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[Human Vaccines 3:3, 57-60, May/June 2007]; ©2007 Landes Bioscience

Research Paper

Predictors of Pneumococcal Vaccination Uptake in Hospitalized Patients Aged 65 Years and Over Shortly Following the Commencement of a Publicly Funded National Pneumococcal Vaccination Program in Australia Iman Ridda1,* Raina C. MacIntyre1,2 Richard I. Lindley3 Peter B. McIntyre1 John Sullivan6,7 Gwendolyn Gilbert8 Pramesh Kovoor4 Nicholas Manolios5 John Fox9

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7The Australian Red Cross Blood Services; Sydney NSW, Australia

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2Discipline of Pediatrics and Child Health; 3Discipline of Medicine, Geriatric Medicine; 4Discipline of Medicine, Cardiology Department; 5Discipline of Medicine, Rheumatology Department; 6Transfusion Medicine & Immunogenetics Research Unit; Central Clinical School; The University of Sydney; Sydney NSW, Australia

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1National Centre for Immunisation Research and Surveillance; Sydney NSW, Australia

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In January 2005, Australia became the first country to introduce a publicly funded pneumococcal vaccination program for persons 65 years and older which is free at point of service, although the vaccine cost had previously been partially subsidized. Hospitalization in this age group is an important indicator of risk of invasive pneumococcal disease but vaccine uptake has been suboptimal. To determine vaccination rates and predictors of vaccination in the elderly hospitalised patients before and after January 2005. We validated vaccination status against general practitioner (GP) records for patients aged ≥ 65 years admitted to a large teaching hospital in Sydney between 16th of May 2005 and the 20th of February 2006 and examined predictors of vaccination. Commencement of the new program resulted in a significant increase in vaccination uptake from 39% of inpatients prior to the free program to 73% in the same cohort of inpatients post January 2005. We found that patient recall of vaccination status was not reliable. Self-report of pneumococcal vaccination had a sensitivity of 0.53 and a specificity of 0.55, highlighting that validation of vaccination status is required. Age over 80 years and dementia significantly predicted under-vaccination. This highlights the importance of integrating free vaccine supply and delivery in primary care to achieve high vaccination coverage. However, demented patients and the very elderly remain under-vaccinated, despite being admitted to hospital for active management of acute conditions.

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8Centre for Infectious Diseases and Microbiology, Institute of Clinical Pathology and Medical Research; Westmead Hospital; Sydney NSW, Australia 9Discipline

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of Medicine, Department of Orthopaedic Surgery; Westmead Hospital; Sydney NSW, Australia

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*Correspondence to: Iman Ridda; The Children Hospital, NCIRS; Cnr Hawksbury Rd and Hainsworth St.; Westmead, NSW 2145 Australia; Tel.: +011.612.98451432; Fax: +011.612.98451418; Email: [email protected]. au

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Original manuscript submitted: 11/30/06 Manuscript accepted: 01/30/07

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Previously published online as a Human Vaccines E-publication: http://www.landesbioscience.com/journals/vaccines/abstract.php?id=3925

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Key words

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pneumococcal vaccine, hospitalized elderly, increased vaccination uptake

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Streptococcus pneumoniae is the commonest cause of pneumonia, and can affect people of all ages. It is associated with significant morbidity and mortality, particularly in the very young, the elderly1 and people with immune deficiencies and chronic illness.2,3 Pneumonia can be categorized into three types in the elderly namely: communityacquired pneumonia which is the most common; nursing home acquired pneumonia and nosocomial pneumonia. Nursing home patients are a special population as they have different characteristics and tend to be sicker than community-dwelling patients.4 This population also has a higher incidence of aspiration pneumonia than the rest of the community and is the most common cause for hospitalization.5 Nosocomial pneumonia not infrequently complicates hospital admission for other causes. The incidence of pneumonia increases markedly among the elderly and is a major cause of ����������������������������������������������������� hospitalization and death. The mortality rate is 20% among ������������ those ≥ 65 years, as high as 40% in persons > 85 years2 and over ���� 50% ������������������������������������������ in the institutionalised high-risk groups.6 Throughout the world there is an increase of pneumococcal resistance to antibiotics,7,8 with unsuccessful treatment likely to be complicated by extrapulmonary spread of the infection. Furthermore, the ageing of the Australian population has ensured that the health of the elderly is a national priority. The next twenty years will see an increase in the ≥ 65 year-olds from 12.5% to 18%, and a doubling of those over 85 years old.9 The elderly are most prone to dementia, particularly those at risk for stroke. In Australia, about 5% of people aged ≥65 years and 20% of people over the age of 80 years are affected by some form of dementia.10 Dementia is defined as symptoms, including impaired memory and changes in personality, and behavior which is of a degree sufficient to impair functioning in daily living. Human Vaccines

