Figure 2
From: Real time spatial cluster detection using interpoint distances among precise patient locations
Baseline distribution of respiratory patients to the emergency department of one hospital. The study population (blue dots) lived within 80 km of the hospital (black ring). Simulated clusters were placed at 5, 15, and 50 km, along the red rings. Total population density of study patients within the four areas pictured was: 182.6 per square km within 0–5 km of the hospital, 32.6 per sq km within 5–15 km, 1.3 per sq km within 15–50 km, and 0.1 per sq km within 50–80 km.