ABSTRACT
There is scarce data about pneumococcal vaccination coverages among adults in recent years. We investigated current pneumococcal vaccination coverages in Catalonia, Spain, with a cross-sectional population-based study including 2,033,465 individuals aged 50 y or older assigned to the Catalonian Health Institute at 01/01/2015 (date of survey). A previously validated institutional research clinical Database was used to classify study subjects by their vaccination status for both 23-valent pneumococcal polysaccharide vaccine (PPSV23) and 13-valent pneumococcal conjugate vaccine (PCV13), to identify comorbidities and underlying conditions, and establish the risk stratum of each individual: High risk stratum: functional or anatomic asplenia, cochlear implants, CSF leaks, or immunocompromising conditions; medium risk stratum: immunocompetent persons with history of chronic cardiac or respiratory disease, liver disease, diabetes mellitus, alcoholism and/or smoking; low risk stratum: persons without high or medium risk conditions. Of the total 2,033,465 study population, an amount of 789,098 (38.8%) had received PPVS23, whereas 5031 (0.2%) had received PCV13. PPSV23 coverages increased largely with increasing age: 4.8% in 50–59 y vs 35.5% in 60–69 y vs 71.9% in 70–79 y vs 79.5% in 80 y or older; p < 0.001). PCV13 coverages also increased with age, although they were very low in all age groups. PPSV23 coverages were 59.2% in high risk stratum, 48.3% in medium risk stratum and 28.1% in low risk stratum (p < 0.001). For the PCV13, uptakes were 1.2%, 0.3% and 0.1% in high, medium and low stratum, respectively (p < 0.001). In conclusion, pneumococcal vaccination coverages in Catalonian adults are not optimal, being especially small for the PCV13 (even in high-risk subjects).
Introduction
Infections caused by Streptococcus pneumoniae are an important cause of morbidity and mortality in high-risk and older adults.Citation1 Since 2012, two pneumococcal vaccines are available for use in adults: the “classical” 23-valent pneumococcal polysaccharide vaccine (PPSV23) and the “new” 13-valent protein-polysaccharide conjugate vaccine (PCV13).Citation2,3
The Healthy People 2020 goal is to achieve at least 90% coverage for pneumococcal vaccination among high-risk adults and elderly people (i.e, 65 y or older).Citation4 However, few population-based studies have been published evaluating this issue at present.
In Catalonia, a region in Northeastern Spain with approximately 7 million people, PPSV23 is publicly funded for all individuals over 60 y (with and without risk factors) and persons 18–59 y with certain high-risk conditions (immunodeficiency, chronic heart or pulmonary disease, diabetes mellitus and/or severe liver disease) since the 2000 s.Citation5 PCV13 is publicly funded only for some high-risk individuals (basically anatomical or functional asplenia and immunocompromised patients) since 2012. The PCV13 is also prescribed by some clinicians for patients with other risk conditions (COPD, asthma, heart diseases, etc) although it is not publicly funded in these patients.Citation6
This report describes current antipneumococcal vaccination uptakes for both vaccines among Catalonian middle-aged and older adults, and assesses vaccine coverages by age and risk strata of the population.
Results
A total of 790,063 (38.9%) of the 2,033,465 study population had received any pneumococcal vaccine (PPSV23 or PCV13) at any time. Overall pneumococcal vaccination coverage (PPSV23 or PCV13) increased considerably with increasing age (4.9% in 50–59 y vs 35.6% in 60–69 y vs 72.0% in 70–79 y vs 79.5% in people 80 y or older; p < 0.001) and was lower in men than in women (37.6% vs 40.0%; p < 0.001). By residential area, this coverage was 40.6% in people living in rural areas and 38.6% in urban areas (p < 0.001).
Of the total study population, an amount of 789,098 (38.8%) had received at least one dose of PPSV23 at any time (269,073 of them within the last 5 years), whereas 5031 (0.2%) persons had received PCV13. Of the 789,098 persons who had received PPSV23, an amount of 91,738 (11.6%) had been revaccinated (90,215 with a second dose and 1,523 with 3 or more doses).
PPSV23 uptake (at least one dose of PPSV23 at any time) was significantly greater in people living in rural areas than in urban areas (40.5% vs 38.5%; p < 0.001). For the PCV13, uptakes were also higher in rural than in urban areas (0.4% vs 0.2%; p < 0.001). By sex, PPSV23 uptake was slightly lower in men than in women (37.5% vs 39.9%; p < 0.001). Considering PCV13, uptakes were very small in both men (0.3%) and women (0.2%).
