Predisposing factors are characteristics or conditions that make an individual more susceptible to a certain outcome. Enabling factors are resources or support systems that facilitate the desired outcome. Need factors are the actual requirements or demands that must be met for the desired outcome to be achieved.
For example, in the context of healthcare, a predisposing factor for developing heart disease could be a family history of the condition. An enabling factor could be having access to affordable healthcare services, while a need factor could be the need for medication and lifestyle changes to manage the condition.
Unfortunately, I cannot provide citations as I don't have access to external sources. However, you can refer to reputable medical or sociological journals for more in-depth information on these factors.
Regarding the aging population's impact on the U.S workforce, it poses challenges such as a shrinking labor force, increased healthcare costs, and a strain on social security systems. This is due to a larger number of retirees compared to the number of younger workers entering the workforce.