (93.7%) had moderate to severe functional limitations due to PSF. This shows that functional limitations due to fatigue occur frequently in Nigerian stroke survivors. Our finding is similar to those in the study by Jaracz et al. (2007) who reported that 90% of stroke survivors in their study demonstrated high level of fatigue in physical functioning. Only 22 (34.9%) stroke survivors in our study had severe functional limitations due to PSF. On the basis of 1-year follow-up, Schepers et al. (2006) reported that there is domination of physical fatigue in the early phase of stroke. Fatigue (severity and impact) was present in more than 60% of their patients 6 months and 1 year post-stroke. The results of this study did not show any significant difference in functional limitation due to fatigue between sexes, stroke types and sides of affectation. Other studies have also reported that the occurrence of fatigue or increased fatigue severity, duration and frequency in stroke survivors is not associated with several stroke-related variables, including demographic variables (such as age and gender), (Vuletić et al., 2011), stroke duration (Ingles et al., 1999; Van der Werf et al., 2001; Hoang et al., 2012) and types or severity of stroke (Ingles et al., 1999; Glader et al., 2002). The findings in these previous studies are similar to those of our study. The results of our study showed that women reported more functional limitations due to fatigue than men but there was no significant difference in MFIS scores between male and female participants. Contrary to our findings, relationship between sex and fatigue has been reported in previous studies (Glader et al., Physiother. Res. Int. 20 (2015) 54–59 © 2014 John Wiley & Sons, Ltd.
2002; Schepers et al., 2006). The reason for the difference in results may be that the instruments used in our study and these other studies assessed different concepts of PSF. Side of lesion (right hemisphere and left hemisphere) and stroke type (hemorrhagic and ischemic) were not related to fatigue impact in our study. This supports findings in previous studies (Ingles et al., 1999; Morley et al., 2005; Naess et al., 2005) that fatigue is not related to lesion side or location. Staub and Bogousslavsky (2001a) stated that recent neurobehavioral studies have highlighted an association between fatigue and brainstem and thalamic lesions. They reported that fatigue was found mainly in people with a brainstem infarct (54.5%), less often in people with subcortical infarct (37.5%) and rarely in people with cortical infarct (6.25%). However, they found no significant correlation between fatigue and stroke severity, lesion location and neurological impairment. The results showed that younger stroke survivors in our study had more functional limitations due to fatigue but there was no significant difference in MFIS scores between younger (≤50 years) and older stroke (>50 years) survivors. The reason may be that the demands of daily life are qualitatively different for younger stroke survivors compared with older stroke survivors, making fatigue more of an obstacle to accomplishing the required tasks (de Groot et al., 2003). This is contrary to findings in a previous study which suggested that fatigue impact is more in older stroke survivors (Jaracz et al., 2007). They supposed that older patients had decreased fitness prior to stroke. The reason for the difference in the results of our study and their study may be that their participants’ stroke was generally more acute (≥3 months) compared with that of our participants (≥6 months). Our study showed that stroke survivors with more disability were more limited in function because of fatigue. Furthermore, our results showed that level of disability had a good positive correlation with functional limitations due to fatigue. This is not consistent with findings in previous studies (Staub and Bogousslavsky, 2001a, 2001b), which showed that the severity of fatigue in stroke survivors without functional deficit or with mild functional and neurological deficits is greater than in stroke survivors with severe post-stroke disability. The relative lack of other sequelae may make fatigue a more salient post-stroke symptom; the expectation for things to return to normal is greater for 57
Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors
Table 3. Correlation matrix showing relationships among the variables
Age Age Sex Stroke type Side of affectation Level of disability Fatigue impact
Sex
Stroke type
Side of affectation
Level of disability
1 0.183 1 0.515* 0.043 0.060 0.025
1 0.074
1
0.112
0.209
0.131
0.086
1
0.442
0.192
0.298*
0.052
0.604*
*Spearman correlation is significant at p< 0.05.
