While summarizing our data in a table was useful, displaying it as a bar graph helped us more easily see that the majority of cases occurred among infants < 6 months of age. To get a more accurate picture of disease occurrence, we also looked at disease incidence by age group. This allowed us to make comparisons between age groups taking into account the fact that the age groups from which the cases derived came from different proportions of the total population within our community of interest. This analysis was a little more time consuming because it required us to know the size of the populations for each age group; however, this information was obtained from local vital statistics or census agencies. Examination of disease incidence by age group revealed that although the percent of cases in each of the three oldest age groups was higher than those for children 13-18 and 19-23 months of age, the actual incidence of disease was higher in the latter two age groups. Thus, when making decisions about where to target efforts for reducing pertussis disease, we know that attention should be given to pre-school children foremost followed by school-aged children, then adults.