Association between intervention effectiveness and the degree of spatial clustering of interventions by coverage level.

Association between intervention effectiveness and the degree of spatial clustering of interventions by coverage levels. β1 is an estimate (gradient) of the effect of the degree of spatial clustering of an intervention and β0 is an intercept measuring the effectiveness of the intervention at zero clustering. The higher β0, the higher the effectiveness at zero clustering. Figures in parenthesis are standard errors.aβ0 = ln (), where p0 is the actual effectiveness.bPositive relationship, implying a benefit of clustering the intervention.cNot statistically significant (i.e. p-value >0.05).