Julio Morán

Vaccine effectiveness in preventing influenza hospitalizations in Navarre, Spain, 2010-2011: cohort and case-control study.

We evaluated the 2010-2011 seasonal influenza vaccine effectiveness in preventing hospitalizations. Using healthcare databases we defined the target population for vaccination in Navarre, Spain, consisting of 217,320 people with major chronic conditions or aged 60 years and older. All hospitalized patients with influenza-like illness (ILI) were swabbed for influenza testing. A total of 269 patients with ILI were hospitalized and 61 of them were found positive for influenza virus: 58 for A(H1N1)2009 and 3 for B virus. The incidence rates of hospitalization with laboratory-confirmed influenza were compared by vaccination status. In the Cox regression model adjusted for sex, age, children in the household, urban/rural residence, comorbidity, pandemic vaccination, pneumococcal vaccination, outpatient visits and hospitalization in the previous year, the seasonal vaccine effectiveness was 58% (95% CI: 16-79%). The nested test-negative case-control analysis gave an adjusted estimate of 59% (95% CI: 4-83%). These results suggest a moderate effect of the 2010-2011 seasonal influenza vaccine in preventing hospitalization in a risk population. The close estimates obtained in the cohort and the test-negative case-control analyses suggest good control of biases.

Effectiveness of the monovalent influenza A(H1N1)2009 vaccine in Navarre, Spain, 2009-2010: Cohort and case-control study

We defined a population-based cohort (596,755 subjects) in Navarre, Spain, using electronic records from physicians, to evaluate the effectiveness of the monovalent A(H1N1)2009 vaccine in preventing influenza in the 2009-2010 pandemic season. During the 9-week period of vaccine availability and circulation of the A(H1N1)2009 virus, 4608 cases of medically attended influenza-like illness (MA-ILI) were registered (46 per 1000 person-years). After adjustment for sociodemographic covariables, outpatient visits and major chronic conditions, vaccination was associated with a 32% (95% CI: 8-50%) reduction in the overall incidence of MA-ILI. In a test negative case-control analysis nested in the cohort, swabs from 633 patients were included, and 123 were confirmed for A(H1N1)2009 influenza. No confirmed case had received A(H1N1)2009 vaccine versus 9.6% of controls (p<0.001). The vaccine effectiveness in preventing laboratory-confirmed influenza was 89% (95% CI: 36-100%) after adjusting for age, health care setting, major chronic conditions and period. Pandemic vaccine was effective in preventing MA-ILI and confirmed cases of influenza A(H1N1)2009 in the 2009-2010 season.

Incidencia de la varicela y el herpes zóster antes de la introducción de la vacunación sistemática infantil en Navarra, 2005-2006

Varicella is an acute and highly contagious disease produced by the varicella-zoster virus, which leaves lasting immunity. Herpes zoster is produced by reactivation of a latent infection of the same virus. The introduction of systematic and free vaccination against varicella in children of 15 months in Navarre from 2007 onwards can be expected to produce important epidemiological changes. For this reason we describe the previous epidemiological situation in the period from 2005 to 2006. We analysed all cases of varicella and herpes zoster registered in the electronic clinical files of primary care, in the database of hospital discharges and in the mortality register. Between 2005 and 2006, 9,908 cases of varicella were diagnosed (8.29 annually per 1,000 inhabitants), with 90% in children under 15 years old. There were 80 hospital admissions (8 for every 1,000 cases), complications in 2.5 out of every 1,000 cases, and there was one death due to this cause (0.1 per 1,000 cases). In the same period, 4,959 cases of herpes zoster were diagnosed (4.15 cases per 1,000 inhabitants), half in people over 55 years old. There were 179 hospital admissions (36 per 1,000 cases), whose average age was 77, and 83 presented complications (16.7 per 1,000 cases). This epidemiological pattern is similar to that found in other places before the introduction of the vaccine.

