Burden of Respiratory Syncytial Virus in the European Union: estimation of RSV-associated hospitalizations in children under 5 years.

BACKGROUND: No overall estimate of respiratory syncytial virus (RSV)-associated hospitalizations in children aged under 5 years has been published for the European Union (EU). We aimed to estimate the RSV hospitalization burden in children aged under 5 years in EU countries and Norway, by age group. METHODS: We collated national RSV-associated hospitalization estimates calculated using linear regression models via the RESCEU project for Denmark, England, Finland, Norway, the Netherlands, and Scotland, 2006-2018. Additional estimates were obtained from a systematic review. Using multiple imputation and nearest neighbor matching methods, we estimated overall RSV-associated hospitalizations and rates in the EU. RESULTS: Additional estimates for 2 countries (France and Spain) were found in the literature. In the EU, an average of 245 244 (95% confidence interval [CI], 224 688-265 799) yearly hospital admissions with a respiratory infection per year were associated with RSV in children aged under 5 years, with most cases occurring among children aged under 1 year (75%). Infants aged under 2 months represented the most affected group (71.6 per 1000 children; 95% CI, 66.6-76.6). CONCLUSIONS: Our findings will help support decisions regarding prevention efforts and represent an important benchmark to understand changes in the RSV burden following the introduction of RSV immunization programs in Europe.

Estimation of the Number of Respiratory Syncytial Virus-Associated Hospitalizations in Adults in the European Union.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in adults that can result in hospitalizations. Estimating RSV-associated hospitalization is critical for planning RSV-related healthcare across Europe. METHODS: We gathered RSV-associated hospitalization estimates from the RSV Consortium in Europe (RESCEU) for adults in Denmark, England, Finland, Norway, Netherlands, and Scotland from 2006 to 2017. We extrapolated these estimates to 28 European Union (EU) countries using nearest-neighbor matching, multiple imputations, and 2 sets of 10 indicators. RESULTS: On average, 158 229 (95% confidence interval [CI], 140 865-175 592) RSV-associated hospitalizations occur annually among adults in the EU (≥18 years); 92% of these hospitalizations occur in adults ≥65 years. Among 75-84 years, the annual average is estimated at 74 519 (95% CI, 69 923-79 115) at a rate of 2.24 (95% CI, 2.10-2.38) per 1000. Among ≥85 years, the annual average is estimated at 37 904 (95% CI, 32 444-43 363) at a rate of 2.99 (95% CI, 2.56-3.42). CONCLUSIONS: Our estimates of RSV-associated hospitalizations in adults are the first analysis integrating available data to provide the disease burden across the EU. Importantly, for a condition considered in the past to be primarily a disease of young children, the average annual hospitalization estimate in adults was lower but of a similar magnitude to the estimate in young children (0-4 years): 158 229 (95% CI, 140 865-175 592) versus 245 244 (95% CI, 224 688-265 799).

Migrant GPs and patients: a cross-sectional study of practice characteristics, patient experiences and migration concordance.

OBJECTIVE: To investigate practice type and location of native and immigrant general practitioners (GPs); effects of migration status concordance between GPs and patients on experiences of patients in key areas of primary care quality and discrimination. DESIGN AND SETTING: Secondary analysis of GP and patient survey data from QUALICOPC (Quality and Costs of Primary Care), a cross-sectional study of GPs and their patients in 34 countries, performed between 2011 and 2013. MAIN OUTCOME MEASURES: We explored practice type and location of native and immigrant GPs and the experiences of native patients and patients with a migration background of communication, continuity, comprehensiveness, accessibility, and discrimination, using multilevel analysis. Concordance was modelled as a cross-level interaction between migration status of GPs and patients. RESULTS: Percentages of immigrant GPs varied widely. In Europe, this was highest in England and Luxemburg (40% of GPs born abroad) and lowest in Bulgaria and Romania (1%). The practice population of immigrant GPs more often included an above average proportion of people from ethnic minorities. There were no differences in main effects of patient experiences following a visit to an immigrant or native GP, in four core areas of primary care or in discrimination. However, people from first-generation migrant background more often experienced discrimination, in particular when visiting a native GP. CONCLUSION: Patient experiences did not vary with GPs' migration status. Although experience of discrimination was uncommon, first-generation migrant patients experienced more discrimination. Primary care should provide non-discriminatory care, through GP awareness of unconscious bias and training to address this. Key messagesThere were large differences in percentage of migrant GPs between countries.Migrant GPs' practices had an above average proportion of people from ethnic minorities.In general, patients' experienced discrimination from GPs and practice staff was low, but first-generation migrant patients more often experienced discrimination.First-generation migrant patients more often experienced discrimination when they visited a native GP.

