|Year : 2021 | Volume
| Issue : 1 | Page : 47-52
Burden and quality of life among caregivers of patients with parkinson's disease
Mariamma P Baby1, Selva Titus Chacko2, Bala Seetharaman3, Anil Kumar Patil4
1 Staff Nurse, Southwest Memorial Hermann Hospital, Houston, United States of America
2 Former Professor & Dean, College of Nursing, Vellore, Tamil Nadu, India
3 Nursing Superintendent, Department of Neurological and Neurosciences, Christian Medical College, Vellore, Tamil Nadu, India
4 Associate Professor, Department of Neurological and Neurosciences, Christian Medical College, Vellore, Tamil Nadu, India
|Date of Submission||13-May-2020|
|Date of Decision||03-Nov-2020|
|Date of Acceptance||03-Feb-2021|
|Date of Web Publication||07-Jul-2021|
Mrs. Mariamma P Baby
Southwest Memorial Hermann Hospital, Houston
United States of America
Source of Support: None, Conflict of Interest: None
Parkinson's disease (PD) is the second most common neurodegenerative disease which affects not only the patients but also the caregivers due to the progressive nature of the disease. A quantitative descriptive research approach was used to assess the burden and quality of life (QOL) among caregivers of patients with PD. A total of 72 caregivers were enrolled using total enumerative sampling technique. Data were collected using Zarit burden interview scale and PD Questionnaire-Carer QOL scale. The findings revealed that majority (52.8%) of the caregivers were female. The mean burden score was 26.63 ± 17.09. Majority (45.84%) of them had less burden. Poor QOL was experienced by 25% of caregivers. Positive correlation was found between burden and QOL (r = 0.608; P < 0.001). Significant association was found between selected sociodemographic variables of caregivers such as education, occupation, locality, total number of children, hours spent in caregiving and comorbidities with their level of burden and QOL. Among the clinical variables of patients, activities of daily living were found to have significant association with burden (P = 0.005; P < 0.01) and QOL (P = 0.002; P < 0.01). Knowledge and understanding of caregivers' burden and QOL can provide insights into how nurses can support and empower caregivers to enhance their QOL and that of their care recipients.
Keywords: Burden, caregivers, Parkinson's disease, quality of life
|How to cite this article:|
Baby MP, Chacko ST, Seetharaman B, Patil AK. Burden and quality of life among caregivers of patients with parkinson's disease. Indian J Cont Nsg Edn 2021;22:47-52
|How to cite this URL:|
Baby MP, Chacko ST, Seetharaman B, Patil AK. Burden and quality of life among caregivers of patients with parkinson's disease. Indian J Cont Nsg Edn [serial online] 2021 [cited 2021 Aug 1];22:47-52. Available from: https://www.ijcne.org/text.asp?2021/22/1/47/320825
| Introduction|| |
Parkinson's disease (PD) is a progressive neurodegenerative disorder, first described in the year 1817 by Dr. James Parkinson. PD affects approximately 6.3 million people in the world. Although it generally develops after the age of 65 years, about 15% of people with the condition develop 'young onset' PD even before reaching 50 years. This chronic debilitating condition results from the loss of cells in the brain that produces dopamine, a chemical that controls the body movements. The disease is characterised most frequently by tremors, muscle rigidity and slowness of movement.,
PD is a universal disorder, with a crude incidence rate of 4.5–19 per 100,000 population in a year. Majority of the studies reported a crude prevalence (including male and female across the entire age group) between 100 and 200 per 100,000 persons. Bharucha et al. found a high prevalence of PD among the small Parsi community in Mumbai, though India has a low prevalence rate. Although early-onset PD and familial cases have been described from India, no genetic mutations have been identified.
Advancing disease is found to erode all functional abilities, causing autonomic dysfunction, musculoskeletal deformities, sensory symptoms, sleep disturbances, dermatologic abnormalities and psychiatric manifestations. Although no treatment prevents disease progression, pharmacotherapy is found to control symptoms, maintain patient's independence and slow the progression. Eventually, medication loses effectiveness, patient's disability increases and care becomes palliative. As the condition progresses, detrimental effect is seen on the caregivers. It has direct implications upon their quality of life (QOL), as more time and energy are spent on the caregiving process.
