Quality of life and burden in caregivers for patients with Parkinson's ...

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Quality of life and burden in caregivers for patients with Parkinson’s disease: concepts, assessment and related factors Expert Rev. Pharmacoecon. Outcomes Res. 12(2), 221–230 (2012)

Pablo MartinezMartin*1,2, Carmen Rodriguez-Blazquez2,3 and Maria João Forjaz2,4 Alzheimer Disease Research Unit, CIEN Foundation–Reina Sofia Foundation, Carlos III Institute of Health, Alzheimer Center Reina Sofia Foundation, Cl. Valderrebollo, 5, 28031 Madrid, Spain 2 CIBERNED, Carlos III Institute of Health, Av. Monforte de Lemos, 5, 28029 Madrid, Spain 3 National Centre of Epidemiology, Carlos III Institute of Health, Av. Monforte de Lemos, 5, 28029 Madrid, Spain 4 National School of Public Health, Institute of Health Carlos III, Av. Monforte de Lemos, 5, 28029 Madrid, Spain *Author for correspondence: Tel.: +34 913852200 Fax: +34 913852118 [email protected] 1

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Caregivers of Parkinson’s disease patients face responsibilities stemming from providing assistance to a person, usually a family member, who suffers a progressively disabling disease characterized by both motor and nonmotor symptoms. These circumstances impact on the physical, emotional and psychosocial aspects of the caregivers’ lives and, therefore, on their quality of life (QoL). Studies have identified factors related to caregivers’ global QoL and health-related QoL, causing caregivers distress and affecting their QoL. These factors are related to patients’ and caregivers’ characteristics and may be classified as sociodemographic, psychological and disease related. Caregiver’s burden refers to the multiplicity of difficulties ensuing as a consequence of caring, including, for example, health problems, modification of habits, economic loss and QoL deterioration. Therefore, burden-related factors are also briefly reviewed. The implementation of effective interventions to preserve the caregiver’s wellbeing and allow the patients to remain at home and be properly assisted is a pragmatic consequence of this knowledge. Keywords : caregiver • caregiver burden • economic loss • health-related quality of life • Parkinson’s disease • quality of life

Parkinson’s disease (PD) is a neurodegenerative disorder characterized by motor impairments (tremor, rigidity, bradykinesia and postural instability) [1] and a wide variety of nonmotor symptoms, including autonomic dysfunction, sleep disturbances and mood and neuropsychiatric disorders [2] . As a disabling condition, PD progressively leads to patients’ lack of autonomy and worsening of quality of life (QoL). Patients with PD may need to be helped with their personal safety, medication compliance, activities of daily living and social involvement [3] . As the disease progresses, patients suffer increasing physical limitations, even for basic activities of daily living, and may have cognitive and psychiatric complications, resulting in highly demanding tasks for caregivers [4] . Most PD patients live in the community and are looked after by family members, who have to bear the burden of care. Families are the main providers of care and considerably reduce the strain on social health resources. This entails important economic implications [3,5] , as a high proportion of the disease costs due to caring are supported by the families themselves. 10.1586/ERP.11.106

Although caregivers in most chronic diseases may have a similar type and degree of burden [6] , the progressive nature of PD and the presence of symptoms that can constantly fluctuate on a daily or even hourly basis within the individual [4] represent special characteristics to PD caregiving. PD caregivers have been found to have increased depression scores, altered immune systems, which increases their susceptibility to physical illness, higher rates of psychiatric morbidity, increased burden, poor social lives and, in general, diminished QoL [4,7] than noncaregiver spouses or caregivers in other diseases. Purpose & structure of this paper

Caregivers’ QoL and burden have been subjects of growing interest among researchers, although in the context of PD, the number of published studies focused specifically on caregivers’ QoL is relatively small. The purpose of this paper is to review the state of the art in terms of concepts, assessment, related factors, costs and intervention programs on caregivers’ QoL and burden in the setting of PD. There is a need for

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Martinez-Martin, Rodriguez-Blazquez & Forjaz

a review that summarizes the key information and studies of QoL and burden in caregivers. This information could be very useful for researchers and clinicians who work on this issue. It will also help to identify directions for further studies. In this article, the conceptual frame of caregivers’ QoL and burden is established. We also carry out a critical review of the validated measures of caregivers’ QoL and burden. Factors that contribute to caregivers’ QoL deterioration and burden are the subject of another section, with a special emphasis on the studies on the caregiving determinants. The economic consequences of the caregiving process are also reviewed, and the article concludes with an overview of the interventions designed to alleviate the negative impact of caregiving and to support the caregiver’s role. Overview of concepts QoL

