Volume 8, Number 7—July 2002
Time-Space Clustering of Human Brucellosis, California, 1973–1992 1
|Yearsa||No. of cases||z-scorec||p value||z-scorec||p value||z-scorec||p value|
aCases summed over the specified 5-year period. Incidence over the 20-year period is the mean of incidences for the 5-year periods.
bIncidences are based on the population of the 5-year period’s median year as the denominator. Incidences were adjusted by the direct method with the population distribution of Sacramento County in 1990 as the standard. Data for race were adjusted by using Hispanic and non-Hispanic population totals.
cPositive z-score indicates tendency towards clustering, negative value dispersion.
1 Preliminary results of this study were presented at the 9th Symposium of the International Society for Veterinary Epidemiology and Economics, August 6–11, 2000, Breckenridge, Colorado, USA.