Fig. 7

Ontological representation of a clinical study. This use case study analyzed the effects of variable levels of nurse staffing on inpatient mortality [22]. The data was obtained from eMedical records and then transformed. Cox proportional hazards model estimation (a type of survival analysis) was performed to identify the effect of hospital unit shift rates (independent variable) on the patient mortality rate (dependent variable). A p-value of <0.01 was used to draw a conclusion of the statistical significance between these two variables