In a broad sense, QoL can be defined as “the individuals’ perception 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 concerns” [8] . In the context of health, we refer to a more restricted concept, ‘health-related quality of life’ (HRQoL), a multidimensional construct that has been defined as the patient’s “perception and self-evaluation regarding the impact of the disease and its consequences on his/her life” [9] in terms of physical, psychological and social aspects. Although most QoL and HRQoL studies in chronic health conditions are centered on the patient’s QoL [7] , research has been extended to consider the consequences of the disease on the caregivers’ lives. On the whole, and specifically in PD, supporting the functioning of caregivers and maximizing their QoL is important since poor caregivers’ QoL may impact negatively on patient functioning and QoL [3,7] . Caregiver burden

Caregivers can experience a multitude of difficulties and challenges that comprise the construct known as ‘caregiver burden’ [6,10] . This is a broad, multidimensional concept that describes the “physical, emotional and financial toll of providing care” [11] , and a distinction can be made between objective (physical and behavioral changes) and subjective (emotional aspects) burden [12] . A relationship between QoL and burden exists and factors influencing burden can have an effect on QoL, while QoL exerts an effect on burden. As such, caregivers’ burden and QoL share a core of similar causes and associations, although their concepts and components are not equivalent. Caregiver burden is directly affected by variables such as perceived social support, frequency of breaks and the quality of the caregiver–care recipient relationship [4] . Burden, in turn, is negatively associated with overall QoL. However, when controlling for other factors, burden is not a strong predictor of wellbeing. Caregivers’ QoL can be maintained at a reasonable level even when they are burdened [13] . In the referenced studies, caregiver burden is seen as a secondary appraisal whereas QoL act as the outcome of the caregiving process [4,13] . 222

Assessment of caregivers for patients with PD Measures of QoL

The assessment of caregivers’ QoL will enable quantification of their wellbeing and associated health status. This way, researchers and clinicians may determine differences with other populations, identify QoL determinants, estimate QoL changes over time or outcomes after intervention, and compare interventions. The most important and more frequently used measures of QoL used in PD caregivers will be presented, with a short description of the scale, their psychometric properties and reported mean values when applied to PD caregivers. QoL in PD caregivers may be assessed by means of specific or generic measures. The Scale of Quality of Life of Caregivers is a specific measure for caregivers [14] . The generic instruments can also be applied to the general population and allow comparison between different populations. The most frequently used HRQoL (or health-status) measures to assess PD caregivers are the Short Form (-36) Health Survey (SF-36) [15] , the EuroQol 5 Dimensions (EQ-5D) [16] , and the Brief Version of the World Health Organization QoL Instrument (WHOQOL-BREF) [17] . Scale of Quality of Life of Caregivers

This specific measure for evaluation of caregivers’ QoL is a relatively complex scale developed for quantifying the impact of chronic disabling disease on caregivers’ occupational, social and leisure activities [14] . It is made up of 16 items, answered in different response scales. The scale reaches a total score of 149 points and the higher the score, the higher the level of social adaptation and the lower the impact of the caregiving. Total score is standardized and four levels of distress may be determined according to the total score: no distress, 141–149 points; mild, 140–100 points; moderate, 99–86 points; and severe, 85 points or less. The scale does not specifically refer to PD and could potentially be used in other conditions as it only refers to “your relatives’ disease” [14] . However, it was validated in PD caregivers and it has been used for assessing caregivers’ QoL in several studies on PD [7,18–21] . The Scale of Quality of Life of Caregivers showed acceptable psychometric properties, characterized by satisfactory internal consistency (Cronbach’s a >0.80), and convergent validity with disease duration and stage, and mental and motor status [18] . PD caregivers showed a range of Scale of Quality of Life of Caregivers mean values across studies of 99.6–113.8 (standard deviation [SD]: 18.4–23.0) [7,18,21] . SF-36

The SF-36 assesses eight QoL dimensions, grouped into two components: the physical and the mental components [15] . The response format for the items differs across the scale and needs recoding to obtain the final scores. The overall scores range from 0 to 100, with higher scores indicating a better QoL. There are population norms by age and gender groups for several countries. It is a highly used measure, easy to apply, psychometrically sound, and either the SF-36 or shorter versions such as the SF-12 have been successfully used to assess caregivers for PD patients [10,22–25] . Although the SF-36 has been validated in the general population Expert Rev. Pharmacoecon. Outcomes Res. 12(2), (2012)

