Table 2.

CCS estimates (population in thousands) and model fits for cities. Each CCS estimate is the X-intercept of a linear model of proportion zero observations (Pr₀) versus population size, excluding cities with no sampled zeros (see figure 3). Thus, each CCS estimate is the expected population size (total: CCS_T, effective: CCS_E) at which no zeros are observed. The longer two-week sampling period of E&W is expected to reduce Pr₀, and thus lower both measures of CCS, relative to the USA. WC, whooping cough.

disease	area	CCST [×103]	adj R2	CCSE [×103]	adj R2
measles	E&W	325	0.84	180	0.82
measles	USA	1678	0.63	417	0.89
WC	USA	952	0.37	71	0.90