Volume 11, Number 11—November 2005
Research
Rift Valley Fever in Small Ruminants, Senegal, 2003
Table 6
Parameters of the intercept-only and the best BIC mixed-effect binomial model of Rift Valley fever serologic incidence in small ruminants, Barkedji area, Senegal, 2003 rainy season*
Term | Parameter | Standard error | Z* | p† |
---|---|---|---|---|
Intercept-only mixed-effect model | ||||
Intercept | –3.49 | 0.58 | –5.99 | 2.1 × 10–9 |
Variance of the random effect‡ | 1.75 | – | – | – |
Best mixed-effect model according to information criteria | ||||
Intercept | –1.62 | 0.67 | –2.41 | 0.02 |
Surface§ | –0.19 | 0.09 | –2.08 | 0.04 |
Ferlo¶ | –1.95 | 0.88 | –2.21 | 0.03 |
Variance of the random effect‡ | 0.57 | – | – | – |
*Ratio of the parameter over its standard error. N = 610 small ruminants; BIC, Bayesian information criterion.
†P(x > |Z|) assuming a standard-normal distribution for Z; straight vertical bars indicate absolute value of Z.
‡Pond-related random effect associated with the intercept.
§Surface (hectare) centered on the smallest observed surface (1.6 hectare).
¶Location of the pond: in the Ferlo bed (reference category) or outside Ferlo bed.