Quality of life & burden in caregivers for patients with Parkinson’s disease

and for many patient groups, there is no information about the psychometric properties of this instrument when applied specifically in PD caregivers. PD caregivers show higher values in the SF-36 physical component than in the mental component (mean [M] ± SD = 46.1 ± 10.3 and 43.1 ± 13.2, respectively) [10] . However, another study found similar values when using the SF-12 (51.6 ± 9.3 for the physical and 51.9 ± 8.6 for the mental component) [24] . EQ-5D

The EQ-5D was developed simultaneously in several European countries. It is an econometric measure that targets health status and preferences [16] . It is formed by five dimensions, rated on a 1–3 scale: mobility; self-care; usual activities; pain/discomfort; and anxiety/depression. The rating in the five dimensions forms a profile. There are 243 possible profiles or health states, corresponding to the possible combination of the three answers in the five dimensions. Each health-state profile, in turn, is associated with a social tariff or index value. The index value is anchored on 0 (dead) and 1 (perfect health), although it can also take negative values, which represent health states considered worse than death [16] . The EQ-5D also includes a visual analog scale (VAS) for self-rating the ‘current health state’ from 0 (‘worst imaginable health state’) to 100 (‘best imaginable health state’). The EQ-5D is frequently used to assess the QoL of PD caregivers [6,10,22,26–29] . The EQ-5D visual analog scale (EQ-VAS) was not sensitive to change in two studies reporting on intervention programs for PD caregivers [27,28] . There is a lack of validation studies of the EQ-5D in this specific population. The mean values of the EQ-5D index were 0.59–50.86 (SD: 0.20–20.33) and 60.1–79.0 (SD: 14.5–19.2) for the EQ-VAS [6,10,22,27–29] . WHOQOL-BREF

The WHOQOL-BREF is made up of 24 items grouped in four domains (physical health, psychological health, social relations and environment) plus two items (questions) for global QoL and general health [17] . Item response options range from 1 (very dissatisfied) to 5 (very satisfied/very good), and the score for each domain ranges from 4 to 20. The higher the score, the better the QoL. The WHOQOL-BREF has been used in two PD caregiver studies [30,31] . It showed significant differences between Brazilian PD patients and caregivers in two dimensions, and caregivers’ QoL was negatively associated with patients’ age; however, no further psychometric properties have been reported in PD caregivers [30] . The WHOQOL-BREF showed a total scale M ± SD value of 66.8 ± 11.9 in a sample of 60 PD caregivers [31] . Critical view

There are several QoL measures that have been successfully used in PD caregivers, and one of them, the Scale of Quality of Life of Caregivers, was specifically designed to measure the QoL of caregivers, and displays good psychometric properties in PD caregivers. Although all measures have been successfully validated in the general population, there is a lack of information about the psychometric properties of the instruments when applied to PD caregivers. Owing to the paucity of psychometric information www.expert-reviews.com

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specific to PD caregivers, the choice of a QoL instrument should be based on other criteria, such as the questionnaire length and the dimensions covered. Measures of caregiving burden

The concept of caregiver burden includes emotional impact, stress and responsibility for caring, modification of habits and routines, economic loss and costs, health problems and QoL deterioration. The three most commonly used measures of caregiver burden in PD are the Zarit Caregiver Burden Inventory [32] , the Caregiver Burden Inventory [33] and the Caregiver Strain Index [34] . Other scales used to measure caregiver burden in PD are the Subjective and Objective Burden Scale [35,36] , the Relatives’ Stress Scale [37,38] , the Family Caregiving Inventory [39–41] and the Burden Index of Caregivers [42] . Zarit Caregiver Burden Inventory

