Figure 1.

Reductionist versus systems research approach.

In the reductionist view, the system’s behavior (outcome measure-CVD) is explained by the selected components (e.g., hypertension and frailty). A research question: is hypertension alone or hypertension in combination with frailty, a better predictor of CVD? In the systems view, the system’s behavior (outcome measure-CVD) is the result of the interactions between a multitude of components. A research question: which of the factors associated with hypertension and frailty (e.g., the body mass index category; the age category; the degree of decline in kidney function; the level of blood pressure) impact the association of the coexistence of hypertension and frailty with CVD? CV: cardiovascular; CVD: cardiovascular disease.