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. et. Al. JAMA 2003;289:179
2Thompson
Documented Influenza and Pneumococcal Vaccination Among US Nursing Home Residents, 1995-1999
100 80
% Vaccinated
Healthy People 2010 Goal
63 60 40
64
66 1995 1997 1999
38 24 28
20 0 Influenza Pneumococcal
Buikema AR, Singleton JA, et al. [abstract] Centers for Disease Control and Prevention, 35th National Immunization Conference.
Vaccine 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;123:518-527 LA, et al. N Engl J Med 2003;348:1747-55, 2003
2 Jackson
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 Project
Centers for Disease Control and Prevention and Center for Medicare and Medicaid Services
14 States
DC
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
Study Cohorts
2000-2001 (Cohort One) Original random sample Nursing Homes Exclusions: Coverage Survey or MDS data not available Terminal illness, under Hospice Care, or HIV/AIDS Vaccination Status Unknown Final Cohort Size Number of Nursing Homes 2,904 (13%) 542 (2.4%) 5,130 (22.9%) 13,267 (59.4%) 273 2,907 (13%) 521 (2.4%) 3,411 (15.7%) 13,891 (63.8%) 259 22,317 277 2001-2002 (Cohort Two) 21,773 260
Results
Results: Vaccination Rates
2000-2001 Cohort One (N=13,267) 2001-2002 Cohort One (N=13,891)
Received Influenza Vaccine Received Pneumococcal Vaccine
61%
61%
39%
44%
Vaccination Status
45 40 35 30 25 20 15 10 5 0 Cohort One Both Flu Pne Cohort Two
% Vaccinated
Demographic Characteristics Cohort 2000-2001
Both Vaccines N = 6,130 Male, % White, % Age Groups, % Under 65 years 65 to 74 75 to 84 85 years or older 6.0 11.9 34.8 47.3 5.6 12.6 34.6 47.3 6.8 14.1 36.8 43.3 5.9 16.9 36.3 40.8 27.7 79.7 Flu Only N = 5,160 29.3 80.3 Pneumo Only N = 1,007 28.9 81.5 Neither N = 1,063
29.4 83.4
Co-Existing Conditions (%) Cohort 2000-2001
Both Vaccines Heart disease COPD Diabetes Renal failure 29.7 16.6 23.2 4.4 Flu Only 30.8 16.7 23.7 5.1 Pneumo Only 33.4 16.4 26.0 5.3 Neither 30.9 20.8 24.2 6.7
Dementia
Cancer Stroke Mean ADL
53.6
6.7 24.5 11. 6
54.2
6.3 23.6 10.9
45.8
6.9 22.6 10.8
35.0
11.7 18.3 10.4
Association Between Vaccination and AllCause Mortality, 2000-2002
% Dead
Cohort One Vaccination
Both Vaccines Influenza Only Pneumo Only None
Cohort Two
11.7
14.1 15.4
12.4
15.2 17.02
19.5
21.1
Association Between Vaccination and All-Cause Mortality, 2000-2002
Adjusted* RR (CI)
Cohort One
Received Both Vaccines Received Influenza Only Received Pneumo. Only Received None (Ref)
*Control Variables: diabetes, stroke, cancer, renal failure, heart disease, dementia, ADL score, sex, age
Cohort Two
0.58 (0.521 – 0.67) 0.73 (0.648 – 0.87) 0.80 (0.676 – 0.9)
0.55 (0.49 – 0.69) 0.75 (0.62 – 0.86) 0.81 (0.65 – 0.98)
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
• CMS
– Jackie Harley – Kathy Pirotte – Peter Houck
• Oklahoma Foundation For Medical Quality
– Jennifer O’Hagan
Nursing Home Characteristics (n=249)
Category Skilled Nursing Facility/ Nursing Facility (dual certification)
52% 39% 4% 4% 26% 41% 33%
12% 53% 34%
Skilled Nursing Facility/ Nursing Facility (distinct part certified)
Skilled nursing facility Nursing Size small medium large Ownership Government For profit Non-profit
Results: Vaccination Rates
2000-2001 Cohort One (N=13,267) 2001-2002 Cohort One (N=13,891)
Received Influenza Vaccine Received Pneumococcal Vaccine
84.7%
75.9%
53.1%
54.5%