The Zarit Caregiver Burden Inventory rates the impact of the disease on the caregiver’s emotional, physical, and social and financial aspects [32] . Its 22 items are answered on a 0 (never) to 4 (nearly always) scale, and the higher the total score, the higher the burden. The Zarit Caregiver Burden Inventory was developed for use in caregivers of elderly or disabled persons and it allows for broader applications, including PD [3,6,10,42–47] . In a sample of 80 PD caregivers, this questionnaire showed acceptable data quality (90% computable scores and no floor or ceiling effect), Cronbach’s a of 0.93, moderate-to-high convergent validity (correlation coefficients) with number of caregiving hours, the caregiver’s mood and the patient’s clinical variables, and a significant relationship with PD stage [10] . Another study reported an internal consistency of 0.93 [44] . The Zarit Caregiver Burden Inventory was not sensitive to change from memantine treatment to the PD patient [47] . Across studies, this scale showed a mean value range of 14.9–35.0 (SD: 9.9–18.7) in PD c aregivers [6,10,42,43,45–47] . Caregiver Burden Inventory

The Caregiver Burden Inventory was developed as a diagnostic tool of professional caregivers’ feelings and responses to the demands of care [33] . It comprises 24 items, grouped into five subscales (time-dependency burden, developmental burden, physical burden, social burden and emotional burden). Items are rated into a 4-point scale, and higher scores reflect higher burden. This questionnaire has been used with informal caregivers of PD patients [21,48–50] . There is no information available about its psychometric properties in this specific group besides evidence of being sensitive to change after a cognitive–behavioral therapy intervention [48] . PD caregivers showed baseline M ± SD values of 54.5 ± 15.2 and 48.0 ± 17.9 for the treatment and control groups, respectively [48] . Caregiver Strain Index

The Caregiver Strain Index is a 13-item questionnaire that measures burden strain associated with care [34] . Major domains are employment, financial, physical, social and time considerations. 223

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The response format is yes/no, and higher scores indicate greater caregiver burden. There is a newer version, the Modified Caregiver Strain Index, with items answered on a 0–2 rating scale [51] . Although initially developed for post-hip surgery and heart disease patients over 65 years of age, the original version of the Caregiver Strain Index has been used in PD [24,28,48,52] . This instrument seems to be sensitive to change after treatment programs [28,48] . The range of mean values across studies is 3.0–8.7 (SD: 2.7–3.5) [24,28,48] . Critical view

Out of the measures of caregiver burden most commonly used in PD, only the Zarit Caregiver Burden Inventory has psychometric properties specifically assessed in PD caregivers, with good results. Both the Caregiver Burden Inventory and the Caregiver Strain Index show promising results regarding their sensitivity to change in studies with PD caregivers. Similarly to QoL, to the authors’ knowledge specific measures for the assessment of burden of caregivers for PD patients have not been developed. The importance of developing disease-specific measures is contro versial. On one hand, the use of a specific PD measure would help to capture particular aspects of PD-related burden, such as those related to on–off oscillations, social isolation or safety concerns [53] . On the other hand, caring for PD patients shares many common aspects with other neurodegenerative conditions and using more general measures allows comparisons between different conditions. The effect of PD on caregivers Factors related to QoL

Awareness of the factors contributing to decreased QoL in PD caregivers is important for developing strategies aimed at relieving the adverse effects of caregiving, and for supporting caregivers in their role, redounding in benefits for patients, caregivers and the healthcare system. In the last few years, an increasing number of studies have targeted this issue [7] , but the relationship between caregiver and patient features and their input in the caregiving process is of a complex nature. A number of factors related to PD caregivers’ HRQoL have been analyzed and the findings published [4,7,54] . For the purpose of clarity, a distinction can be made among sociodemographic, psychological and disease-related factors [7] and, on the other hand, between negative (stressors) and positive (protective) factors [4,54] . An important point to be taken into account is that most studies on caregivers’ QoL and burden are cross-sectional rather than longitudinal [7,55] , and this prevents the establishment of causality between factors and QoL and burden. A factor may be considered ‘determinant’ (or predictive) when it influences the QoL (or HRQoL) through a causal relationship, which is demonstrated by a consistent and constant relationship and by the change induced in the QoL when the factor is modified. To establish causality the factor must also precede or coincide with the consequences on QoL in time. On the other hand, an ‘associated’ factor will not show a tight and constant relationship 224

with QoL, which will not necessarily be modified after a change in the factor. In PD patients, depression, disability, fluctuations, insomnia, fatigue, pain, axial impairment/gait impairment and nonmotor symptoms as a whole have been identified as determinants of patients’ HRQoL [56,57] . For the individual patient, however, any symptom severe enough to reach a level dominating the patient’s day will be a determinant of HRQoL (e.g., tremor, urinary urgency, drooling, constipation, sweating and so on). Longitudinal studies on caregivers’ QoL and burden [55,58] give the opportunity to identify the effect that PD progression has on caregivers. Determinant and associated factors of QoL in care givers of persons with PD need specific consideration because the caring role eventually involves assistance to a close person with both physical and psychological impairments. Sociodemographic variables