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Predictors of Pneumococcal Vaccination Uptake in Elderly Patients

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The criteria for the diagnosis of dementia include impairment of attention, orientation, memory, judgment, language, motor and spatial skills, and function. The Mini Mental State Examination (MMSE) is the most commonly used test for memory problems and facilitate classification of dementia. Hence we used this test in our sample population to determine the diagnosis of dementia. MMSE is a good instrument for assessing cognitive function it takes up to ten minutes and questions involve orientation, registration (naming three objects), attention and calculation, recall (the previous three objects) and language. A cut off point for diagnosing dementia on the MMSE is ≤ 19 out of a maximum of 30 points where as a score of 20 points or more needed for a person to be able to consent for themselves. Sample size calculation. For a total of 2000 patients admitted between May 2005 and February 2006, a sample size of 88 is required to determine a vaccination rate between 50% and 60% with 95% confidence interval and 80% power, for target differences in vaccination rates an even smaller sample size was required. Data entry. Baseline data were collected by interviewer as well as medical record review and the interviewer administered questionnaires. Data then entered into Access program (Microsoft Access XP 2006, version.7) by the data manger. The data represent responses to questions about simple demographic characteristics, current medical history and about influenza and pneumococcal vaccination history by self report and GP records. SPSS software (SPSS Inc. Chicago, Il, USA) was used for data analysis. Descriptive univariate analysis was performed, followed by logistic regression for predictors of vaccination. A 2 by 2 table analysis for test characteristics of patient self report against GP vaccination records as the gold standard was also performed.

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The 23-valent polysaccharide pneumococcal vaccine (23-PPV) has been in use since 1983 and covers over 90% of Streptococcus pneumoniae strains which cause invasive pneumococcal disease in adults.11 The National Health and Medical Research Council (NHMRC) of Australia recommended that adults aged ≥ 65 years should be immunized with PPV.12 However, despite these guidelines, and partially subsidized vaccine cost through the Pharmaceutical Benefits Scheme, uptake of pneumococcal vaccine was estimated to be only 25–30% in the elderly,2,13-15 well below the coverage of 70% achieved for influenza vaccination, which has been free at the point of delivery in primary care for persons ≥ 65 years since 1999.16 In January 2005, Australia introduced the same arrangements for pneumococcal vaccination as had previously pertained for influenza vaccine—the vaccine was supplied to general practitioners’ offices for provision free of charge to all persons aged ≥ 65 years. Hospitalization represents an opportunity to identify people who are unimmunized and are at risk of pneumococcal disease. Hospitalized elderly represent a subgroup at particular risk, as they are more likely to have co morbid illness and are at increased risk of invasive pneumococcal disease. Despite this the pneumococcal vaccine coverage is low among the hospitalized elderly patients.17,18 The aim of this study was to determine vaccination rates, validity of self-report and predictors of vaccination in hospitalized adults aged ≥ 65 years admitted to a large teaching hospital in Sydney between 16th of May 2005 to the 20th of February 2006.