Table 4. Regression analysis to show determinants of fatigue impact in stroke survivors Unstandardized Standardized coefficient coefficient Sex Level of disability
5.043 13.203
2.357 2.265
95% CI
p
0.327–9.758 0.037 8.674–17.733 0.000
2
Final regression model (R = 0.391, F(2, 60) = 19.284, p = 0.000).
stroke survivors with more subtle disabilities (de Groot et al., 2003). The reason for the difference in results may be that the two studies used instruments that assessed different concepts of PSF. The impact of fatigue may be more in stroke survivors with more disability because they have less function and are usually less physically active. We assessed functional limitations due to poststroke fatigue to have a better understanding of the factors that influence it so as to improve the strategies of physiotherapy interventions. Because fatigue following stroke may have several causative factors, the best treatment for PSF is uncertain (McGeough et al., 2009). Aiming treatment towards predisposing factors has been reported to be likely of most benefit (de Groot et al., 2003). There is often a sudden reduction in physical activity in stroke survivors as a direct result of neurological impairment, and the reduced physical inactivity may lead to decline in physical fitness (Duncan et al., 2012). The level of disability is an important factor in functional limitations due to PSF. Therefore, physiotherapists and other rehabilitation experts should consider the functional limitations due to fatigue in stroke survivors in the process of managing stroke survivors with residual disability. 58
A. O. Obembe et al.
The findings in our study may not be generalized to all stroke survivors because the participants could ambulate independently. Another limitation of this study was the sample bias, as the participants were recruited consecutively as they became available on the basis of the study criteria. Furthermore, this was a hospitalbased study. Authors therefore recommend that further studies address the problem of external validity. Functional limitation due to post-stroke fatigue has been understudied in Nigeria. Further research is necessary to explore other factors that may affect functional limitation due to fatigue in Nigerian stroke survivors with varying degrees of recovery. This study concluded that functional limitation due to fatigue occurs frequently after stroke and is related to the level of disability. Assessment of functional limitation is essential to have a better understanding of factors that may influence post-stroke fatigue; this understanding will enhance improvement or modification of physiotherapeutic intervention. Functional limitations due to fatigue should therefore be assessed frequently in all stroke survivors undergoing physiotherapy. The outcome should be taken into consideration during rehabilitation and retraining, taking cognizance of the level of disability.
REFERENCES Choi-Kwon S, Kim JS. Post stroke fatigue: an emerging, critical issue in stroke medicine. International Journal of Stroke 2011; 6(4): 328–336. Duncan F, Kutlubaev MA, Dennis MS, Greig C, Mead GE. Fatigue after stroke: a systematic review of associations with impaired physical fitness. International Journal of Stroke 2012; 7: 157–162. van Eijsden HM, van de Port IGL, Visser-Meily JMA, Kwakkel G. Poststroke fatigue: who is at risk for an increase in fatigue? Stroke Research and Treatment 2012; 863978. Fisk JD, Ritvo PG, Ross L, Haase DA, Marrie TJ, Schlech WF. Measuring the functional impact of fatigue: initial validation of the fatigue impact scale. Clinical Infectious Diseases 1994; 1(Suppl. 1): S79–S83. Frith J, Newton J. Fatigue impact scale occupational. Medicine 2010; 60(2): 159–159. Glader E, Stegmayr B, Asplund K. Poststroke fatigue. A 2-year follow-up study of stroke patients in Sweden. Stroke 2002; 33: 1327–1333. de Groot MH, Phillips SJ, Eskes GA. Fatigue associated with stroke and other neurologic conditions: implications for Physiother. Res. Int. 20 (2015) 54–59 © 2014 John Wiley & Sons, Ltd.
