Time series data in epidemiology typically consist of four main components: 1. Trend: The long-term movement in the data, indicating an overall increase or decrease in disease incidence. 2. Seasonality: Regular, periodic fluctuations in the data due to seasonal factors. 3. Cycles: Long-term oscillations or waves in the data that are not of fixed period. 4. Irregularities: Random, unpredictable variations in the data that cannot be attributed to trend, seasonality, or cycles.
