This study provides evidence for the reliability and validity of the ERM, a 9-item instrument that measures expectations among older adults regarding movement. It provides weaker evidence for the scale measuring healthcare seeking beliefs for parkinsonism, which had excellent internal consistency but did not meet our standards for construct validity. The use of the ERM instrument in subsequent research studies may help to explain the role of older adults' expectations in contributing to the diagnostic gap in PD, particularly among African-Americans.
Among our sample of community-dwelling older adults, the ERM scale demonstrated excellent internal consistency and good validity. Factor analysis showed that the constructs of Expectations Regarding Aging and Expectations Regarding Movement were closely related to each other, but measured different constructs. While the ERM measures expectations regarding the development of parkinsonism with aging, the ERA measures constructs related to cognitive, mental and general physical health (e.g. energy, pain).
The construct of movement-related expectations was further validated when scores on the ERM scale were compared by race. The finding that African Americans were more likely than whites to expect to develop parkinsonism informs prior findings regarding the relationship between race and PD. African Americans are less likely to receive a diagnosis of PD than whites 
. This suggests that the lower rates of PD diagnosis in African Americans may be related to lower expectations about movement.
Further validating the construct of expectations about movement were the associations seen with age, education and health status. Old age has previously been shown to correlate with attributing symptoms of disability to age itself 
. Educational attainment likely relates to health knowledge which in turn affects expectations. Lastly, those individuals with worse health status were more likely to have lower expectations. This finding corresponds with earlier reports that the standard by which individuals rate health is dependent on their own health 
This study provided some evidence for the construct validity of the instrument developed to measure healthcare seeking beliefs for parkinsonism (HSB). It is possible that this 9-item instrument only captured a portion of what motivates health behavior. Published health belief models include expectations about aging or perceived severity as one factor that influences health behavior 
; there are many other factors in the health belief model such as perceived susceptibility, perceived benefits (knowledge of treatment availability), perceived barriers (material and psychological costs), cues to action and self-efficacy that are important to measure to gain a complete understanding of what motivates healthcare seeking. Subsequent measures of healthcare seeking beliefs for parkinsonism should incorporate these other domains to adequately assess this construct.
This study had the following limitations. First, there is no gold standard test to measure expectations about movement. Therefore, we could not test criterion validity. Second, we also were not able to assess for test-retest reliability given the constraints of anonymous testing. Future longitudinal studies can assess both test-retest reliability and correlate ERM scores with health service use and health outcomes to further support score validity. Third, the use of a convenience sample may have introduced some sampling bias in the study responses. The predominantly women sample who attend senior centers may represent more active and health-conscious members of the community. This will limit the generalizability of the results.
Despite these limitations, this study is an important first step in developing an instrument that measures expectations about movement. Information collected through measures of aging expectations in general has been instrumental in developing targeted interventions to improve health in other areas of aging. Studies have shown that older adults with low expectations about physical activity and depression are less likely to seek healthcare 
. These findings have led to interventions to improve expectations and, in turn, health outcomes 
Based on our results, measuring expectations about movement may be an important first step in identifying individuals at-risk for the under-identification of PD. After identifying sub-groups of older adults that are at highest risk for low expectations and subsequent healthcare seeking, targeted interventions based on improving expectations can be implemented.