Reduction in Mortality Associated with Influenza and Pneumococcal

Vaccination of Nursing Home Residents

Sophia Kazakova1, Dale Bratzler2, Wato Nsa2, Amy Curtis1 Linda McKibben1, Abigail Shefer1, Lynn Steele1,

Chesley Richards1, John Jernigan1

Centers for Disease Control and Prevention1

Oklahoma Foundation of Medical Quality2

Background• In the US 1.6 million residents live in more

than 17,000 long term care facilities (LTCF)

• Incidence of invasive pneumococcal disease 4 times higher among LTCF residents compared to older adults in the community1

• 90% of influenza related deaths in the US occur among the elderly2

1Kupronis et.al. J Am Geriatr Soc 2003;51:1520-1525.

2Thompson et. Al. JAMA 2003;289:179

Documented Influenza and Pneumococcal Vaccination Among US Nursing Home Residents, 1995-1999

63

24

64

28

66

38

0

20

40

60

80

100

Influenza Pneumococcal

1995

1997

1999

Healthy People 2010 Goal

Buikema AR, Singleton JA, et al. [abstract] Centers for Disease Control and Prevention, 35th National Immunization Conference.

% V

acci

nate

d

Vaccine Efficacy Among ElderlyVaccine Efficacy Among Elderly

• General and LTCF elderly populations– Influenza1

• Reduces respiratory illness, pneumonia and death

– Pneumococcal vaccine2

• Small sample size• unable to examine facility-level

characteristics

1Gross PA, et al. Ann Int Med 1995;123:518-5272 Jackson LA, et al. N Engl J Med 2003;348:1747-55, 2003

Study Objective

• To examine the impact of individual influenza and pneumococcal vaccination of Nursing Home residents on individual mortality controlling for individual and facility-level characteristics

The Immunization Standing Orders ProjectCenters for Disease Control and Prevention and

Center for Medicare and Medicaid Services

DC

14 States

Methods

Study Population– 20 LTCF within each state

• Size, influenza program type, and QIO participation

– 100 residents randomly sampled from each facility • November 2000 – January 2001• November 2001 – January 2002

Data Sources– Medical record review

• Influenza (October – December of the study year)• Pneumococcal vaccination status (life-time history)

– Minimum Data Set (MDS)• Coexisting conditions, Activities of Daily Living

– Medicare Claims and Enrollment Database • Vital status and demographics

Methods (continued)• Outcome

– Individual Vital Status (dead/alive) 14 days or more after flu vaccination during influenza season (November – April)

• Predictor Variables– Individual influenza and pneumococcal

vaccination

• Control Variables– Age, sex, race/ethnicity, diabetes, COPD, stroke,

cancer, renal failure, atherosclerotic heart disease and CHF, dementia, ADL

Methods (continued)

• Multilevel multivariate statistical analysis– Two-level random intercept logistic

regression modeling with logit link function – HLM 5; Hierarchical Linear Modeling;

Scientific Software International, Inc. Lincolnwood, IL

2000-2001 2000-2001 (Cohort One)(Cohort One)

2001-2002 2001-2002 (Cohort Two)(Cohort Two)

Original random sample 22,317 21,773

Nursing Homes 277 260

Exclusions:

Coverage Survey or MDS data not available

2,904 (13%) 2,907 (13%)

Terminal illness, under Hospice Care, or HIV/AIDS

542 (2.4%) 521 (2.4%)

Vaccination Status Unknown 5,130 (22.9%) 3,411 (15.7%)

Final Cohort Size Final Cohort Size 13,267 (59.4%)13,267 (59.4%) 13,891 (63.8%)13,891 (63.8%)

Number of Nursing HomesNumber of Nursing Homes 273273 259259

Study Cohorts

Results

Results: Vaccination Rates

2000-2001Cohort One(N=13,267)

2001-2002Cohort One(N=13,891)