Effectiveness of the trivalent influenza vaccine in Navarre, Spain, 2010-2011: a population-based test-negative case-control study.

BackgroundSome studies have evaluated vaccine effectiveness in preventing outpatient influenza while others have analysed its effectiveness in preventing hospitalizations. This study evaluates the effectiveness of the trivalent influenza vaccine in preventing outpatient illness and hospitalizations from laboratory-confirmed influenza in the 2010–2011 season.MethodsWe conducted a nested case–control study in the population covered by the general practitioner sentinel network for influenza surveillance in Navarre, Spain. Patients with influenza-like illness in hospitals and primary health care were swabbed for influenza testing. Influenza vaccination status and other covariates were obtained from health care databases. Using logistic regression, the vaccination status of laboratory-confirmed influenza cases was compared with that of test-negative controls, adjusting for age, sex, comorbidity, outpatient visits in the previous 12 months, health care setting, time between symptom onset and swabbing, period and A(H1N1)pdm09 vaccination. Effectiveness was calculated as (1-odds ratio)x100.ResultsThe 303 confirmed influenza cases (88% for A(H1N1)pdm09 influenza) were compared with the 286 influenza test-negative controls. The percentage of persons vaccinated against influenza was 4.3% and 15.7%, respectively (p<0.001). The adjusted estimate of effectiveness was 67% (95% CI: 24%, 86%) for all patients and 64% (95% CI: 8%, 86%) in those with an indication for vaccination (persons age 60 or older or with major chronic conditions). Having received both the 2010–2011 seasonal influenza vaccine and the 2009–2010 pandemic influenza vaccine provided 87% protection (95% CI: 30%, 98%) as compared to those not vaccinated.ConclusionThe 2010–2011 seasonal influenza vaccine had a moderate protective effect in preventing laboratory-confirmed influenza.

Factors associated with continued adherence to influenza vaccination in the elderly.

OBJECTIVE We aimed to analyze the factors influencing continued adherence to influenza vaccination in elderly persons vaccinated in the preceding season. METHODS Using a population-based vaccination registry, we evaluated the proportion of persons vaccinated against influenza in Navarre, Spain, in the 2010-11 season among non-institutionalized persons aged 65 years or over who had been vaccinated in the 2009-10 season. Logistic regression was used to analyze the influence of sociodemographic, clinical and health care factors. RESULTS Of the 64,245 persons vaccinated against influenza in the 2009-10 season, 87% were vaccinated in the 2010-11 season. Continued adherence to vaccination increased with the number of physician visits per year. It was lower in women, in the 65-69 and ≥ 95 year age-groups, in those hospitalized or diagnosed with any major chronic condition in the previous year, and in persons with hematological cancer or dementia. Health districts and physicians with higher coverage in the previous season continued to have higher adherence in the following season. CONCLUSIONS People vaccinated against influenza in one season tend to be vaccinated in the following one. Sociodemographic, clinical and health care factors have a moderate effect on the continuity of vaccination, with the most important factor being the treating physician.

Variability in the performance of preventive services and in the degree of control of identified health problems: a primary care study protocol.