Satisfaction with life, QoL and HRQoL are lower among PD caregivers than in the general population, and deteriorate significantly with increasing PD severity among patients [6,18,59,60] . Concerning basic epidemiological analyses, more anxiety and worse HRQoL were observed in female caregivers in one study [6] , but not in another that used different assessment methods [21] . Age of the caregivers has shown no, or marginal, relation with global QoL or HRQoL [6,18,21] . Psychological variables

Some psychological predictors of caregivers’ QoL have been identified. Both patient and caregiver depression impact on the caregivers’ QoL and HRQoL [6,10,21,59,61] . Depression is a consistent predictor of QoL in many different scenarios [62–64] and also in caregivers of patients with a progressive neurological disease [31] , but the relationship between patients’ mood disorders and caregivers’ distress and QoL deterioration is remarkable. An association has been found between depression in patients and depression in caregivers [6,21] . This finding may reflect the direct influence of the patient’s mood on the caregiver’s mood status, but also a potential indirect effect, because depression in patients correlates positively with disability [19,65] , which, in turn, deteriorates caregivers’ QoL. Other mental symptoms of patients, such as apathy, cognitive impairment, agitation, aberrant behavior and delusions, have been identified as consistent and powerful predictors of caregiver distress [21,59,61,66,67] and, therefore, as factors contributing to deterioration of caregivers’ QoL. In short, caregiver depression and patient mood, cognitive impairment and behavioral disorders have been demonstrated to affect the QoL of caregivers. Similarly, patients’ HRQoL (evaluated by patients themselves or by the caregivers) was a predictor of caregivers’ QoL and HRQoL [18,21,68] , a fact attributed to the impact that the patient’s condition, as perceived by the caregiver, exerts on emotional aspects of the latter. Social isolation and loneliness, related to caregiver variables such as education, perceived self-efficacy and physical health have been found to be related to caregivers’ QoL in different environments [69,70] . Expert Rev. Pharmacoecon. Outcomes Res. 12(2), (2012)


Disease-related variables

Several studies have found a relationship, as determinant or associated factors, between caregivers’ QoL/HRQoL and disease-related variables, such as disease severity and disability expressed in terms of motor and mental aspects [7,10,18,19,21,26,59] . Disease-related stress subsequent to care intensity and disease duration, and sleep disorders in the caregiver, induced or worsened by patients’ nocturnal troubles, are associated with QoL deterioration [26,50] . Intensity and duration of care can give rise to physical symptoms such as tiredness and fatigue, muscle strain and pain, hypertension and headache [26,60] . These symptoms and sleep disorders may interact with the mood disorder, closing a self-promoting circle of manifestations with the capacity to cause a severe decline in HRQoL.

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Financial pressure increases as disease progresses, owing to the increase in time and effort required for caregiving [72] , and these are important predictors of burden. Disease-related variables

Disease-related variables that have been demonstrated to affect the the caregiver’s burden are disability, PD severity and duration, motor impairment, motor complications, falls and non motor symptoms, such as autonomic dysfunction, pain, apathy, fatigue, cognitive impairment, hallucinations and sleep disorders [6,10,21,26,46,49,50] . Care intensity and the proportion of the day devoted to caring have shown a significant association with burden, although daily time spent in caring was not a predictor of burden after adjustment by other factors [10,50] .

Factors related to burden

Protective & negative factors

As previously mentioned, there is a conceptual distinction between caregivers’ QoL and burden [13] . As a matter of fact, they are affected by different factors and the relationship between burden and QoL or HRQoL is not a simple one [6,10,13,18,21] . In a cross-sectional study of 80 PD patients and their caregivers, the caregiver’s burden showed a close correlation with the SF-36 mental components and low-to-moderate correlations with SF-36 physical dimensions and EQ-5D index and VAS [10] .

