Table 8.

Merged data from quantitative and qualitative research findings

Topic	Quantitative findings	Qualitative findings	Integrated findings
Relationships and social support	Informal caregivers that reported more perceived social support, reported a lower perceived caregiver burden	Informal caregivers experienced several challenges regarding the relationship with the person with PD that impacted the perceived caregiver burden. Several informal caregivers reported role-reversal, sense of loss of the relationship, feeling disconnected from person with PD and becoming more and more a carer than a partner. By contrast, others reported that PD has deepened the relationship with the person with PD and increased mutual understanding Informal caregivers also reported that PD also impacted their relationship with others. They felt confronted with incomprehension from their surroundings and also felt a lack of flexibility and independence to continue with their social life	Expansion: PD impacts the relationship between the informal caregiver and the person with PD, which can have negative as well as positive impact on perceived caregiver burden Confirmation: Social support has a positive impact on perceived caregiver burden
Coping strategies	Problem-focus and avoidant coping behaviour was associated with a higher perceived caregiver burden	Informal caregivers reported the use of emotional coping as well as problem-focused to be prepared for the future	Discordance: Problem-focused coping can have a positive as well as negative impact on perceived caregiver burden
Motor and non-motor symptoms	Informal caregivers reporting that the person with PD had higher motor impairments and higher impairments in activities of daily living and had a higher perceived caregiver burden	Informal caregivers reported that the burden of dealing with signs and symptoms of cognitive decline outsight the impact of motor symptoms. Cognitive decline put extra burden on informal caregivers through a higher dependence of the person with PD on support from the informal caregiver, including performing additional tasks. In addition, it was related to the fear of losing the person they were used to know, and the forgetfulness may lead to negative feelings such as sadness, anger and frustration	Expansion: Severity of motor symptoms and the related impairment of performing activities of daily living negatively impact perceived caregiver burden Informal caregivers reported that signs and symptoms of cognitive decline have a more severe impact on perceived caregiver burden
Concerns about the future	–	Informal caregiver indicated that they were confronted with both: (1) fear and worries of the person with PD, related to disease progression and severity of symptoms, and (2) own fears and worries about the future way of living and dealing with the impact of PD	Expansion: Concerns of the impact of PD on one’s own future as well as on the disease progression and coping of the person with PD negatively impacts perceived caregiver burden
Impact on everyday life	–	Informal caregivers reported perceived restrictions and limitations due to PD, which included a lack of freedom and a lack of autonomy due to a change in daily routines	Expansion: Lack of freedom and autonomy of informal caregivers negatively impacts perceived caregiver burden
Psychological and emotional well-being	No association was found for the impact of feelings of anxiety and symptoms of depression of the person with PD on perceived caregiver burden	Informal caregivers worried about the disease progression, as well as the concern to not be able to leave the person with PD home alone. In addition, informal caregivers reported a feeling of sadness as they experience a sense of losing the relationship, feeling to live a different life and the need to give up social and family life. Moreover, informal caregivers reported feeling guilty when they felt unable to deal with cognitive and behavioural impairments	Expansion: Informal caregivers’ emotion and psychological well-being impact perceived caregiver burden
Positive impact of PD	-	Informal caregivers reported that PD also had a positive impact on their life and relationship. They experienced more calmness due to living a more structured life and a stronger relationship with the person with PD	Expansion: PD has not only a negative impact on the life and relationship of informal caregivers, which positively impacts the caregiver burden