PPSV23 uptakes increased largely with increasing age: 4.8% in 50–59 y vs 35.5% in 60–69 y vs 71.9% in 70–79 y vs 79.5% in 80 y or older (p < 0.001). Considering the total study subjects in each age strata, the proportion of revaccinated subjects (more than one dose of PPSV23) were 1.2% in 50–59 years, 8.7% in 60–69 years, 5.4% in 70–79 y and 3.5% in 80 y or older (p < 0.001). PCV13 uptakes also increased with age, although they were very low in all age groups (0.1% in 50–59 y vs 0.2% in 60–69 y vs 0.4% in 70–79 y vs 0.4% in people 80 y or older; p < 0.001). shows vaccination uptakes for both PPSV23 and PCV13 according to age strata and time elapsed since vaccination.
Table 1. Pneumococcal vaccine coverages according to age strata and time elapsed since vaccination.
By risk strata, overall pneumococcal vaccination coverage (PPSV23 or PCV13) was 59.4% in high risk stratum, 48.4% in medium risk stratum and 28.1% in low risk stratum (p < 0.001). shows vaccine coverages separately for PPSV23 and PCV13, according to age and risk strata.
Table 2. Pneumococcal vaccine coverages according to risk strata and time elapsed since vaccination.
If we consider dual vaccination (PPSV23 plus PCV13), it was observed in 4066 (0.2%) study subjects. Dual vaccination coverage was similar in both men and women (0.2%), being higher in people 65 y or older than in persons 50–64 years-old (0.3% vs 0.1%; p < 0.001) and greatest in high-risk subjects (1% in high risk stratum vs 0.2% in medium risk stratum vs 0.1% in high risk stratum; p < 0.001).
show, respectively, crude and multivariable-adjusted analysis estimating odds ratios (ORs) for PPSV23 vaccination, PCV13 vaccination and any vaccination (PPSV23 or PCV13) considering the distinct study covariables.
Table 3. Unadjusted odds ratios for pneumococcal vaccination (PPSV23, PCV13, any vaccine) according to distinct study covariables.
Table 4. Adjusted odds ratios for pneumococcal vaccination (PPSV23, PCV13, any vaccine) according to distinct study covariables.
In the multivariable analysis, age was the strongest predictor for PPSV23 vaccination, with more than a 70 times higher probability of vaccination for persons aged 80 y or older as compared with persons 50–60 y (OR: 75.23; 95% confidence interval [CI]: 74.16–76.31). If we consider PCV13, the strongest predictor for vaccination was the risk stratum, observing that persons in high risk stratum (immunocompromising conditions) had more than 13-times greater probability of vaccination as compared with persons in low risk stratum (OR: 13.59; 95% CI: 12.47–14.82).
Discussion
To our knowledge, there is very scarce population-based data about pneumococcal vaccination coverages among adults in recent years (i.e., after PCV13 approval for adults in 2012).
The present large population-based study, which includes more than 2 million people aged 50 y or older in Catalonia, shows a global vaccination coverage of approximately 39 percent (9.4% among persons 50–64 years-old and 69.6% among persons 65 y or older). Almost all immunized persons in our setting had received the classical PPSV23, whereas the new PCV13 had been used very scarcely (<1%) at the time of the study (01/01/2015).
In the multivariable analyses, age was the strongest predictor for PPSV23 vaccination, whereas risk stratum was more predictive for PCV13 vaccination. This data fits with current pneumococcal vaccine recommendations in Catalonia, where PPSV23 is recommended (and publicly funded) for all persons 60 y or older (with or without underlying conditions) whereas PCV13 is only publicly funded for high-risk patients.
Our population vaccination coverage (38.9%) appears to be so far from the 90% goal of the Healthy People 2020.Citation4 However, in order to better interpret our results, it must be highlighted that population vaccination coverage in this study was estimated considering the total population over 50 y. We note that the coverage level would be considerably greater (up to 53.3%) if those subjects 50–64 years-old without risk factors (theoretically non eligible for pneumococcal vaccination in most countries) were excluded from the analysis.
