Table 2. Rotavirus Gastroenteritis IRR Among Infants in High Vaccination Coverage Districts (≥8.36%) Compared With Low Coverage (<8.36%) During the Prior 12 Months Among Children Aged 0 to 3 Years Old, 2007 to 2015 Seasonsa,b,c.
| Characteristic | IRR (95% CI) | P Value |
|---|---|---|
| Age, y | ||
| 0 | 0.673 (0.647-0.699) | <.001 |
| 1 | 0.694 (0.667-0.722) | <.001 |
| 2-3 | 0.640 (0.600-0.683) | <.001 |
| Period | ||
| 2007-2010 | 1.093 (1.001-1.190) | .05 |
| 2011-2012 | 0.64 (0.491-0.830) | .001 |
| 2013-2015 | 0.33 (0.308-0.350) | <.001 |
| Sex | ||
| Male | 0.679 (0.658-0.700) | <.001 |
| Female | 0.673 (0.646-0.702) | <.001 |
| Districtd | ||
| Rural | 0.826 (0.749-0.910) | <.001 |
| Urban | 0.728 (0.709-0.747) | <.001 |
| Total | 0.676 (0.659-0.693) | <.001 |
Abbreviation: IRR, incidence rate ratio.
The median (8.36%) of vaccination coverage during the prior 12 months was used as the cut-off point to classify high and low vaccination coverage. Regressions were fitted to quantify the association between monthly citywide vaccination coverage and monthly counts of patients with rotavirus gastroenteritis.
Secular trends, variation for laboratory confirmation, population density, Engels coefficient, per capita public green areas, and the meteorological factors including the minimum temperature, relative humidity, atmospheric pressure, and duration of sunshine were controlled in the models. Each Poisson model was fitted separately for age group, period, sex, and district. Population size was accounted for in the models as an offset.
Models were fitted separately by sex, period, age group, and district (rural or urban).
The IRRs for residence district were evaluated based on the district (rural or urban), vaccination coverage, and population density.