The patients' caregivers perform a wide range of tasks and spend many hours a day caring. Caregivers face huge responsibilities and their future is uncertain as the disease progresses and prognosis is variable, making the amount of care needed unpredictable. As a consequence, the impact of PD on patients is of great importance, but also the impact on caregivers and caring for the caregiver becomes crucial. Challenges for PD caregivers also include financial burden and other long-term complications, such as lack of family support and competing role responsibilities, such as caring for children, elderly parents or spouses with PD. Caretakers face even greater burden from mental stress caused by worrying about patient's safety than from physical stress., Advancement in medical therapies and technology has resulted in increased life expectancy of patients with chronic illnesses. Patients' expectations have increased not just regarding better health status but also for improved QOL. As the focus of health-care continues to change, QOL and outcome of professional care will emerge as one of the important indicators of quality care.
With the increase in lifespan, there has been a rise in PD patients worldwide. It is important as nurses to recognise that in treating these patients, we are serving primarily older adults, who have higher rates of comorbid conditions and the need to manage a population with multiple chronic conditions. Unlike other chronic illnesses, patients with PD are usually not admitted in hospital, with symptoms that can be managed at home owing to either cost of treatment or availability of health-care facilities, they tend to depend fully on caregivers. There is no cure for PD, and even the efficacy of available treatments such as medication and surgical intervention decreases with longer duration of the disease.
Caregivers' burden has been defined as a multidimensional response to the negative appraisal and perceived stress resulting from taking care of an ill individual. Caregiver burden threatens the physical, psychological, emotional and functional health of caregivers. It has been seen that caregivers frequently suffered from depression, used maladaptive coping strategies and had shown concern towards their own QOL.,
This prolonged duration of care can have an impact not only on the caregivers' health and well-being but also on the care of patients. Understanding and being aware of caregivers' burden will help nurses anticipate and offer appropriate care suggestions to the caregivers. Family participation in the care of patients is essential to obtain optimal outcomes in nursing care. Necessary interventions and programmes can be implemented by health personnel to reduce the burden and improve the QOL of the caregivers. Very few studies have addressed the impact of these conditions on the caregivers in an Indian setting. This study explores the caregivers' burden and QOL in taking care of PD patients.
The objectives of the study were
- To assess the burden and QOL among caregivers of patients with PD
- To determine the relationship between burden and QOL among caregivers of patients with PD
- To find the association between burden and QOL among caregivers of patients with PD, with selected sociodemographic and clinical variables.
| Methods|| |
A descriptive research design was used. Total enumerative sampling technique was used to enrol a sample of 72 caregivers of PD patients above the age of 18 years attending a tertiary super specialty hospital in South India. Caregivers with chronic comorbid conditions such as dementia or psychiatric illnesses and paid caregivers were excluded from this study. The sample size was calculated based on the statistical inputs (standard deviation = 16) taken from the pilot study. The calculated sample size was 61, and a total of 72 samples were recruited during the study period of 6 weeks.
The data collection instrument consists of two parts.
Part I had sociodemographic variables of caregivers of patients with PD which included age, sex, religion, marital status, education, occupation, locality, family income, relationship to patient, number of children, number of years spent in giving care to patients with PD, number of hours spent in giving care and any comorbidity. The sociodemographic variables and clinical variable of patients with PD included age, sex, education, occupation, comorbidity and duration of illness, duration of treatment, frequency of taking medications and any comorbidities. The staging of disease severity was measured by Modified Hoehn and Yahr staging scale. According to which the lowest score 0 denoted no evidence of disease, 1 – unilateral disease only, 1.5 – unilateral disease plus axial involvement, 2.0 – bilateral mild disease without impaired balance, 2.5 – mild bilateral disease with recovery on pull test, 3.0 – mild-to-moderate bilateral disease with some postural instability but physically independent, 4.0 – severe disease, but still able to walk or stand unassisted and 5.0 – wheelchair bound or bedridden unless aided. The activities of daily living (ADL) were measured by Modified Schwab and England ADL scale [Table 1].
Part II had Zarit Burden Interview scale and PD Questionnaire–Carer (PDQ-Carer) QOL measure for PD caregivers.