The Turkish version of the SPPIC validated among informal caregivers with a Turkish immigrant background.

BACKGROUND: This study assesses the internal consistency and known group validity of the Turkish version of the SPPIC, a measurement instrument to assess the self perceived pressure from informal care in family caregivers of people with dementia that was originally in Dutch. METHODS: The feasibility, comprehensibility and appropriateness of the Turkish SPPIC were assessed during a pilot test. Internal consistency was examined based on data from 117 family caregivers with a Turkish immigrant background by calculating Cronbach's alpha and by conducting a single-factor Confirmatory Factor Analysis (CFA). Known group validity was determined to obtain an understanding of the validity of the translated instrument, testing differences in the self-perceived pressure from informal care, depending on frequency of caregiving, living with a person with dementia and level of education. RESULTS: The pilot test showed that the translated SPPIC was considered to be feasible, comprehensible and appropriate. The internal consistency appeared to be strong (Cronbach's alpha: 0.94). The CFA indicated that the factor 'Self-perceived Pressure from Informal Care' explained varying levels of variance in the items of the SPPIC (ranging from .52 to .87). Family caregivers who provided care at least once a week and who shared a home with a person with dementia perceived a greater pressure from informal care (p = 0.007, p = 0.001). CONCLUSIONS: The Turkish translation of the SPPIC can be used in future research and practice to obtain insight into self-perceived pressure from informal care of family caregivers with Turkish immigrant backgrounds. At the same time it is recommended to conduct more research on how the measurement of self-perceived pressure from informal care in this group can be further improved.

Immediate and long-term health impact of exposure to gas-mining induced earthquakes and related environmental stressors.

BACKGROUND: Little is known about the public health impact of chronic exposure to physical and social stressors in the human environment. Objective of this study was to investigate the immediate and long-term health effects of living in an environment with gas-mining induced earthquakes and related stressors in the Netherlands. METHODS: Data on psychological, somatic and social problems recorded routinely in electronic health records by general practitioners during a 6-year period (2010-2015) were combined with socioeconomic status and seismicity data. To assess immediate health effects of exposure to ML≥1.5 earthquakes, relative risk ratios were calculated for patients in the week of an earthquake and the week afterwards, and compared to the week before the earthquake. To analyse long-term health effects, relative risks of different groups, adjusted for age, sex and socioeconomic status, were computed per year and compared. RESULTS: Apart from an increase in suicidality, few immediate health changes were found in an earthquake week or week afterwards. Generally, the prevalence of health problems was higher in the mining province in the first years, but dropped to levels equal to or even below the control group in subsequent years, with lower relative risks observed in more frequently exposed patients. CONCLUSIONS: From a public health perspective, the findings are fascinating. Contrary to our expectation, health problems presented in general practice in the earthquake province decreased during the study period. More frequently exposed populations reported fewer health issues to general practitioners, which might point at health adaptation to chronic exposure to stressors.

Physical accessibility of primary care facilities for people with disabilities: a cross-sectional survey in 31 countries.

BACKGROUND: Primary care is the first point of care, also for people with disabilities. The accessibility of primary care facilities is therefore very important. In this study we analysed comparative data on physical accessibility of general practices (GP practices) in 31 (mainly) European countries. METHODS: We used data from the QUALICOPC study, conducted in 2011 among GPs in 34 (mainly European) countries and constructed a physical accessibility scale. We applied multilevel analysis to assess the differences between and within countries and to test hypotheses, related to characteristics of the practices and of the countries. RESULTS: We found large differences between countries and a strong clustering of physical accessibility within countries. Physical accessibility was negatively related to the age of the GPs, and was less in single-handed and in inner city practices. Of the country variables only the length of the period of social democratic government participation during the previous decades was positively related to physical accessibility. CONCLUSION: A large share of the variation in physical accessibility of GP practices was on the level of countries. This means that national policies can be used to increase physical accessibility of GP practices.

