Table 3.
Age-and-sex adjusted prevalence and incidence rates* of type 2 diabetes mellitus (T2DM) by tertiles of neighborhood environments.
| Age-and sex-adjusted prevalence rates (%)* | ||||
|---|---|---|---|---|
| Neighborhood environments | Low | Medium | High | §P for trend |
| †Survey-based social environments | ||||
| Social cohesion | 22.4 | 21.6 | 18.9 | 0.017 |
| Violence | 19.1 | 20.0 | 23.8 | 0.002 |
| Problems | 18.6 | 20.8 | 23.4 | 0.001 |
| ‡GIS-based physical environments | ||||
| Favorable food stores | 19.4 | 21.6 | 22.9 | 0.011 |
| Unfavorable food stores | 17.9 | 23.0 | 21.9 | 0.010 |
| Physical activity resources | 19.3 | 21.9 | 21.8 | 0.089 |
| Age-and-sex-adjusted incidence rates per 1000 Person Years * |
||||
| Neighborhood environments | Low | Medium | High | §P for trend |
| †Survey-based social environments | ||||
| Social cohesion | 27. 5 | 24.8 | 20.8 | 0.010 |
| Violence | 21.6 | 26.4 | 25.0 | 0.187 |
| Problems | 23.1 | 23.1 | 26.6 | 0.190 |
| ‡GIS-based physical environments | ||||
| Favorable food stores | 21.7 | 24.5 | 28.2 | 0.008 |
| Unfavorable food stores | 21.1 | 23.8 | 28.4 | 0.007 |
| Physical activity resources | 21.6 | 25.2 | 26.0 | 0.086 |
Abbreviation: GIS: geographic information systems.
Logistic regression was used to estimate age-and sex-adjusted prevalence rates of T2DM and Poisson regression was used to estimate age-and sex-adjusted incidence rates of T2DM (sum of events/person-years) according to neighborhood scores; person-years were approximated by using midpoints between clinic visits.
Survey-based neighborhood environments were collected from JHS participants and aggregated to census tracts using empirical Bayes estimation. Item responses had a possible range of 1 to 4; higher scores indicate better social cohesion, and higher violence and problems.
GIS-based densities of favorable and unfavorable food stores and physical activity resources were derived using standard industrial classification codes from commercial listings of establishments obtained from National Establishment Time-Series database from Walls & Associates. The densities were calculated for a 1-mile buffer around each of JHS participant’s residential address.
P for trend for neighborhood scores entered as ordinal variables in logistic regression or Poisson model.