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Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors
stroke rehabilitation. Archives of Physical Medicine and Rehabilitation 2003; 84: 1714–1720. Hoang CL, Salle JY, Mandigout S, Hamonet J, MacianMontoro F, Daviet JC. Physical factors associated with fatigue after stroke: an exploratory study. Topics in Stroke Rehabilitation 2012; 19(5): 369–376. Ingles JL, Eskes GA, Philips SJ. Fatigue after stroke. Archives of Physical Medicine and Rehabilitation 1999; 80: 173–178. Jaracz K, Mielcarek L, Kozubski W. Clinical and psychological correlates of post stroke fatigue. Preliminary results. Neurologia i Neurochirurgia Polska 2007; 41(1): 36–43. Lerdal A, Bakken LN, Kouwenhoven SE, Pedersen G, Kirkevold M, Finset A, Kim HS. Poststroke fatigue—a review. Journal of Pain and Symptom Management 2009; 38(6): 928–949. McGeough E, Pollock A, Smith LN, Dennis M, Sharpe M, Lewis S, Mead GE. Interventions for post-stroke fatigue. Cochrane Database of Systematic Reviews 2009; 3: CD007030. Mead GE, Graham C, Dorman P, Bruins KS, Lewis SC, Dennis MS, Sandercock PA. Fatigue after stroke: baseline predictors and influence on survival. Analysis of data from UK patients recruited in the international stroke trial. PLoS One 2011; 6(3): e16988. Morley W, Jackson K, Mead GE. Post-stroke fatigue: an important yet neglected symptom. Age and Ageing 2005; 34(3): 313–313. Naess H, Nyland HI, Thomassen L, Aarseth J, Myhr KM. Fatigue at long-term follow-up in young adults with cerebral infarction. Cerebrovascular Diseases 2005; 20: 245–250.
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Ogun SA, Ojini FI, Ogungbo B, Kolapo KO, Danesi MA. Stroke in south west Nigeria: a 10-year review. Stroke 2005; 36: 1120–1122. Schepers VP, Visser-Meily AM, Ketelaar M, Lindeman E. Post stroke fatigue: course and its relation to personal and stroke-related factors. Archives of Physical Medicine and Rehabilitation 2006; 87: 184–188. Staub F, Bogousslavsky J. Fatigue after stroke: a major but neglected issue. Cerebrovascular Diseases 2001a; 12: 75–81. Staub F, Bogousslavsky J. Post-stroke depression or fatigue? European Neurology 2001b; 45: 3–5. van Swieten JC, Koudstaal PJ, Visser MC, Schouten HJ, van Gijn J. Interobserver agreement for the assessment of handicap in stroke patients. Stroke 1988; 19(5): 604–607. Van der Werf SP, van der Broek HL, Anten HW, Bleijenberg G. Experience of severe fatigue long after stroke and its relation to depressive symptoms and disease characteristics. European Neurology 2001; 45: 28–33. Vuletić V, Ležaić Z, Morović S. Post-stroke fatigue. Acta Clinica Croatica 2011; 50(3): 341–344. Wilson JTL, Hareendran A, Hendry A, Potter J, Bone I, Muir KW. Reliability of the modified Rankin scale across multiple raters: benefits of a structured interview. Stroke 2005; 36: 777–781. van Zandvoort MJ, Kappelle LJ, Algra A, De Haan EH. Decreased capacity for mental effort after single supratentorial lacunar infarct may affect performance in everyday life. Journal of Neurology, Neurosurgery, and Psychiatry 1998; 65: 697–702.
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Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors in Osun, South-Western Nigeria Adebimpe O. Obembe*, Matthew M. Olaogun & Alaba E. Olalemi Department of Medical Rehabilitation, Faculty of Basic Medical Sciences, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria
Abstract Background and purpose. Functional limitations in stroke survivors are sometimes associated with fatigue. This study assessed the functional limitations due to fatigue in community-dwelling stroke survivors undergoing physiotherapy. The differences in functional limitations due to fatigue were determined between sexes, stroke types, sides of affectation, age categories and levels of disability. Relationships between functional limitation due to fatigue and these variables were also determined. Methods. This was a cross-sectional study involving 63 stroke survivors (35 male survivors and 28 female survivors) with ages ranging from 45 to 79 years (mean = 53.68 ± 10.95 years). Functional limitation due to fatigue was assessed with the modified fatigue impact scale (MFIS). Modified Rankin scale was used to categorize the disability of the participants. Data were analysed using descriptive (mean, standard deviation, percentage and frequency) and inferential (Mann–Whitney U-test and