Chronic Obstructive Pulmonary Disease (COPD) is one of the most common chronic respiratory diseases. COPD is a global burden that induces many decision-making problems. Medical decisions are naturally originated from personal experience of the physician and statistical analysis of previous data. Because of its structural advantages in revealing the behavior of complex systems, and in capturing human judgment by means of fuzzy information, Fuzzy Cognitive Map (FCM) and its extensions are widely used in medical decisions. In this paper, a novel approach called Statistical-Based Fuzzy Cognitive Map (SBFCM) is proposed which aggregates the power of statistical analysis with dynamical nature FCMs. The SBFCM method is developed in order to evaluate the factors that affect the length of hospital stay (LoS) of COPD patients that apply to the hospital with an acute exacerbation. Fifty factors, including LoS, are adopted as system concepts and observed under four groups. A real-case application is conducted and different scenarios are analyzed for a better understanding of the system behavior.