BackgroundPreventive activities carried out in primary care have important variability that makes necessary to know which factors have an impact in order to establish future strategies for improvement. The present study has three objectives: 1) To describe the variability in the implementation of 7 preventive services (screening for smoking status, alcohol abuse, hypertension, hypercholesterolemia, obesity, influenza and tetanus immunization) and to determine their related factors; 2) To describe the degree of control of 5 identified health problems (smoking, alcohol abuse, hypertension, hypercholesterolemia and obesity); 3) To calculate intraclass correlation coefficients.DesignMulti-centered cross-sectional study of a randomised sample of primary health care teams from 3 regions of Spain designed to analyse variability and related factors of 7 selected preventive services in years 2006 and 2007. At the end of 2008, we will perform a cross-sectional study of a cohort of patients attended in 2006 or 2007 to asses the degree of control of 5 identified health problems. All subjects older than16 years assigned to a randomised sample of 22 computerized primary health care teams and attended during the study period are included in each region providing a sample with more than 850.000 subjects. The main outcome measures will be implementation of 7 preventive services and control of 5 identified health problems. Furthermore, there will be 3 levels of data collection: 1) Patient level (age, gender, morbidity, preventive services, attendance); 2) Health-care professional level (professional characteristics, years working at the team, workload); 3) Team level (characteristics, electronic clinical record system). Data will be transferred from electronic clinical records to a central database with prior encryption and dissociation of subject, professional and team identity. Global and regional analysis will be performed including standard analysis for primary health care teams and health-care professional level. Linear and logistic regression multilevel analysis adjusted for individual and cluster variables will also be performed. Variability in the number of preventive services implemented will be calculated with Poisson multilevel models. Team and health-care professional will be considered random effects. Intraclass correlation coefficients, standard error and variance components for the different outcome measures will be calculated.

Caracterización de la pandemia de gripe A H1N1 2009 en Navarra

Background. To describe flu activity during the 2009-2010 pandemic in Navarre and compare it to previous seasons. Methods. An analysis was made of all flu cases reported in primary care and all the virological confirmations made in patients in primary care and in hospitals of Navarre between week 21 of 2009 and week 20 of 2010. Results. Influenza A (H1N1) Virus 2009 was detected in Navarre between week 23 of 2009 and week 2 of 2010, a period when 39 medically diagnosed cases of flu syndrome per 1,000 inhabitants were registered. The epidemic threshold was surpassed in two periods, with a peak in July and a greater one in November. The greatest incidence was reached in children aged between 5 and 14 years (121 per thousand), followed by the group of under fives. There were 224 hospitalisations (36 per 100,000 inhabitants) with confirmation of Influenza A (H1N1) Virus 2009, 8% of whom required admission to intensive care units and there were four deaths (0.6 per 100,000 inhabitants). The rate of hospitalisation was greater amongst children under five (163 per 100,000 inhabitants), while the probability of referral to intensive care increased with age. Conclusion. In spite of not having a specific vaccine available until the season was very well advanced, Influenza A (H1N1)Virus 2009 produced a flu wave with similar levels to those of other seasons and its repercussion in hospitalisations and serious cases was moderate.

Effect of comprehensive smoke-free legislation on asthma and coronary disease trends in Spanish primary care patients

Background To examine the impact of comprehensive smoke-free legislation (SFL) (Law 42/2010) on the incidence and prevalence of adult asthma and coronary disease in primary health care (PHC) patients from three Spanish regions, overall and stratified by sex. Methods Longitudinal observational study conducted between 2007 and 2013 in the population over 15 years of age assigned to 66 PHC teams in Catalonia, Navarre and the Balearic Islands. Crude rates and age-standardized (truncated: asthma ≥ 16 years and coronary disease ≥ 35 years) incidence and prevalence rates using the direct method based on the European Standard Population were estimated based on data from PHC electronic health records. Joinpoint analysis was used to analyse the trends of age-standardized incidence and prevalence rates. Trends were expressed as annual percentage change and average annual percent change (AAPC). Results The standardized asthma incidence rate showed a non-significant downward trend and the standardized prevalence rates rose significantly in the three regions. Standardized coronary disease incidence and prevalence rates were considerably higher for men than for women in all regions. The standardized coronary disease incidence rates in Catalonia (AAPC: -8.00%, 95% CI: -10.46; -5.47) and Navarre (AAPC: -3.66%, 95% CI: -4.95;-2.35) showed a significant downward trend from 2007 to 2013, overall and by sex. The standardized coronary disease prevalence trend rate increased significantly in the whole period in Catalonia and the Balearic Islands, although a non-significant downward trend was observed from 2010 in Catalonia. Conclusion No changes in the trends of adult asthma and coronary disease in PHC Spanish patients were detected after the introduction of comprehensive SFL.