Burden of caregivers of patients with PD was assessed using the Zarit burden scale developed by Zarit et al. The reliability of Zarit burden interview was 0.89, and Cronbach's alpha was 0.93. The scale consists of 22 questions with five options to answer. The options were never, rarely, sometimes, quite frequently and always, which carried a score of 0, 1, 2, 3 and 4, respectively. There is a minimum score of 0 and a maximum score of 4. The total score ranged from 0 to 88. A high score indicates higher levels of burden. The scale has five domains: burden in relationship (6 items), emotional well-being (7 items), social and family life (4 items), finances (1 item) and loss of control over one's life (4 items). The scoring of the Zarit-Burden interview scale was interpreted as follows: less burden (0–20), mild-to-moderate burden (21–40), moderate-to-severe burden (41–60) and severe burden (61–88). Standardised version of the tool in Hindi, Bengali, Tamil and Malayalam was provided by the Mapi Research Trust.
PD QOL – carer (PDQ-Carer) scale was used to measure the QOL among caregivers of patients with PD. The reliability of the PDQ-Carer tool was 0.94 and internal validity Cronbach's alpha was 0.89. The scale consists of 29 items rated on a five-point Likert scale, containing four domains that are social and personal activities (6 items), anxiety and depression (6 items), self-care (5 items) and stress (6 items) (Morley et al., 2013). Each dimension of QOL is calculated as a scale from 0 to 100, 0 = no problem at all and 100 = maximum level of problem. Overall scoring of QOL was done using percentile score and is as follows: very good QOL (0–17), good QOL (18–27), fair QOL (28–50) and poor QOL (>50). The instrument was translated into Hindi, Bengali, Tamil and Malayalam and tested by forward and back translation into English and proofread.
Data collection procedure
The study was conducted after the approval from the College of Nursing Research Committee. Permission was obtained from heads of the concerned departments. Informed written consent was obtained from study participants before data collection. Privacy of the participants and confidentiality of information were maintained throughout the study.
The sociodemographic variables of the caregivers and patients with PD were collected by the investigator using interview technique. Clinical data of patients with PD were collected partly from the medical records, treating physician and interview. Questionnaires on burden and QOL were given to caregivers of patients with PD from Neurology OPD, Geriatric clinic and Neurology wards. Data were collected from Monday to Friday between 7.30 am and 8.30 pm and on Saturday from 7.30 am to 12.30 pm. The purpose of the study was explained in a language understandable to them, and they were given an information sheet regarding the purpose, choice of participation, benefits, risks and confidentiality. They were given around 30 min to answer the questionnaire, and if any doubts arose, they were requested to ask the researcher. The filled in questionnaires were collected back by the investigator after making sure that all the questions were answered.
Descriptive and inferential statistics were used to analyse the data using the SPSS Statistics for Windows, Version 17.0. Chicago: SPSS Inc. The level of significance was set at 0.05 for the study. Descriptive statistics were used to summarise the demographic, clinical variables, caregiver burden scores and QOL. Spearman's correlation was used to find the relationship between burden and QOL. Chi-square or Fisher's exact test was used to signify the association between caregiver burden and QOL with demographic and clinical variables of caregivers and patients with PD.
| Results and Discussion|| |
Analysis of the variables in the present study revealed that the greatest number (38.8%) of caregivers belonged to the age group of 31–45 years followed by 30.6% in the age group of 46–60 years. The mean age group of caregivers was 45.74 ± 13.83. In a similar study done by Agrawal et al., mean age group of caregivers was 44.63 ± 14.27. The majority (52.8%) in the current study were female caregivers, 86.1% were married and 55.6% were graduate and above. Nearly 84.7% belonged to Hindu faith. 62.5% belonged to a joint family, 68% from urban area, 34.7% of them earned more than >Rs. 25,000 per month. 47.2% of caregivers were adult children (daughter, son, daughter in law) while 33.3% of them were a patient's wife. Contrary to these study findings, Kelly et al. among Australian PD caregivers showed that 84% of the caregivers were spouses or partners and 13% of them were patient's children. In the current study, 93.1% of them had fewer than three children, 7% of caregivers spent <1 year in giving care, 58.3% had spent 1–5 years in giving care and 19.4% of the caregivers gave care for 6–10 years. Furthermore, 15.3% gave care for more than 10 years. This finding is supported by the study done by Parrish, et al., in the United States where 36% of the caregivers provided care for 3–5 years, 25% had provided care for between 6 and 10 years and 10% of caregivers for 11 years or more. 61.6% of them spent 4 h per day or less giving care. This study also revealed that 55.6% of the caregivers had no comorbidity. However, 8.3% had hypertension, 6.8% suffered from diabetes mellitus, 4.2% had both hypertension and diabetes mellitus and 24.7% had other illnesses, such as joint pain, hypothyroidism, history of previous surgeries, asthma or cardiac diseases. A study done by Wandrekar et al. revealed that ill health of caregivers had significant relationship with the burden score. A study done by Schrag et al. also stated that 40% of the caregivers' health was affected due to giving care to patients with PD. Parrish et al. in his study reported that 73% of the caregivers had significant health problems. Regarding the sociodemographic and clinical data of patients with PD in this study, majority (52.8%) of the patients were over 60 years old and 65.3% were male, 63.9% of the patients with PD had <5 years of illness, 48.6% had no comorbidity and 72.3% had <5 years of treatment, according to Hoehn and Yahr staging of disease [Figure 1].
