Submitted by:

1. Spatial Distribution Patterns of Healthcare Coverage, Influenza-Pneumonia Vaccinations and Prevention of Hospitalizations in the District of Columbia, 2005 - 2009District of Columbia Submitted by: George N.F. Siaway, PhD, John O. Davies-Cole, PhD, MPH, Fern Johnson-Clarke, PhD, and Gerald Lucas, MS D.C. Department of Health November 2011

2. Abstract Introduction: The District of Columbia has consistently had less than optimal coverage of the Influenza-Pneumonia vaccine among residents 65 years or older. This is well below the year 2010 goal of “increasing to 90% the number of non-institutionalized adults aged 65 years and older immunized against Influenza-Pneumonia. It is estimated that more than 6000 deaths in the US that occur each year are due to pneumococcus infection. Yet, in 2007, only 55% of District residents, 65 years and older indicated they had a Influenza-Pneumonia vaccination in their lifetime. Objectives: Evaluate the effect of socioeconomic conditions and Influenza-Pneumonia vaccine coverage in reducing hospitalizations. and identify areas of the District which contribute significantly to the burden of Influenza-Pneumonia. Method: The Behavioral Risk Factor Surveillance System (BRFSS) data for year 2005-2009 and Hospital admissions and deaths for Influenza-Pneumonia were geocoded and analyzed for this study using ArcGIS 9.3 and the spatial statistics tools. Results: Though preliminary results showed high Influenza-Pneumonia hospitalizations in areas with high vaccine coverage, in in other areas, hospitalizations for Influenza-Pneumonia appear to decrease with high vaccine coverage. Conclusions: Though high vaccine coverage is associated with low hospitalizations in the District of Columbia, high vaccine coverage was associated with high hospitalizations in other areas. Therefore, targeted interventions should consider other socioeconomic factors that are intrinsic to those areas with the heaviest disease burden.

3. Background: Influenza-Pneumonia - Important Public Health Problem Some studies have explored the issue of influenza as an important public health problem and that influenza vaccination is important for elderly individuals with or without underlying chronic conditions (De Andres et al., 2007;Chowell et al., 2006). Others have identified distinct barriers to influenza vaccination that exist among racial/ethnic groups (Chen et al., 2007), and examined influenza vaccination rates and correlates of intention to be vaccinated among adults (Mok et al., 2006). The socioeconomic and health variables of population sectors that are less likely to be vaccinated include living in a densely populated house, being unmarried and heavy smoking (Sharabani and Benzion, 2006). Sharabani and Benzion (2006) found that chronic illness, previous hospitalizations, and older age tend to have a positive effect on the decision to take the flu vaccine. Xakellis (2005), for example,suggests that the major predictor of getting a flu shot in future years is having received one in the current year. Racial and ethnic disparities have been shown in the uptake and location of vaccination and seasonal Influenza (Uscher-Pines et al., 2011).

4. Discussion Results: Figure 1 shows the spatial distribution of flu shots by Wards . The distribution pattern of Influenza-Pneumonia vaccination-Age 65+, crude death rates, expected charges and hospital discharges are shown in Figures 2 - 3. Figures 4 – 6 show cluster analyses of hospital discharges, Influenza-Pneumonia vaccination of the 65+ age group, crude death rates and expected charges. Crude death rates, hospital discharges expected charges and vaccinations are shown in Figures 7 and 8. Figures 9A – 9B show distributions of whites and blacks in association with Influenza-Pneumonia crude deaths and hospital discharges. Though preliminary results showed high Influenza-Pneumonia hospitalizations in areas with high vaccine coverage in some parts of the District, in other areas, hospitalizations for pneumonia appear to decrease with high vaccine coverage. Zip codes in the north east – southeast consistently show high expected charges, discharges, deaths, and low vaccination rates for Influenza-Pneumonia. One zip code in Ward 8 showed low Influenza-Pneumonia crude deaths, low hospital discharges and expected charges, and high vaccinations. The highest flu vaccination rates were found in Ward 2, 4, 5, 6, 7 and 8 zip codes at 35.8% - 37%. High expected charges were found in Ward 1, 4, 5, 7 and 8 at $3,926,946.82 - $6,614,529.37. High discharges were found in Ward 1, 3, 4, 5, 6, 7 and 8 zip codes at 8.7% - 14.3%. High crude deaths were found in ward 2, 4, and 5 zip codes at 37.4% - 41.5%.