Spearman correlation analysis) statistics. Significance was set at 0.05 α level. Results/findings. The mean MFIS score was 31.74 ± 12.39. Many participants (58.7%) had moderate functional limitations due to fatigue. The result of Mann–Whitney U-test showed significant difference in functional limitation due to fatigue between participants with slight disability and those with moderate disability (p = 0.000), with participants with moderate disability having higher MFIS scores (more functional limitations). There was also a significant correlation between functional limitation due to fatigue and level of disability (ρ = 0.625, p = 0.000). Discussion. Functional limitation due to fatigue occurs frequently in stroke survivors and is related to level of disability. Functional limitations due to fatigue should be assessed frequently in all stroke survivors with varying degrees of disability and the outcome should be considered during rehabilitation and retraining of physical function. Copyright © 2014 John Wiley & Sons, Ltd. Received 15 April 2013; Revised 18 February 2014; Accepted 3 May 2014 Keywords disability; fatigue; functional assessment; stroke *Correspondence Dr. Adebimpe Obembe, Department of Medical Rehabilitation, College of Health Sciences, Obafemi Awolowo University, Ile-Ife, Osun State, Nigeria. E-mail: [email protected]
Published online 12 June 2014 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/pri.1596
Introduction Fatigue is common after stroke even in patients with good recovery (Lerdal et al., 2009). It can be defined 54
as a feeling of physical tiredness and lack of energy and is a common complaint after stroke (de Groot et al., 2003). Post-stroke fatigue (PSF) can be severe Physiother. Res. Int. 20 (2015) 54–59 © 2014 John Wiley & Sons, Ltd.
A. O. Obembe et al.
Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors
and it is experienced for months and years after the stroke and may be a frequently disabling condition (Choi-Kwon and Kim, 2011). Many stroke survivors have reported that fatigue is either their worst or one of their worst symptoms (Glader et al., 2002). Fatigue often manifests as both physical and mental lack of energy. It has been found to correlate significantly with measures of functional disability and neuropsyc \hologic problems (Van der Werf et al., 2001). Estimates of prevalence of PSF have been reported to range from 16% to 70% (Mead et al., 2011), depending on the population studied, how fatigue was identified and if some of the study population were depressed (McGeough et al., 2009). In a study involving Korean patients with fatigue before stroke, the severity of fatigue was reported to have increased after stroke, and PSF was more severe than that of patients without fatigue before the stroke (Choi-Kwon and Kim, 2011). Stroke survivors with less severe physical or cognitive disability after stroke tend to rate fatigue as a more severe symptom (van Zandvoort et al., 1998; Ingles et al., 1999). Stroke survivors who reported fatigue attributed more functional limitations to it in both physical and psychosocial (but not cognitive) domains than did control subjects with fatigue (Ingles et al., 1999). Conflicting evidence has been found in the relationships with personal factors such as sex and age (van Eijsden et al., 2012). Also, conflicting results have been found in the relationships of fatigue with stroke location or type (Lerdal et al., 2009). Fatigue interferes with the rehabilitation process and impairs the patient’s ability to regain functions lost because of the stroke (Glader et al., 2002). Also, physiotherapy may be limited by fatigue (Morley et al., 2005). PSF is still a relatively unexplored condition and it is often neglected (Vuletić et al., 2011). To our knowledge, fatigue and functional limitations due to fatigue in Nigerian stroke survivors have not been reported. Therefore, this study was designed to assess the functional limitations due to fatigue in stroke survivors undergoing physiotherapy and to determine the differences between sexes, age categories, stroke types, sides of affectation and levels of disability. Relationships between functional limitations due to fatigue and these variables were also determined.
Methods This was a cross-sectional study involving 63 community-dwelling stroke survivors undergoing outpatient Physiother. Res. Int. 20 (2015) 54–59 © 2014 John Wiley & Sons, Ltd.