In the current study, 52.8% of PD patients were in 2nd and 3rd stage of disease. In the early stages of PD, medications help the patient to be functionally independent. As the disease progresses, medication treatment becomes less effective and caregiving becomes full time., Sanyal et al. also stated that motor imbalances with disability and severity of disease were the main factors which contributed to burden and stress in caregivers, and advanced stages of disease were associated with increased feelings of burden, social and financial status disruption. Analysis of studies on burden of caregivers of patients with PD done by Leiknes, et al. stated that advancing stage of PD along with functional disability contributed to caregiver burden. Hence, staging of disease and functional status are of utmost importance while planning care for the PD patient. The current study revealed that majority (48.60%) of PD patients had ADL score of 80%–100%, that is they were completely independent in most chores, 45.80% had ADL score of 40%–70%, that is they were not completely independent and needed support and more time to do the same task and 5.60% had ADL score of 0%–30%, that is total dependence on the caregivers for most of the task. Therefore, about half the proportion of the study patients were either partially dependent or completely dependent on caregiver for their ADL.
Burden among caregivers was analysed using the Zarit caregiver burden interview scale. The study findings revealed that 45.84% of caregivers had least burden and 36.11% had mild-to-moderate burden [Figure 2].
|Figure 2: Distribution of caregivers of patients with PD according to the burden scores|
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Oguh et al. stressed the fact that there is high prevalence of caregiver stress in taking care of PD patients. Kim et al. also reported that the caregivers of PD experienced high levels of burden comparable to the caregivers' burden in stroke and caregivers' burden in general chronic disease. However, the mean burden score was 26.63 ± 17.09 (maximum 88) revealing that the burden perceived by caregivers in this study was less. In a similar study done by Edwards and Reuttiger, the mean burden score was also found to be 23. In the Indian context where largely informal caregivers play a crucial role, caregiving can be viewed as a positive coping mechanism to overcome burden and stress. This also highlights the fact that caregivers value relationship much more than their burden in life. The experiences shared by the caregivers highlight the fact that burden is an inevitable part of the caregiving process, one such experience shared by the caregiver stated 'my dreams are all broken, my only hope was my son who would 1 day save the family from hardships but now he is disabled and I have almost spent all the money that I had for his treatment, I help him in taking bath, he has his food by himself, but very slowly, now and then I need to help him out with his other activities. Why does he suffer from this illness? It has made our life difficult'. Another important point is that the proportion of individuals with PD who were independent in ADL was almost the same as the proportion of caregivers who perceived lesser burden. This observation reveals that dependence in ADL is a vital factor influencing perception of burden.
In the present study, QOL among caregivers was assessed using PDQ-Carer. The study revealed that 26.39% of them had very good QOL, 25% of them had good QOL, 23.61% of them had fair QOL and 25% of them had poor QOL [Figure 3]. Martinez-Martin et al. highlighted the fact that the QOL was lower in caregivers of PD patients compared to the general population. Contrary to this statement, in this study, more than half the proportion of caregivers perceived good or very good QOL.
|Figure 3: Distribution of caregivers of patients with PD in relation to their quality of life|
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There was a significant positive correlation found between burden and QOL (r = 0.608). The degree of significance (P < 0.001) indicates that the burden score is directly related to the PDQ score. As the burden score increased, PDQ score also increased, signifying poor QOL with more perceived burden [Figure 4].
