Policy and Complex Systems
the model for the general level of dementia . Older agents needing care are paired with a caregiver agent . The status of an older adult needing care provides input to the decision making concerning the source of the needed care .
Agents Representing Caregivers
Caregivers are also represented as agents in the system because the focus of this model is the stress on caregivers . Caregiver agents have characteristics describing their capabilities and motivation . Their motivation is keyed to their relationship to the older adult , level of difficulty associated with caregiving , and their own needs .
Caregivers are modeled as having a current level of caregiving capacity and a current caregiving load , which is increased by additional stressors ( such as an increase in the needs of their frail older adult ) by assistance using a systems dynamics model . At each step , an evaluation of the caregiver ’ s previous stress level increases due to changes in the status of the associated care receiver , other stressors , and may be reduced by support systems .
We modeled a change in needed care as an additional stressor for one step ( a modeled year ). If the level of stress becomes too high ( i . e ., above the caregiver ’ s capacity ), a decision is made to change the arrangement for the assistance the associated older adult needs . Changes in caregiving arrangements can include various coping mechanisms for the caregiver , including changing who provides the needed care .
A Summary of Modeling Presumptions
Every tool used to evaluate policy options presumes its appropriateness to the task . A hammer is appropriate for driving nails and , although it can drive screws , there is a better tool for that purpose . We begin with the presumption of appropriateness of our tool and then explicitly describe the key modeling bases :
1 . Our model ’ s level of analysis , 100 older adults and their caregivers with a time step of a year is appropriate to explore the impact of adult daycare on caregiver stress .
2 . The health of older adults can be reasonably represented by the number of activities of daily life ( ADLs ) they cannot perform and four levels of dementia .
3 . The decline in the physical health of older adults is similar to data on the survivability of Americans by age .
4 . The stress felt by a caregiver is directly related to the number of ADLs their older adult cannot perform plus their level of dementia and is proportional to the average number of hours per week the caregiver is caring for the older adult .
5 . A simulation exploring different caregiving conditions using an ABM can provide insights into the policy options for addressing caregiver stress .
There are , of course , additional presumptions or approximations used in the model and they are discussed in the ODD + D .
Model Operation
The model begins with an initialization of the starting population of older adults and caregivers . Then , for each step , every agent becomes a year older and several other changes could occur . The physical and mental health of each older adult may degrade . The stress of each caregiving agent is re-evaluated and arrangements for the associated older adult could change . Each agent may also die . New older adults and caregivers are added to the simulation
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