physiotherapy. The participants were recruited consecutively between February and December 2012 as they became available on the basis of the study criteria from the two teaching hospitals in Osun State: Obafemi Awolowo University Teaching Hospitals Complex Ile-Ife and Ilesa units and Ladoke Akintola University of Technology Teaching Hospital, Osogbo. Participants fulfilled the following inclusion criteria: first time stroke with no other major medical, neurological or orthopaedic conditions than considered as stroke risk factors; no severe deficits in understanding and following simple verbal instructions; no limitations in activities of daily living prior to stroke onset; and the stroke survivors were able to walk independently with or without assistive aids (such as cane, walker). This is equivalent to scores of 0–3 on the modified Rankin scale (mRs) (van Swieten et al., 1988). Only independently ambulant stroke survivors were involved in this study to have a homogeneous group based on physical functioning. The study protocol was reviewed and approved by the Health Research Ethics Committee of the Institute of Public Health, Obafemi Awolowo University. The procedure was explained to the participants prior to assessment, and informed consent was obtained from each participant. Demographic (age and sex) and clinical (side of affectation) information were obtained directly from the participants and from their case records. Patients’ strokes were classified as hemorrhagic or ischemic from neurologists’ diagnoses, which included radiological investigations, and our clinical findings. On the basis of the heterogeneous nature of the study sample considering their ages and because many stroke survivors in south west Nigeria are older than 50 years (Ogun et al., 2005), participants were classified into two age categories, less than 50 years and more than 50 years. Functional limitation due to post-stroke fatigue was assessed with the modified fatigue impact scale (MFIS), which is a shortened version of the 40-item fatigue impact scale by Fisk et al. (1994) consisting of 21 items. It is a self-reported questionnaire used to assess the impact of fatigue on physical, cognitive and psychosocial functioning with a higher score indicating more of an impact. Participants were asked to rate on a Likert scale (range 0–4) how often they had experienced 21 problems due to fatigue during the last month. This score reflects functional limitation due to fatigue experienced within the previous month rather than a measure of the 55
A. O. Obembe et al.
Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors
level of fatigue (Frith and Newton, 2010). It took 3–5 min to complete the scale for each participant. Functional limitations of participants were categorized into three according to the severity as mild (MFIS scores of 8–21), moderate (MFIS scores of 22–42) and severe (MFIS scores of 43–61). The mRs was used to categorize the disability of the participants. It is widely used to assess global outcome after stroke. The scale describes six grades of disability after a stroke. A score of 0 denotes no symptoms at all, a score of 2 denotes slight disability, a score of 3 denotes moderate disability and a score of 5 denotes severe disability (Wilson et al., 2005). Descriptive statistics of mean, standard deviation, percentage and frequency were calculated for characteristics of the participants. Mann–Whitney U-test was used to determine the differences between groups (sex, age category, side of affectation, stroke type and levels of disability). Spearman correlation analysis was used to determine the correlation between functional limitation due to fatigue and selected variables (sex, age category, stroke type, side of affectation and levels of disability). The variables were examined for multicollinearity by means of Spearman correlation. In multiple regression analysis, only the factors that were significant in the bivariate correlation analysis were entered into the prediction model. Significance was set at 0.05 α level. All statistical analyses were carried out using Statistical Package for Social Sciences (SPSS) 16.0 (SPSS Inc., Chicago IL, USA).
Results This study recruited 63 (35 male survivors and 28 female survivors) stroke survivors whose ages ranged from 45 to 79 years (mean = 53.68 ± 10.95 years) with stroke duration ranging from 6 to 24 months (mean = 15.88 ± 4.81 months). Twenty one (33.3%) participants had slight disability (mRs score = 2) and 42 (66.7%) had moderate disability (mRs score = 3). The mean MFIS score for all the participants was (38.41 ± 11.72). Thirty seven (58.7%) participants had moderate functional limitations due to PSF (Table 1). There was no significant difference in functional limitations due to fatigue between male and female survivors, hemorrhagic and ischemic, left and right sided and between younger and older stroke survivors (p > 0.05). There was, however, a significant difference between participants with slight disability and those 56
Table 1. Socio-demographic and clinical characteristics of participants N = 63 Variable
Value
Age, years (45–79), (mean ± SD) Stroke duration, months (6–24), (mean ± SD) Age category, years, n (%) ≤50 >50 Sex, n (%) Male Female Side of affectation, n (%) Right Left Stroke type, n (%) Hemorrhagic Ischemic MFIS score (8–61), (mean ± SD) Fatigue impact, n (%) Mild (8–21) Moderate (22–42) Severe (43–61) Level of disability Slight (mRs score = 2) Moderate (mRs score = 3)
53.68 ± 10.95 15.88 ± 4.81 28 (44.4%) 35 (55.6%) 35 (55.6%) 28 (44.4%) 38 (60.3%) 25 (39.7%) 27 (42.9%) 36 (57.1%) 37.74 ± 12.39 4 (6.3%) 37 (58.7%) 22 (34.9%) 21 (33.3%) 42 (66.7%)
SD, standard deviation; MFIS, modified fatigue impact scale; mRs, Modified Rankin scale.