This finding is in harmony with the study done by Martinez-Martin et al., where there is a significant correlation between QOL and caregivers' burden. Morimoty et al. and Peters et al. in their studies reported that a strong relationship existed between worsening QOL with increased caregiver burden among caregivers of patients with chronic illness.
Significant association was found between burden and sociodemographic variables of caregivers such as religion (P = 0.031), education (P = 0.013), locality (P = 0.015), comorbidities (P = 0.038) and total number of children (P = 0.010) at P < 0.05. Significant association was also seen between burden and type of occupation (P = 0.000) and number of hours spent in giving care (P = 0.000) at P < 0.001.There is a significant association seen between burden and ADL (P = 0.005). This was similar to other study results which showed mobility level and duration of illness correlated with caregiver burden. No association was observed between caregiver burden and patient and caregiver demographics in a systematic review of articles on caregiver burden in PD. Significant association was found between QOL and sociodemographic variables of caregivers such as education (P = 0.022), occupation (P = 0.011), marital status (P = 0.031), relationship with patients (P = 0.014), total number of children (P = 0.026) at (P < 0.05) and number of hours spent in giving care (P = 0.001; P < 0.01).There is a statistically significant association between QOL and clinical variables such as comorbidity (P = 0.001), ADL (P = 0.002; P < 0.01) and duration of treatment (P = 0.022; P < 0.05). In another study, higher monthly income correlated to higher QOL of caregivers of PD whereas monthly expenditure on treatment or number of dependents did not have a relationship to QOL.
Statistically, the impact of caregiving can be seen among the caregivers of patients with PD, even though cultural variances can be seen in the act of caregiving. Caregiving was seen as a responsibility rather than burden. There were multiple factors such as economic status, support system available, staging of the disease, limitations on ADL and pharmacological management which were associated with burden and poor QOL and when managed can lead to better outcomes in terms of QOL.
| Conclusion|| |
Although caregivers reported less burden, the study findings have revealed that there is a positive correlation between burden and QOL among caregivers of patients with PD. PD patients suffer from motor and non-motor symptoms and with the progression of the disease, rehabilitative and supportive management becomes crucial. Caregivers play a key role in management and care of patients with PD. Caregivers who seek minimal or no help at all for their own illness from the health-care providers in turn become 'hidden patients'. Comprehensive management strategies can be developed for both patients and caregivers.
Nurses can act as liaison between the physician and the caregivers. They can ensure that caregivers also get the care they need. The nurse can educate the caregivers and the patient and provide information regarding the illness, management and prognosis. The nurse can also help in mentally preparing them for the challenges that lay ahead of them, encouraging them to seek social support and interventions such as psychoeducation therapy, behavioural therapy, guidance and counselling. A nurse-led clinic can provide comprehensive follow-up care to PD patients and their caregivers, thereby improving the QOL of the caregiver and the care recipient.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Lannon MC, Thomas CA, Bratton M, Jost MG, Lockhart Pretti P. Comprehensive care of the patient with Parkinson's disease. J Neurosci Nurs 1986;18:121-31.
Bloem BR, Hausdorff JM, Visser JE, Giladi N. Falls and freezing of gait in Parkinson's disease: A review of two interconnected, episodic phenomena. Mov Disord 2004;19:871-84.
Bharucha NE, Bharucha EP, Bharucha AE, Bhise AV, Schoenberg BS. Prevalence of Parkinson's disease in the Parsi community of Bombay, India. Arch Neurol 1988;45:1321-3.
Singhal B, Lalkaka J, Sankhla C. Epidemiology and treatment of Parkinson's disease in India. Parkinsonism Relat Disord 2003;9 Suppl 2:S105-9.
Peters M, Fitzpatrick R, Doll H, Playford ED, Jenkinson C. Patients' experiences of health and social care in long-term neurological conditions in England: A cross-sectional survey. J Health Serv Res Policy 2013;18:28-33.
Dyck C. Who cares for the caregiver? Parkinsonism Relat Disord 2009;15 Suppl 3:S118-21.
Roland KP, Jenkins ME, Johnson AM. An exploration of the burden experienced by spousal caregivers of individuals with Parkinson's disease. Mov Disord 2010;25:189-93.
Tan SB, Williams AF, Morris ME. Experiences of caregivers of people with Parkinson's disease in Singapore: A qualitative analysis. J Clin Nurs 2012;21:2235-46.
