Chapter 17: Physical Activity Epidemiology Research SFM 651: Research Methods Dr. Johnson

Why Quantifying the magnitude of health problems Identifying factors that cause disease Providing quantitative guidance for the allocation of public health resources Monitoring the effectiveness of prevention strategies

Epidemiology The study of the distribution and determinants of health related states or events in specific populations, and the application of this study to the control of health problems Distribution = Frequency and patterns Determinant = any factor that brings about change

Measures Frequency – number of times per week Duration – time spent in activity Intensity – difficulty of the activity Dose – combination of all 3

types Questionnaires Interviews Equipment Accelerometers Heart rate monitor pedometers

Designs Descriptive Cross sectional Ecological Relationship of basic characteristics Age Sex Occupation Cross sectional Take people at different points Ecological Use existing data from the past

Designs Analytical Cohort Case-control Casual links between exposure and mortality Cohort Follow up studies – over time Case-control Some have disease, some dont

Bias Systemic deviation of a calculated value from the true value Changes in what the data actually say Interviews Observations etc