Studies have found that some variables have a protective effect for caregivers’ health and QoL [4,54] . Among these, caregiver–patient relationship, perceived social support, frequency of breaks, formal service hours [4,13] and personality traits, such as self-esteem, preparedness and the ability to draw meaning from the care experience [54] , and mutuality and optimism [55] may shield or protect the caregiver against the negative outcomes of caregiving. A stress-appraisal model for caregivers’ QoL and burden, which includes the relationships between positive (or protective) and negative factors (those adversely affecting caregivers) and the role of variables acting as mediators (e.g., self-esteem), has been developed and tested [4,13] using structural equation modeling [4] and path analysis [13] , with results supporting the model. This model can help to identify which variables affect QoL and burden and to what degree, and to design appropriate and effective interventions, although further research is needed in order to confirm the results in PD caregivers.

Sociodemographic variables

Age of the caregivers has been shown to have an effect on strain (the younger the age, the worse the strain) [54] . Other socio demographic variables, such as gender or social status, have not shown a significant effect on the caregiver’s burden [6,21,26,43] . Psychological variables

In PD, several studies found a significant association between depression in patients and burden in caregivers [10,21,50] . However, as previously mentioned, depressed patients are more disabled and have more severe PD disease than nondepressed patients [19,65] , and this may result in higher needs of caring. In addition, depressed caregivers showed higher levels of burden than nondepressed caregivers, and depression in caregivers was the most powerful predictor of burden [6,10] . HRQoL of patients correlated significantly with their caregiver’s burden [6,21] . On the other hand, burden was related with psychological wellbeing in caregivers [6,10] , a finding that corroborates the previously discussed association between these constructs. Regarding the psychological factors, caregivers’ coping abilities and personality characteristics have been found to be important determinants of caregivers’ distress, influencing QoL and burden [3,7,54] . Perception of one’s own adequacy for coping with stressors impact on the caregiver’s burden, and personality traits such as optimism and pessimism play a key role in predicting caregivers’ health [23] . Other psychosocial factors identified as being relevant to the caregiver’s burden are: patient–caregiver relation ship and caregiver satisfaction with marital and sexual relationships [4,21,31,54] ; social support [53] ; and impact of the disease on the caregivers’ economic resources and opportunities [13,70,71] . www.expert-reviews.com

Economic costs

The great majority of PD caregivers are family members. Therefore, the economic burden of the disease will impact the patient as well as the patient’s direct family, which includes, most of the time, the caregiver. Research indicates that direct costs are higher for patients with motor fluctuations, patients with advanced PD stages and for institutionalized patients [5] . The major sources of cost for patients are inpatient care, longterm care and medications [73] . The major proportion of indirect costs, approximately 30–40% of total costs [73,74] , is the earnings lost by caregivers and patients, as well as the hours required for caregiving [75] . Work-related costs

Costs due to loss of work productivity in caregivers are difficult to assess because most studies compute this parameter for the patient and the caregiver together [76,77] . However, loss of income as a consequence of caregiving is frequent. In a UK survey of 1881 PD caregivers, 26.0% reported that they had to reduce or give up work, and 30.4% reported that their finances got worse owing to caregiving [78] . 225

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The cost of home care

A study including 49 PD patients from Portugal estimated that the cost of taking care of a PD patient for 8 ± 6 daily h was €56 (95% CI: 34–81) for a 6-month period in 2005 [77] . In Italy, home care provided by family members and friends was €2060 (95% CI: 1320–2860) per 6 months in 2009 [74] . In Russia, the cost of informal care was €620 (95% CI: 400–840) for a 6‑month period at 2008 values [79] . In a comparison of six European countries, the costs of home care ranged from €60 in Portugal to €1960 in Italy, for a 6-month period in 2008 [73] . The great variability of figures not only reflects differences between countries, but also methodological differences in cost calculations, such as inclusion and price of professional caregivers in at-home caring, loss of productivity at full wage rate or loss of leisure time. In summary, it is known that there is a strong relationship between the patient’s QoL and the cost of PD [80] . However, there is a lack of research on the costs of informal caregiving, and the costs of caregiver burden are usually not factored into cost–effectiveness analyses. More studies are needed to assess the impact of the PD cost on the caregiver’s QoL. Intervention programs for caregivers

The demands of caring for a person with PD require time, and physical and emotional resources that can lead to restrictions on several life areas, such as social, work and leisure activities. The negative impact of these factors on the physical and emotional health of caregivers implies a reduction of their QoL. The care givers may benefit from specific interventions aimed at reducing the burden and distress associated with caregiving and supporting caregivers in their role. Regular therapeutic strategies can help considerably. For example, a successful antidepressant treatment that was needed to control the mood disorder in the patient (or in the caregiver) might improve the caregiver’s QoL and decrease the burden [81] . Other interventions proposed for caregivers of PD patients may be grouped into the following categories: cognitive–behavioral therapy, psycho–educational therapy, support groups, rehabilitation, communication skills and respite care.