Patients and Methods

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The study is set out to test the hypothesis that the provision of free vaccine results in rapid increase in vaccination uptake. Hospitalized patients admitted to the geriatric, cardiology, rheumatology and orthopedic wards were studied at Westmead Hospital. The hospital is located in the west of Sydney and serves as tertiary referral base for the western metropolitan area. It also acts as the District Hospital for the immediate surrounding community. The population number for Sydney west area health service reached 1,114,020 for 2006.19 This hospital does not have general medical units, and most elderly patients with complex co-morbidities who are not admitted under a disease-based speciality are admitted under the geriatric unit. Study population. We approached 833 of the total of 1997 patients who were admitted to the hospital between the 16th of May 2005 and the 20th of February 2006. A standard close-ended questionnaire was used for each patient; the respondents were given a chance to comments at the end of the interview. One trained interviewer was assigned for this project (IR). The interviewer asked patients about their pneumococcal and influenza vaccination status e.g., “Have you had your flu vaccine for this year and have you ever had the pneumococcal or pneumonia vaccine?” and verbal consent was obtained from them (or from a family member if demented) to contact their family doctor. The interviewer then validated self reported vaccination status against general practice (GP) records with the patients’ consent. All GP’s were contacted by phone asking for information about the patients’ influenza and pneumococcal vaccination status and dates of vaccination were obtained. A faxed letter was sent to those GP’s who did not respond to the initial phone contact. The study was approved by the Human Research Ethics Committees of Sydney West Area Health Service, The Children’s Hospital at Westmead and the University of Sydney, as well as by the New South Wales Guardianship Tribunal.

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Results

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Self report and validated vaccination status. We approached 833 of the 1997 admitted patients during the study period. The reminder were not approached for reasons such as being too unwell; communication difficulties; or refused to take part in the study by not providing any relevant information or admitted at times when no trial staff was available (e.g., night, weekends) the majority of these fell into the last category. Although it is a convenient sample the approached patients were sufficient to represent patients at risk who were admitted to the hospital as those we did not interview had similar predictors. The main admission diagnoses for the approached patients were fall and fractures (112/833), typical geriatric syndromes such as functional disability, pressure ulcers, gait and balance problems, dementia and delirium (500/833), cardiac problems (162/833) and stroke (59/833). Of these patients, 121 (15%) reported that they had not had the influenza vaccine in �������������������������������������� the study year��������������������� , 250 (30%) reported that they did not know or were unsure and 462 (55%) reported that they had been vaccinated against influenza in the past year. For the pneumococcal vaccine, 202 (24%) reported that they had not had the vaccine, 321 (39%) reported that they did not know or were unsure if they were vaccinated and 310 (37%) reported that they had been vaccinated against pneumonia. We were able to validate these self-report for 653/833 (78%) patients. The reminder either did not give consent to contact their GP; or the GP contact information was incomplete; or the GP did not reply; or the GP could not find any recorded information for their patient.