5. Figure1: Spatial Distribution of Influenza-Pneumonia Vaccination, 2008

6. Figure 2: Spatial Distribution of Influenza-Pneumonia Vaccination-Age 65+, Crude Death Rates and Hospital Discharges, 2008

7. Figure 3: Distribution of Influenza-Pneumonia Hospital Discharges and Expected Charges by Zip Code of Residence, 2008

8. Figure 4: Cluster Analysis of Influenza-Pneumonia Hospital Discharges, 2008

9. Figure 5A: Cluster Analysis of Influenza-Pneumonia Vaccination-Age 65+, 2008

10. Figure 5B: Cluster Analysis of Influenza-Pneumonia Crude Death Rates, 2008

11. Figure 6: Cluster Analysis of Influenza-Pneumonia Hospital Discharge Expected Charges, 2008

12. Figure 7: Crude Death Rates and Influenza-Pneumonia Hospital Discharges by Zip Code of Residence, 2008

13. Figure 8: Crude Death Rates, Hospital Discharges, Expected Charges and Vaccination – Influenza-Pneumonia, 2008

14. Figure 9A: Distribution of Crude Death Rates, Hospital Discharges and Whites by Zip Code of Residence – Influenza-Pneumonia, 2008

15. Figure 9B: Distribution of Crude Death Rates, Hospital Discharges and Blacks by Zip Code of Residence – Influenza-Pneumonia, 2008

16. Limitations of the Study This study data was not analyzed at the census block level. Analysis at the census block level would aid in a targeted approach to enhancing Influenza-Pneumonia vaccine coverage. Complete records for year 2008 hospital discharges, expected charges, crude deaths and Influenza-Pneumonia vaccination data was used in this study. Availability of complete data for current years would provide a better understanding of association between the spatial distribution of Influenza-Pneumonia vaccination, discharges, expected charges and deaths. BRFSS 2008 Influenza data was used as a surrogate for Influenza-Pneumonia since the spatial distribution pattern and trend of Influenza is consistent with that of Pneumonia. The BRFSS relies on information reported directly by the respondent. As such, this self-reported data may be subject to errors. The manner in which questions are worded and the ability of individuals to recall details may result in inaccuracies.

17. Conclusions Some zip codes in Wards 2, 6 and 8 consistently show low Influenza-Pneumonia crude death rates, hospital discharges and expected charges. The presence of health care facilities does not seem to affect Influenza-Pneumonia vaccinations, hospital discharges, expected charges and deaths. Though high vaccine coverage is associated with low hospitalizations in the District of Columbia, high vaccine coverage was associated with high hospitalizations in other areas. Therefore, targeted interventions should consider other socioeconomic factors that are intrinsic to those areas with the heaviest disease burden. The 65+ age group is associated with high vaccinations, high hospital discharges and high crude death rates. Zip codes in Ward 2 and 8 show the lowest Influenza-Pneumonia hospital discharge rates. Some zip codes in Wards 2, 3, 4 and 6 have high, similar and statistically significant clusters of Influenza-Pneumonia deaths (p = 0.01). One zip code in Ward 8 shows the lowest clusters of expected charges.

18. Lessons Learned Zip codes in the north east – southeast consistently show high expected charges, discharges, deaths, and low vaccination rates for Influenza-Pneumonia. One zip code in Ward 8 consistently had high Influenza-Pneumonia vaccination, low deaths, hospital discharges and expected charges. Results of racial disparity in this study is consistent with other findings in which whites were significantly more likely than blacks to receive a 2009-H1N1 vaccination (Uscher-Pines et al., 2011).

19. Selected References • Chowell G, Ammon CE, Hengartner NW, Hyman JM. Estimation of the reproductive number of the Spanish flu epidemic in Geneva, Switzerland. Vaccine. Nov 10 2006;24(44-46):6747-6750. • Chen JY, Fox SA, Cantrell CH, Stockdale SE, Kagawa-Singer M. Health disparities and prevention: racial/ethnic barriers to flu vaccinations. J Community Health. Feb 2007;32(1):5-20. • de Andres AL, Garrido PC, Hernandez-Barrera V, Del Pozo SV, de Miguel AG, Jimenez-Garcia R. Influenza vaccination among the elderly Spanish population: trend from 1993 to 2003 and vaccination-related factors. Eur J Public Health. Jun 2007;17(3):272-277. • Lori,U-P, Maurer, J., and Harris, KM. Racial and Ethnic Disparities in Uptake and Location of vaccination for 2009 – H1N1 and Seasonal Influenza. Am J Public Health. July 2011;101(7):1252-1255. • Mok E, Yeung SH, Chan MF. Prevalence of influenza vaccination and correlates of intention to be vaccinated among Hong Kong Chinese. Public Health Nurs. Nov-Dec 2006;23(6):506-515. • Shahrabani S, Benzion U. The effects of socioeconomic factors on the decision to be vaccinated: the case of flu shot vaccination. Isr Med Assoc J. Sep 2006;8(9):630-634. • Xakellis GC. Predictors of influenza immunization in persons over age 65. J Am Board Fam Pract. Sep-Oct 2005;18(5):426-433. • Zimmerman RK, Nowalk MP, Raymund M, et al. Tailored interventions to increase influenza vaccination in neighborhood health centers serving the disadvantaged. Am J Public Health. Oct 2003;93(10):1699-1705. • Uscher-Pines, L, Maurer, J and Harris, KM. Racial and Ethnic Disparities in Uptake and Location of Vaccination for 2009-H1N1 and Seasonal Influenza. Am J Public Health. July 2011; 101 (7):1252-1255.