intervention that provides eight weekly sessions for groups of four to seven caregivers, with parallel sessions for patient groups, following cognitive–behavioral therapy principles [27] . Seven European countries participated in the study, with a total of 137 caregivers of PD patients; 75% of PD patients had mild disease (Hohen and Yarh stage 1–2). Results comparing pre- and post-intervention scores showed significantly lower caregiver burden and need for help in the Belastungsfragebogen Parkinson Angehörigenkurzversion (BELA-A-k) questionnaire [84] , improved mood ratings after sessions and a good satisfaction with the program. In a study of 111 caregivers, when compared with a waiting list, those participating in an intervention teaching coping skills showed lower depression and increased morale [85] . Support groups

Support groups are frequently incorporated as part of intervention packages. Group support delivered by web-based weekly video conferences is supported by one study with 34 family caregivers of persons with neurodegenerative diseases, including PD [86] . Results from qualitative analysis indicate perceived benefits in terms of physical and mental health, as well as stress and distress associated with caregiving. However, this study did not include a control group, nor did it compare pre- and post-intervention results. Rehabilitation programs

The rehabilitation programs that include a component directed to the caregiver were actually designed for treatment of PD patients. A small group of eight patients and seven caregivers participating in a 12-week Taiji program with 45-min classes perceived benefits in physical, psychological and social domains [25] . Outcomes were measured in terms of perceived benefits by participants and instructor observations, with no inclusion of a control group. In a 6-week, 1-day-per-week program providing intensive multi disciplinary rehabilitation for both the caregiver and patient (118 dyads), caregivers did not show statistically significant pre–post intervention improvement in standardized measures of depression and QoL, even though they reported knowledge gain and being satisfied with the program [29] .

Cognitive–behavioral therapy

Communication skills

Cognitive–behavioral therapy for PD caregivers was tested in a randomized clinical trial [48] . The participants comprised 30 caregivers who suffered from psychological distress according to the General Health Questionnaire (GHQ)-28 [82] . The study compared an intervention of 11–19 weekly individual sessions, with eight modules teaching adaptive coping strategies, with a notreatment control group. Caregivers were mostly women, who were spouses/partners of patients with moderate PD (Hohen and Yahr stage 2.5–3.0). After treatment and at 3‑month follow-up, significant improvement was observed in the Caregiver Stain Index [34] , Caregiver Burden Inventory [33] and GHQ-28 [82] .

Communication skills were included in some intervention programs. One study compared communication groups with support or mixed-format groups [87] . Twenty-two patient–caregiver dyads participated in the study. All but three caregivers were spouses, the time since PD onset ranged from 2 to 20 years, and PD severity was not rated. The groups met weekly for 6 weeks and the results indicate that communication ratings significantly improved in the intonation and body language measures for the communication and mixed-format groups, and that participants preferred the mixed-group format. Respite care

Educational programs

The educational component is included in most interventions for PD caregivers [83] . The EduPark is a psycho–educational 226

Although respite care is frequently offered to caregivers to allow them to attend to the intervention programs, the preference for different types of respite care was specifically evaluated in a Expert Rev. Pharmacoecon. Outcomes Res. 12(2), (2012)


heterogeneous sample of 168 caregivers [88] . Respondents showed a clear preference for in-home respite care. Critical view

It is very difficult to compare different types of interventions for PD caregivers for the following reasons: • Most intervention packages include multiple components, but the results are assessed in a global way; • Very few studies include a control group or random assignment of participants to treatment condition, and studies rarely followed a randomized clinical trial design [48,85,89] ; • The assessment is frequently based on the participants’ satisfaction ratings; • Since the majority of interventions are aimed at the caregiver and the patient simultaneously, it is hard to separate the benefits of one from the other. In fact, caregivers might improve in their QoL and burden measures simply owing to the improvement of the patients’ condition rather than the intervention; • Long-term follow-ups are needed to distinguish the effects of the natural course of the disease from the effects of other factors able to modulate the caregivers’ QoL and burden [83] . A meta-analytic study on interventions to support PD caregivers would be very pertinent to evaluate their relative efficacy. Conclusion

