Factors

Number of studies

Key insights

Demographic variables

Gender

15

Patient and caregiver sex has little effect on caregiver burden, although there is a trend that higher burden scores are associated with female caregivers and male patients

Relationship

7

There is conflicting evidence as to whether spouses are more burdened than non-spouses. Spouses and non-spouses tend to differ with respect to the burden domains affected

Age

20

The influence of patient and caregiver age on caregiver burden emerged when comparing various caregiver age groups

Socio-demographic

5

Two studies reported cultural variation in caregiver burden

Motor symptoms of patients

PD stage

20

PD stage is an important predictor of caregiver burden

Parkinsonism

18

Many studies report on the relationship between caregiver burden and the motor severity of PD. Motor severity (apart from disability) is not reported to independently contribute to caregiver burden. Patient functional ability as assessed by several ADL scales correlates with caregiver burden. Evidence of the individual effect of functional impairment on caregiver burden is inconclusive

Falls and motor complications

8

Studies reporting on the relationship between caregiver burden and patient motor fluctuations, involuntary movements and falls confirm the association

Duration of PD

11

Most studies analysing the relationship between duration of PD and burden report a positive correlation

Non-motor symptoms

Depression

13

Depressive symptoms in patients are important contributors to caregiver burden

Anxiety and

apathy

5

The relationship between patient anxiety, apathy and caregiver burden is confirmed in a few studies

Cognition

9

Patients’ mild as well as serious cognitive impairment identified on several generic scales was related to caregiver burden

Psychotic symptoms and behavioural

disturbances

10

A few studies report on the association between patient psychiatric symptoms and caregiver burden. Patient behavioural problems as assessed by a variety of scales have been found to have a significant effect on caregiver burden

Neuropsychiatric comorbidity

6

In general, neuropsychiatric symptoms have a stronger impact on caregiver burden than motorsymptoms. Caregivers of patients diagnosed with comorbidities such as depression, apathy, dementia, psychosis and impulse control disorders reported more burden than caregivers of patients without such comorbidities

Other non-motor

symptoms

6

With the exception of neuropsychiatrics, non-motor symptoms are sparsely addressed. Sleep disturbance is reported as an independent contributor to caregiver burden

Patient’s Quality of life

9

Several studies demonstrate the association between higher burden scores and decrease in patient quality of life (QoL) as assessed by both PD specific and generic QoL instruments