ABSTRACT
INTRODUCTION Epidemiology is the study of the distribution and determinants of health-related states or events in specifi ed populations, and the application of this study to control health problems (1). The ultimate goal of epidemiologic research of Parkinson’s disease (PD) is to fi nd the cause and prevent the occurrence of PD. This chapter focuses on describing the frequency, survival, and coexisting conditions of PD. We only briefl y discuss the etiologic aspects of epidemiologic studies, because genetic and environmental risk factors are detailed in other chapters in this volume.