with moderate disability (p = 0.000), with participants with moderate disability having higher MFIS scores (40.45 ± 10.73 vs. 24.86 ± 7.16), (Table 2). There was a high correlation between functional limitation due to fatigue and level of disability (ρ = 0.604, p = 0.000) Table 2. Mann–Whitney U-test showing comparison of functional limitations due to post-stroke fatigue between groups Minimum
Maximum
Mean ± SD
p
8 11
61 59
36.17 ± 12.81 41.21 ± 9.71
0.105
10 8
61 54
42.04 ± 11.13 35.69 ± 11.57
0.095
8 10
61 59
38.69 ± 12.89 37.92 ± 10.05
0.360
10 8
61 54
39.36 ± 12.12 37.66 ± 11.52
0.454
8 10
34 61
24.85 ± 7.16 40.45 ± 10.73
0.000
Sex Male Female Stroke type Hemorrhagic Ischemic Side of affectation Right Left Age category ≤50 years >50 years Level of disability Slight Moderate SD, standard deviation.
Physiother. Res. Int. 20 (2015) 54–59 © 2014 John Wiley & Sons, Ltd.
A. O. Obembe et al.
Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors
and a low correlation with stroke type (ρ = 0.298, p = 0.018). The results of the Spearman correlation analysis among the variables are shown in Table 3. Bivariate analysis of the determinants of fatigue impact showed two significant determinants (sex and level of disability). Because there was no multicollinearity between these determinants, they were both included in the logistic regression (R2 = 0.391, F(2, 60) = 19.284, p = 0.000), (Table 4).
Discussion This study assessed the functional limitations due to fatigue in stroke survivors undergoing physiotherapy. The results of our study showed that most of the participants (93.7%) had moderate to severe functional limitations due to PSF. This shows that functional limitations due to fatigue occur frequently in Nigerian stroke survivors. Our finding is similar to those in the study by Jaracz et al. (2007) who reported that 90% of stroke survivors in their study demonstrated high level of fatigue in physical functioning. Only 22 (34.9%) stroke survivors in our study had severe functional limitations due to PSF. On the basis of 1-year follow-up, Schepers et al. (2006) reported that there is domination of physical fatigue in the early phase of stroke. Fatigue (severity and impact) was present in more than 60% of their patients 6 months and 1 year post-stroke. The results of this study did not show any significant difference in functional limitation due to fatigue between sexes, stroke types and sides of affectation. Other studies have also reported that the occurrence of fatigue or increased fatigue severity, duration and frequency in stroke survivors is not associated with several stroke-related variables, including demographic variables (such as age and gender), (Vuletić et al., 2011), stroke duration (Ingles et al., 1999; Van der Werf et al., 2001; Hoang et al., 2012) and types or severity of stroke (Ingles et al., 1999; Glader et al., 2002). The findings in these previous studies are similar to those of our study. The results of our study showed that women reported more functional limitations due to fatigue than men but there was no significant difference in MFIS scores between male and female participants. Contrary to our findings, relationship between sex and fatigue has been reported in previous studies (Glader et al., Physiother. Res. Int. 20 (2015) 54–59 © 2014 John Wiley & Sons, Ltd.
