You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Epidemiology is primarily concerned with the: and explain in detail?
Epidemiology: 
Epidemiology is defined as the study of the distribution and determinants of health related states or events in specified populations, and the application of this study to the control of health problems. - John M. Last
Soben Peter 
Essentials of preventive and community dentistry 
4th edition