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2007; Vol. 3 Issue 3

Predictors of Pneumococcal Vaccination Uptake in Elderly Patients

Table 1

Table 2

Vaccination by GP records

S elf Reported

GP Validated Vaccinated

Vaccinated

95% CI

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257

Gender

1.14

0.75 -1.71

0.548

88

169

Dementia

0.27

0.17 - 041

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0.48

0.31 – 0.73

or =65 years and among persons aged 18-64 years with high-risk conditions-United States, 2003. MMWR - Morbidity and Mortality Weekly Report. 24. Davis MM, Taubert K, Benin AL, Brown DW, Mensah GA, Baddour LM, et al. Influenza vaccination as secondary prevention for cardiovascular disease: A science advisory from the american heart association/american college of cardiology. Circulation. 25. Centers for disease control and prevention (CDC). Influenza and pneumococcal vaccination coverage among persons aged > or =65 years and persons aged 18-64 years with diabetes or asthma--United States, 2003. MMWR - Morbidity and Mortality Weekly Report. 26. Nichol KL, Nordin J, Mullooly J, Lask R, Fillbrandt K, Iwane M. Influenza vaccination and reduction in hospitalizations for cardiac disease and stroke among the elderly. New England Journal of Medicine. 27. Cornu C, Yzebe D, Leophonte P, Gaillat J, et al. Efficacy of pneumococcal polysaccharide vaccine in immunocompetent adults: A meta-analysis of randomized trials. Vaccine 2001; 19:4780-4790. 28. Jefferson T, Rivetti D, Rivetti A, Rudin M, Di PC, Demicheli V. Efficacy and effectiveness of influenza vaccines in elderly people: A systematic review. Lancet. 29. Nordin J, Mullooly J, Poblete S, Strikas R, Petrucci R, Wei F, et al. Influenza vaccine effectiveness in preventing hospitalizations and deaths in persons 65 years or older in Minnesota, New York, and Oregon: Data from 3 health plans. Journal of Infectious Diseases. 30. National health and medical research council. The Australian Immunisation Handbook. 8th ed. Canberra: Australian Government Publishing Service, 2003. 31. Donald RM, Baken L, Nelson A, Nichol KL. Validation of self-report of influenza and pneumococcal vaccination status in elderly outpatients. American Journal of Preventive Medicine 1999; 16(3):173-177. 32. Condon L. Maternal attitudes to preschool immunisations among ethnic minority groups. Health Education Journal 2002; 61(2):180-189. 33. Donald RM, Baken L, Nelson A, Nichol KL. Validation of self-report of influenza and pneumococcal vaccination status in elderly outpatients. American Journal of Preventive Medicine 1999; 16(3):173-177. 34. MacIntyre CR, Nolan T. Attitudes of Victorian vaccine providers to pertussis vaccine. Medical Journal of Australia 1994; 161(5). 35. Petrovic M, Roberts R, Ramsay M. Second dose of measles, mumps, and rubella vaccine: Questionnaire survey of health professionals. British Medical Journal 2001; 322(7278):8285. 36. Ramsay ME, Yarwood J, Lewis D, Campbell H, White JM. Parental confidence in measles, mumps and rubella vaccine: Evidence from vaccine coverage and attitudinal surveys. British Journal of General Practice 2002; 52(484):912-916. 37. MacIntyre C, Nolan T. Attitudes of Victorian vaccine providers to pertussis vaccine. Medical Journal of Australia 1994; 161[5]:295-9, (1994. Ref Type: Abstract). 38. Briss PA, Rodewald LE, Hinman AR, Shefer AM, Strikas RA, Bernie RR, et al. Reviews of evidence regarding interventions to improve vaccination coverage in children, adolescents, and adults. American Journal of Preventive Medicine 2000; 18(1 Suppl. 1):97-140. 39. Shefer A, Briss P, Rodewald L, Bernier R, Strikas R, Yusuf H, et al. Improving immunization coverage rates: An evidence-based review of the literature. Epidemiologic Reviews 1999; 21(1):96-142. 40. Szilagyi PG, Rodewald LE, Humiston SG, Pollard L, Klossner K, Jones AM, et al. Reducing missed opportunities for immunizations: Easier said than done. Archives of Pediatrics and Adolescent Medicine 1996; 150(11):1193-1200.

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actually vaccinated. We also found that when patients say they are unvaccinated, or do not know if they are vaccinated, that there is a high probability that they are vaccinated. Pneumococcal vaccination may result in a higher risk of local reactions and fever post-vaccination if inadvertently administered to already-vaccinated subjects, making it important to accurately establish the patients’ vaccination status.30 Another Australian study found that while there was some discrepancy between patient self-report and GP validation, agreement was reasonable.13 However, yet another study showed that patients have less�������������������������������������������������������� accurate recall with increasing time since vaccination.31 These early data from Australia, one of the first countries to provide universal free pneumococcal vaccine to the elderly, show that public funding of vaccination programs have a major impact on vaccination uptake, but that the groups at highest risk remain under-vaccinated. Health care provider attitudes, rather than patient attitudes, are probably the most important factor which determine vaccination uptake in target groups.32-36 In summary, people are likely to accept vaccination if their doctor recommends it. As such, it is important that doctors are advocates of vaccination, particularly for the high-risk sub-group in our study.37-40

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