In fact, some population subgroups in our study show coverages near to the 2020 objective. If we consider exclusively elderly people (i.e, 65 y or older), the observed PPSV23 vaccination coverage reached around 70 percent, which is considerably greater than the 44% vaccination coverage observed among elderly persons in the same geographical area at the beginning of the past decade.Citation5 PPSV23 uptakes were lower among persons 50–64 years-old, even if they had immunocompromising conditions (high risk stratum: 19.7% coverage) or chronic illness (medium risk stratum: 16.4% coverage). Our results agree with data reported in other settings showing poor pneumococcal vaccination coverages in high-risk adults under 65 years-old.Citation7,8
If we consider PCV13, its coverage was insignificant (0.2%) in our population at the end of 2014, despite the vaccine having been approved for use in adults since 2012. The lack of public reimbursement could explain the low PCV13 uptake rates observed among immunocompetent persons in medium and low risk strata , but it can not explain the little PCV13 coverage among immunocompromised and/or high-risk patients (high risk stratum) where PCV13 is publicly funded in our setting.Citation6 In the present authors opinion, together with its considerably greater price as compared with the PPSV23, some doubts about possible impact and cost-effectiveness of PCV13 vaccination in adults (e.g., low serotype-vaccine coverage to prevent all IPD cases, small number of total CAP cases prevented in the CAPITA trial)Citation9-13 could explain the very scarce use of this vaccine in our setting. This study found that coverage was higher for both vaccines for people living in rural areas rather than urban areas. In Catalonia, general practitioners in rural areas have less patients assigned to them than general practitioners in urban areas. As a consequence, the average time for a visit and the probability of recommending a vaccination is higher in rural areas.
We note that, in contrast with age-based vaccination strategies (which are easier to implement and usually achieve higher levels of vaccine uptake), risk-based vaccination strategies need to identify those individuals with specific underlying conditions/diseases (which is a more difficult strategy that usually fails to achieve high coverage levels).Citation14
Our results do not substantially differ with data observed in the USA during 2013, where pneumococcal vaccination coverage only reached 21.2% among persons aged 18–64 years-old with high-risk conditions but it was 69.5% among the general elderly population (65 y or older).Citation7,8 In European settings, there is scarce population-based data evaluating pneumococcal vaccination coverages among adults. Estimates of PPSV23 uptakes can be inferred from the number of vaccine doses distributed in each country, but these estimates show great disparities in PPSV23 uptakes (with higher levels of vaccine use in countries with age-based recommendations and public reimbursement).Citation14 Estimates of PPSV23 coverages among elderly populations in Western European countries vary between 20% and 69% in distinct settings (probably reflecting national recommendations and program funding).Citation5,14-20 Considering that the use of the PCV13 in adults has only been approved recently, there is no published data about PCV13 uptakes.
We note that, at present, recommendations for pneumococcal vaccination in adults are not homogeneous in distinct countries, scientific societies and/or clinical guidelines.Citation6,14,21-27 Some countries recommend routine PPSV23 vaccination for all persons 65 y of age, (with or without risk conditions), other countries recommend vaccination starting at a younger age, and others recommend PPSV23 only for at-risk groups.Citation17,26,27 In addition, there is also heterogeneity for PCV13 recommendations and funding for adults in distinct settings.Citation6,22,23,27 These concerns greatly difficult the comparison of vaccination coverages between distinct countries. In Spain, revaccination is recommended for those persons who received PPSV23 before the age of 65 for any indication, but routine revaccination with PPSV23 is not recommended among the general people over 65 y because of insufficient data on clinical benefits and the duration of protection.Citation6
This study has several strengths. Design was population-based and study population (which included approximately 80% of overall Catalonian people 50 y or older) was representative and large enough to estimate accurately pneumococcal vaccination coverages (for both PPSV23 and PCV13) according to distinct age and risk strata of interest. In addition, the validity of clinical data source was previously checked.Citation28 Information bias may have occurred if some comorbidity or vaccination was not recorded, but such misclassification would likely be very small considering that prevalence observed for distinct risk conditions and vaccination coverages fit with data previously reported in the literature.Citation5
Ethnicity information was not available in the present study, which may be considered as a limitation given that ethnic disparities in pneumococcal vaccination have been described in adults in other settings.Citation7,8 In Spain, to our knowledge, there are no published studies reporting pneumococcal vaccination coverages based on ethnic groups in adults, but a recent study assessing pneumococcal vaccination in children has reported considerably greater pneumococcal vaccination coverage in native Spanish children (57%) than in immigrant children (26%).Citation29
In summary, the present study shows that almost 40 percent of overall Catalonian people 50 y or older (with or without risk conditions) have received the classical PPSV23, whereas less than one percent have received the new PCV13. Maximum coverages appear in older age-strata, reaching around 70 percent among persons 65 y or older (with or without risk conditions). Although coverages increased by risk strata, less than 60 percent of overall persons considered at high-risk (high risk stratum) had received pneumococcal vaccination. This data supports the need of effective programs for pneumococcal vaccination, especially among those persons under 65 y who have chronic illnesses and/or high-risk factors (where coverages are currently much lower than in elderly persons with or without risk conditions). To facilitate clinical practice and, likely, improve current pneumococcal vaccination uptakes, more homogeneous pneumococcal vaccine recommendations/guidelines for adults are needed. When pneumococcal vaccine is recommended, the efficiency of delivery may be improved offering the vaccine alongside other vaccines (such as influenza or tetanus) which could also increase uptake.