2002; Schepers et al., 2006). The reason for the difference in results may be that the instruments used in our study and these other studies assessed different concepts of PSF. Side of lesion (right hemisphere and left hemisphere) and stroke type (hemorrhagic and ischemic) were not related to fatigue impact in our study. This supports findings in previous studies (Ingles et al., 1999; Morley et al., 2005; Naess et al., 2005) that fatigue is not related to lesion side or location. Staub and Bogousslavsky (2001a) stated that recent neurobehavioral studies have highlighted an association between fatigue and brainstem and thalamic lesions. They reported that fatigue was found mainly in people with a brainstem infarct (54.5%), less often in people with subcortical infarct (37.5%) and rarely in people with cortical infarct (6.25%). However, they found no significant correlation between fatigue and stroke severity, lesion location and neurological impairment. The results showed that younger stroke survivors in our study had more functional limitations due to fatigue but there was no significant difference in MFIS scores between younger (≤50 years) and older stroke (>50 years) survivors. The reason may be that the demands of daily life are qualitatively different for younger stroke survivors compared with older stroke survivors, making fatigue more of an obstacle to accomplishing the required tasks (de Groot et al., 2003). This is contrary to findings in a previous study which suggested that fatigue impact is more in older stroke survivors (Jaracz et al., 2007). They supposed that older patients had decreased fitness prior to stroke. The reason for the difference in the results of our study and their study may be that their participants’ stroke was generally more acute (≥3 months) compared with that of our participants (≥6 months). Our study showed that stroke survivors with more disability were more limited in function because of fatigue. Furthermore, our results showed that level of disability had a good positive correlation with functional limitations due to fatigue. This is not consistent with findings in previous studies (Staub and Bogousslavsky, 2001a, 2001b), which showed that the severity of fatigue in stroke survivors without functional deficit or with mild functional and neurological deficits is greater than in stroke survivors with severe post-stroke disability. The relative lack of other sequelae may make fatigue a more salient post-stroke symptom; the expectation for things to return to normal is greater for 57
Functional Limitations due to Fatigue Among Independently Ambulant Stroke Survivors
Table 3. Correlation matrix showing relationships among the variables
Age Age Sex Stroke type Side of affectation Level of disability Fatigue impact
Sex
Stroke type
Side of affectation
Level of disability
1 0.183 1 0.515* 0.043 0.060 0.025
1 0.074
1
0.112
0.209
0.131
0.086
1
0.442
0.192
0.298*
0.052
0.604*
*Spearman correlation is significant at p< 0.05.
Table 4. Regression analysis to show determinants of fatigue impact in stroke survivors Unstandardized Standardized coefficient coefficient Sex Level of disability
5.043 13.203
2.357 2.265
95% CI
p
0.327–9.758 0.037 8.674–17.733 0.000
2
Final regression model (R = 0.391, F(2, 60) = 19.284, p = 0.000).
stroke survivors with more subtle disabilities (de Groot et al., 2003). The reason for the difference in results may be that the two studies used instruments that assessed different concepts of PSF. The impact of fatigue may be more in stroke survivors with more disability because they have less function and are usually less physically active. We assessed functional limitations due to poststroke fatigue to have a better understanding of the factors that influence it so as to improve the strategies of physiotherapy interventions. Because fatigue following stroke may have several causative factors, the best treatment for PSF is uncertain (McGeough et al., 2009). Aiming treatment towards predisposing factors has been reported to be likely of most benefit (de Groot et al., 2003). There is often a sudden reduction in physical activity in stroke survivors as a direct result of neurological impairment, and the reduced physical inactivity may lead to decline in physical fitness (Duncan et al., 2012). The level of disability is an important factor in functional limitations due to PSF. Therefore, physiotherapists and other rehabilitation experts should consider the functional limitations due to fatigue in stroke survivors in the process of managing stroke survivors with residual disability. 58
A. O. Obembe et al.
The findings in our study may not be generalized to all stroke survivors because the participants could ambulate independently. Another limitation of this study was the sample bias, as the participants were recruited consecutively as they became available on the basis of the study criteria. Furthermore, this was a hospitalbased study. Authors therefore recommend that further studies address the problem of external validity. Functional limitation due to post-stroke fatigue has been understudied in Nigeria. Further research is necessary to explore other factors that may affect functional limitation due to fatigue in Nigerian stroke survivors with varying degrees of recovery. This study concluded that functional limitation due to fatigue occurs frequently after stroke and is related to the level of disability. Assessment of functional limitation is essential to have a better understanding of factors that may influence post-stroke fatigue; this understanding will enhance improvement or modification of physiotherapeutic intervention. Functional limitations due to fatigue should therefore be assessed frequently in all stroke survivors undergoing physiotherapy. The outcome should be taken into consideration during rehabilitation and retraining, taking cognizance of the level of disability.
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