Received Influenza

Vaccine61% 61%

Received Pneumococcal Vaccine

39% 44%

Vaccination Status

05

1015202530354045

Cohort One Cohort Two

% V

acci

nate

d

Both Flu Pne

Demographic Characteristics Cohort 2000-2001

Both VaccinesN = 6,130

Flu OnlyN =

5,160

Pneumo Only

N = 1,007

NeitherN = 1,063

Male, % 27.7 29.3 28.9 29.4

White, % 79.7 80.3 81.5 83.4

Age Groups, %

Under 65 years 6.0 5.6 6.8 5.9

65 to 74 11.9 12.6 14.1 16.9

75 to 84 34.8 34.6 36.8 36.3

85 years or older 47.3 47.3 43.3 40.8

Co-Existing Conditions (%) Cohort 2000-2001 Both

VaccinesFlu Only

Pneumo Only Neither

Heart disease 29.7 30.8 33.4 30.9

COPD 16.6 16.7 16.4 20.8

Diabetes 23.2 23.7 26.0 24.2

Renal failure 4.4 5.1 5.3 6.7

Dementia 53.6 54.2 45.8 35.0

Cancer 6.7 6.3 6.9 11.7

Stroke 24.5 23.6 22.6 18.3

Mean ADL 11. 6 10.9 10.8 10.4

% Dead

Cohort One Cohort Two

Vaccination

Both Vaccines 11.7 12.4

Influenza Only 14.1 15.2

Pneumo Only

15.4 17.02

None 19.5 21.1

Association Between Vaccination and All-Cause Mortality, 2000-2002

Association Between Vaccination and All-Cause Mortality, 2000-2002

*Control Variables: diabetes, stroke, cancer, renal failure, heart disease, dementia, ADL score, sex, age

Adjusted* RR (CI)Adjusted* RR (CI)

Cohort One Cohort Two

Received Both Vaccines 0.55 (0.49 – 0.69) 0.58 (0.521 – 0.67)

Received Influenza Only 0.75 (0.62 – 0.86) 0.73 (0.648 – 0.87)

Received Pneumo. Only 0.81 (0.65 – 0.98) 0.80 (0.676 – 0.9)

Received None (Ref)

Facility-Level Vaccination Coverage

• In initial analysis, without exclusion of residents with unknown vaccination status– >80% coverage with influenza

significantly and independently associated with decreased risk of mortality

• After exclusion, this association became insignificant

Summary

• The first prospective study of Nursing Home residents to demonstrate a significant protective effect of pneumococcal vaccination on mortality.

• Confirmed the important role of influenza vaccination in preventing the adverse outcome.

Limitations

• Facility selection non-randomized

• Vaccination status non-randomized

• Possibility of exclusion bias

• Possibility of misclassification bias in ascertaining vaccination status

• Possibility of unmeasured confounders

Health Policy Implications• Unvaccinated residents are at increased risk for

adverse outcomes

• Failure to vaccinate residents of long term care facilities is a patient safety issue

• Wider implementation of standing orders programs or other effective interventions to increase vaccination rates

• A better understanding of the barriers to vaccination in this setting is needed

• Poor documentation of vaccination status in NHs

Acknowledgments

• CDC– Jeremy Miller

• Oklahoma Foundation For Medical Quality– Jennifer O’Hagan

• CMS– Jackie Harley– Kathy Pirotte– Peter Houck

CategoryCategory

Skilled Nursing Facility/Nursing Facility (dual certification) 52%

Skilled Nursing Facility/Nursing Facility (distinct part certified) 39%

Skilled nursing facility 4%

Nursing 4%

SizeSize

small 26%

medium 41%

large 33%

OwnershipOwnership

Government 12%

For profit 53%

Non-profit 34%

Nursing Home Characteristics (n=249)

Results: Vaccination Rates

2000-2001Cohort One(N=13,267)

2001-2002Cohort One(N=13,891)

Received Influenza

Vaccine84.7% 75.9%

Received Pneumococcal Vaccine

53.1% 54.5%