Methods
This is a cross-sectional study involving 2,033,465 individuals aged 50 y or older, who were registered in any Primary Health Care Centre (PHCC) of the Catalonian Health Institute on January 1, 2015 (date of survey). The study was approved by the ethical committee of the institution (file P14/134) and was conducted in accordance with the general principles for observational studies.
In Catalonia, there are 358 PHCCs (comprised of doctors, nurses, social workers and support staff) which are distributed by geographical area and are responsible for the health care of the population in their areas. The Catalonian Health Institute manages 274 PHCCs (76.5%), serving a population of approximately 5 million people; the remaining 84 PHCCs are managed by other providers. Doctors and nurses systematically use electronic medical records to record diagnoses, prescriptions, vaccinations and other clinical, patient management and administrative activities.
The Catalonian Health Institute Information System for the Development of Research in Primary Care (“SIDIAP” database) compiles coded clinical information from the Electronic PHCC’s records,Citation30 and it has been used as main data source for this report. Quality criteria for clinical data of the SIDIAP research database have been reported in a validated comparison process.Citation28 The SIDIAP sample is representative of the general Catalan population in terms of geography, age and sex distributions, according to the official 2010 census.Citation30 The “SIDIAP” research database was used to classify study subjects by their pneumococcal vaccination status as well as to identify comorbidities, underlying conditions and establish the risk stratum of each individual.
Pneumococcal vaccination status (for both PPSV23 and PCV13) was determined by reviewing the electronic clinical records of the “SIDIAP” database, which contains specially designated fields for pneumococcal vaccinations (virtually all of them are administered at the PHCCs in the Catalonian Health System). We assumed that information in electronic clinical records was complete, so a subject was considered as unvaccinated when a vaccination was not recorded. Persons were considered vaccinated against pneumococcus if they had received at least one dose of PPSV23 or PCV13. Study subjects were also classified according to the number of doses received (revaccination) and time elapsed since vaccination (last dose).
Study subjects were grouped into 3 risk strata on the basis of the degree of immunocompromise and risk for pneumococcal disease.Citation31 High risk stratum included persons with functional or anatomic asplenia, cochlear implants, CSF leaks, or immunocompromising conditions such as immunodeficiency (including AIDS),cancer (solid organ or haematological neoplasia), chronic nephropathy (nephrotic syndrome, renal failure, dialysis or transplantation), and long-term corticosteroid therapy or immunosupresive medication (20 mg/day of prednisone or equivalent). Medium risk stratum included patients without a level 1 condition but who had a history of chronic lung disease (chronic bronchitis, emphysema or asthma), liver disease (cirrhosis or alcoholic hepatitis), heart disease (congestive heart failure, coronary artery disease and cardiomyopathy), diabetes mellitus, alcoholism and/or smoking. Low risk stratum included persons without level 1 or level 2 conditions.
Statistical analyses
Chi-squared test was used to compare proportions of PPSV23/PCV13 vaccinated versus nonvaccinated in the initial univariate analyses. Unadjusted odds ratios (ORs) were calculated to estimate the probability of vaccination according to each one of the studied covariables (age strata, sex, residential area and risk strata for suffering pneumococcal infections). We did logistic regression analyses (method “enter” including all covariables with a significance level p < 0.20 in previous univariate analyses) to calculate multivariable-adjusted ORs for vaccination (PPSV23, PCV13 or any vaccine). Statistical significance was set at p < .05 (2-tailed). Data was analyzed using the SPSS 18 statistical package.
Disclosure of potential conflicts of interest
No potential conflicts of interest were disclosed.
Funding
This work is supported, in part, by a grant from the “Fondo de Investigación Sanitaria” (FIS) of the ”Instituto de Salud Carlos III” (call 2015) for the “Acción Estratégica en Salud 2013–2016 del Programa Estatal de Investigación Orientado a los Retos de la Sociedad,” framing in the “Plan Estatal de Investigación Científica y Técnica y de Innovación 2013–2016;” code file PI15/01230, cofinanced by the European Union through the “Fondo Europeo de Desarrollo Regional” (FEDER). This work is also funded by a grant from the IDIAP Jordi Gol, Barcelona (grant SIDIAP 13/049). The authors thank Angel Vila-Rovira for his help in the production of this paper..
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