Most PD patients live in the community and are looked after by family members and other nonprofessional caregivers. The role of caregiver involves a whole range of obligations and duties, known as ‘caregiver burden’, whereas QoL reflects the impact of the disease on the caregivers’ lives from their perspective. Caregivers’ HRQoL refers to the consequences of the disease on the physical, psychological and psychosocial aspects of QoL. Using QoL and burden measures and through a diversity of methodological approaches, it is possible to quantify the caregiver’s status in terms of QoL and burden, identify predictors and determine outcomes of the interventions. Depression in patients and caregivers are the most consistent determinants of caregivers’ QoL. Furthermore, neuropsychiatric symptoms of patients (e.g., apathy and delusions), PD severity and duration, patients’ disabilities and HRQoL, care intensity and caregivers’ sleep disorders, social isolation and loneliness also contribute significantly to deterioration of caregivers’ QoL. Younger age of caregivers, depression in patients and caregivers, care intensity, PD severity and duration, patients’ disabilities, motor complications, falls and nonmotor symptoms (e.g., autonomic dysfunction, pain and fatigue) are predictors of caregiver burden. There is also an association between burden and patients’ HRQoL, caregivers’ coping abilities and personality characteristics, patient–caregiver relationship and mutuality, and economic problems. Conversely, a good caregiver–patient relationship and mutuality, perceived social support, frequent breaks, formal support www.expert-reviews.com

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service and positive personality traits (e.g., self-esteem) can exert a protective effect on caregivers’ QoL and burden. Nonprofessional caregiving buffers the costs of caring for health systems and, therefore, social and economic support to caregivers will help to maintain their QoL and decrease their burden, as well as to keep patients at home properly looked after. Finally, interventions aimed at improving the caregivers’ QoL and burden should be implemented to counteract the effect of negative factors causing distress and overwork. Some of the tested interventions seem to produce beneficial effects on physical, psychological and social aspects, but research on the efficacy of interventions aimed at PD caregivers is still in its early days. Expert commentary

There is increasing interest in the consequences that a chronic, disabling disease has on the persons around the patient. Likewise, a clear awareness exists of the importance that nonprofessional caregiving has for the patients and the society as a whole. For example, patient institutionalization is necessary when the ability of the caregiver to assist the patient is surpassed by the circumstances of caring, including physical, psychological, social and financial aspects, which are components of QoL and burden. However, the number of studies focused on caregivers of PD patients is still relatively small and these studies have been performed using nonspecific measures, many of them coming from research on caregivers of patients with dementia. There are some promising results concerning the effectiveness of interventions that assist PD caregivers. However, more research on interventions for caregivers is needed, especially studies that follow a randomized clinical trial design, with sample sizes large enough, that report effect sizes and identify potential moderators. Culture and social structuring condition the availability of resources and support, but existing data on the factors affecting the caregiver’s situation are restricted to a few countries. Therefore, more studies on the many facets of this field are needed. Five-year view

It seems quite logical to anticipate a growing number of studies on the caregivers of PD patients. These studies will put the focus on matters such as development of specific measures for caregivers’ QoL and burden, the effects on caregivers of nonmotor symptoms (specific and as a whole) and new therapies for patients, and unmet needs. New and specific support strategies for caregivers could probably be developed, applying a systematic approach to their circumstances based on the increasing knowledge about the determinant factors of QoL and burden. Financial & competing interests disclosure

The authors have no relevant affiliations of financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. No writing assistance was utilized in the production of this manuscript. 227

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Key issues • Caregivers of patients with Parkinson’s disease (PD) experience burden and diminished quality of life (QoL) as a result of the caregiving responsibilities. • There is a specific measure of QoL for caregivers, the Scale of Quality of Life of Caregivers, which has been used in several studies on PD. The rest of the commonly applied scales, both for QoL and burden, are generic and nonspecific. • Depression in patients and in caregivers is a powerful determinant of caregivers’ QoL and burden. In addition, neuropsychiatric symptoms in patients severely impact on caregivers. • PD severity and duration, disability and motor complications induce worse QoL and more strain on caregivers. • The loss of earnings by caregivers and the hours required in caregiving are major sources of costs for PD caregivers. • Intervention programs for PD caregivers are usually multicomponent, and may include cognitive–behavioral therapy, psycho–educational therapy, support groups or respite care. • The number of studies focused on QoL and burden of caregivers of PD patients is still relatively small and restricted to a few countries and cultures. description and analysis of the Scale of Quality of Life of Caregivers.

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