TABLE 2.
Analysis of narcotic calls for service in Baltimore, MD, from 2001 to 2010, using space-time statistics and adjusting for neighborhood economic deprivation and housing vacancy
| Cluster (region) | Years | No. of neighborhoods in cluster | No. of observed narcotic calls for service | No. of expected narcotic calls for service | Riska | Relative riskb | P valuec |
|---|---|---|---|---|---|---|---|
| 1. Most likely cluster (West) | 2005–2009 | 1 | 8,589 | 856.12 | 10.03 | 10.33 | <0.001 |
| 2. Secondary cluster (Northwest) | 2001–2010 | 5 | 18,038 | 8,009.17 | 2.25 | 2.34 | <0.001 |
| 3. Secondary cluster (Southeast) | 2001–2010 | 1 | 2,591 | 418.98 | 6.18 | 6.23 | <0.001 |
| 4. Secondary cluster: (West) | 2001–2010 | 39 | 93,677 | 77,622.42 | 1.21 | 1.32 | <0.001 |
| 5. Secondary cluster (West) | 2001–2010 | 2 | 4,333 | 2,056.38 | 2.11 | 2.13 | <0.001 |
| 6. Secondary cluster (Northeast) | 2001–2010 | 2 | 1,808 | 586.75 | 3.08 | 3.10 | <0.001 |
| 7. Secondary cluster (East) | 2001–2003 | 5 | 8,322 | 5,292.71 | 1.57 | 1.59 | <0.001 |
| 8. Secondary cluster (Northeast) | 2001–2004 | 1 | 292 | 41.58 | 7.02 | 7.03 | <0.001 |
| 9. Secondary cluster (Northeast) | 2009 | 1 | 351 | 92.54 | 3.79 | 3.80 | <0.001 |
| 10. Secondary cluster (Northeast) | 2007–2010 | 1 | 285 | 67.19 | 4.24 | 4.25 | <0.001 |
| 11. Secondary cluster (East) | 2002 | 3 | 1,550 | 1,168.35 | 1.33 | 1.33 | <0.001 |
| 12. Secondary cluster (East) | 2001 | 1 | 581 | 388.81 | 1.49 | 1.50 | <0.001 |
| 13. Secondary cluster (Northeast) | 2004–2006 | 1 | 334 | 204.47 | 1.63 | 1.63 | <0.001 |
| 14. Secondary cluster (North) | 2008–2010 | 1 | 105 | 50.49 | 2.08 | 2.08 | <0.001 |
| 15. Secondary cluster (Northeast) | 2003–2004 | 1 | 57 | 21.27 | 2.68 | 2.68 | <0.001 |
| 16. Secondary cluster (Northeast) | 2007–2009 | 1 | 214 | 133.56 | 1.60 | 1.60 | <0.001 |
| 17. Secondary cluster (North) | 2004–2007 | 1 | 104 | 52.89 | 1.97 | 1.97 | <0.001 |
| 18. Secondary cluster (North) | 2005–2009 | 3 | 715 | 563.56 | 1.27 | 1.27 | <0.001 |
| 19. Secondary cluster (Northeast) | 2002 | 1 | 63 | 31.25 | 2.02 | 2.02 | 0.022 |
Neighborhood economic deprivation was measured by an index constructed using the following eight items from the 2000 US census: percent of individuals employed in professional/managerial occupations (reverse coded), percent of households with crowding, percent of households living in poverty, percent of female-headed households with dependent children <18 years old, per households on public assistance, percent of households earning low income, percent of individuals with less than a high school education, percent of unemployed individuals >16 years old. Most likely, cluster defines the cluster with the highest maximum likelihood ratio
aRisk is the number of observed narcotic calls for service / number of expected narcotic calls for service in the cluster
bRelative risk is the ratio of risk inside cluster compared to risk outside cluster
cSignificance determined by Monte Carlo simulations