Zarit SH, Reever KE, Bach-Peterson J. Relatives of the impaired elderly: Correlates of feelings of burden. Gerontologist 1980;20:649-55.
Serrano-Aguilar PG, Lopez-Bastida J, Yanes-Lopez V. Impact on health-related quality of life and perceived burden of informal caregivers of individuals with Alzheimer's disease. Neuroepidemiology 2006;27:136-42.
Papastavrou E, Kalokerinou A, Papacostas SS, Tsangari H, Sourtzi P. Caring for a relative with dementia: Family caregiver burden. J Adv Nurs 2007;58:446-57.
Goetz CG, Poewe W, Rascol O, Sampaio C, Stebbins GT, Counsell C, et al
. Movement disorder society task force report on the Hoehn and Yahr staging scale: Status and recommendations. Mov Disord 2004;19:1020-8.
Agrawal V, Goyal V, Shukla G, Behari M. Predictors of caregivers' burden of Parkinson's disease in India: Experience of a tertiary care center in India. Res Rev Parkinsonism 2012;2:59-65.
Kelly DH, McGinley JL, Huxham FE, Menz HB, Watts JJ, Iansek R, et al
. Health-related quality of life and strain in caregivers of Australians with Parkinson's disease: An observational study. BMC Neurol 2012;12:1-7.
Parrish M, Parrish M, Giunta N, Adams S. Parkinson's disease caregiving: Implications for care management. Care Manag J 2003;4:53-60.
Wandrekar J, D'Souza N, Barretto M. Factors related to caregiver burden in caregivers of patients with Parkinson's disease in Mumbai, India. Int J Indian Psychol 2014;2:78-85.
Schrag A, Hovris A, Morley D, Quinn N, Jahanshahi M. Caregiver-burden in Parkinson's disease is closely associated with psychiatric symptoms, falls, and disability. Parkinsonism Relat Disord 2006;12:35-41.
Hoehn MM, Yahr MD. Parkinsonism: Onset, progression, and mortality. 1967. Neurology 1998;50:318.
Jankovic J, Rajput AH, McDermott MP, Perl DP. G. Parkinson study, the evolution of diagnosis in early Parkinson disease. Arch Neurol 2000;57:369-72.
Martinez-Martin P, Arroyo S, Rojo-Abuin JM, Rodriguez-Blazquez C, Frades B, de Pedro Cuesta J, et al
. Burden, perceived health status, and mood among caregivers of Parkinson's disease patients. Mov Disord 2008;23:1673-80.
Sanyal J, Das S, Ghosh E, Banerjee TK, Bhaskar LV, Rao VR. Burden among Parkinson's disease care givers for a community based study from India. J Neurol Sci 2015;358:276-81.
Leiknes I, Lien UT, Severinsson E. The relationship between caregiver burden, demographic variables, and the clinical characteristics of patients with Parkinson's disease – A systematic review of studies using various caregiver burden instruments. Open J Nurs 2015;5:855-77.
Oguh O, Kwasny M, Carter J, Stell B, Simuni T. Caregiver strain in Parkinson's disease: National Parkinson Foundation Quality Initiative study. Parkinsonism Relat Disord 2013;19:975-9.
Kim KS, Kim BJ, Kim KH, Choe MA, Yi M, Hah YS, et al
. Subjective and objective caregiver burden in Parkinson's disease. Taehan Kanho Hakhoe Chi 2007;37:242-8.
Edwards NE, Ruettiger KM. The influence of caregiver burden on patients' management of Parkinson's disease: Implications for rehabilitation nursing. Rehabil Nurs 2002;27:182-6, 198.
Martinez-Martin P, Schapira AH, Stocchi F, Sethi K, Odin P, MacPhee G, et al
. Prevalence of nonmotor symptoms in Parkinson's disease in an international setting; study using nonmotor symptoms questionnaire in 545 patients. Mov Disord 2007;22:1623-9.
Morimoty T, Schreiner AS, Asano H. Caregiver burden and heath related quality of life among Japanese stroke caregiver. Age Ageing 2003;32:218-23.
Leiknes I, Lien UT, Severinsson E. The relationship among caregiver burden, demographic variables, and the clinical characteristics of patients with Parkinson's disease – A systematic review of studies using various caregiver burden instruments. Open J Nurs 2015;5:855.
[Figure 1], [Figure 2], [Figure 3], [Figure 4]