Exploring the impact of patient and public involvement with young people with a chronic condition: A multilevel analysis.

BACKGROUND: Patient and Public Involvement (PPI) of young people with a chronic condition (YPCC) receives increasing attention. However, evidence of its impact is lacking. This study explores the impact of PPI on outcomes of projects in health and social care, using quantitative measures. METHODS: Data were collected from projects funded by a 4-year participatory program addressing the social position of YPCC. These projects addressed challenges associated with, for example, going to college with a physical disability, transitions in care and finding a job. Project coordinators filled out project reports with questions about PPI, that is, to what extent were YPCC involved, were they involved as co-deciders and were they involved in developing the project idea. YPCC filled out questionnaires with questions about PPI, that is, the number of PPI activities and self-perceived importance for the project. They also answered questions about the influence of the project on their social position. Based on these questions, a project outcome scale was developed. RESULTS: The data concerned 17 projects and 146 YPCC. Variation existed in project outcomes, of which 27% was associated with differences between projects. Using multilevel analyses, a significant relation was found between the self-perceived importance of YPCC for the project and the project outcomes they experience (0.232, p < 0.01). There was no significant association with the other PPI variables. CONCLUSIONS: This study provided some first quantitative evidence that PPI has a positive impact on the YPCC involved. It is suggested that the meaningfulness of PPI matters more to them than the number of activities and amount of influence provided to YPCC. We strongly recommend conducting more research that critically examines impact of PPI.

The primary care workforce in Europe: a cross-sectional international comparison of rural and urban areas and changes between 1993 and 2011.

Rural areas have problems in attracting and retaining primary care workforce. This might have consequences for the existing workforce. We studied whether general practitioners (GPs) in rural practices differ by age, sex, practice population and workload from those in less rural locations and whether their practices differ in resources and service profiles. We used data from 2 studies: QUALICOPC study collected data from 34 countries, including 7183 GPs in 2011, and Profiles of General Practice in Europe study collected data from 32 countries among 7895 GPs in 1993. Data were analyzed using multilevel analysis. Results show that the share of female GPs has increased in rural areas but is still lower than in urban areas. In rural areas, GPs work more hours and provide more medical procedures to their patients. Apart from these differences between locations, overall ageing of the GP population is evident. Higher workload in rural areas may be related to increased demand for care. Rural practices seem to cope by offering a broad range of services, such as medical procedures. Dedicated human resource policies for rural areas are required with a view to an ageing GP population, to the individual preferences and needs of the GPs, and to decreasing attractiveness of rural areas.

Communication between general practitioners and medical specialists in the referral process: a cross-sectional survey in 34 countries.

BACKGROUND: The communication of relevant patient information between general practitioners (GPs) and medical specialists is important in order to avoid fragmentation of care thus achieving a higher quality of care and ensuring physicians' and patients' satisfaction. However, this communication is often not carried out properly. The objective of this study is to assess whether communication between GPs and medical specialists in the referral process is associated with the organisation of primary care within a country, the characteristics of the GPs, and the characteristics of the primary care practices themselves. METHODS: An analysis of a cross-sectional survey among GPs in 34 countries was conducted. The odds ratios of the features that were expected to relate to higher rates of referral letters sent and communications fed back to GPs were calculated using ordered logistic multilevel models. RESULTS: A total of 7183 GPs from 34 countries were surveyed. Variations between countries in referral letters sent and feedback communication received did occur. Little of the variance between countries could be explained. GPs stated that they send more referral letters, and receive more feedback communications from medical specialists, in countries where they act as gatekeepers, and when, in general, they interact more with specialists. GPs reported higher use of referral letters when they had a secretary and/or a nurse in their practice, used health information technologies, and had greater job satisfaction. CONCLUSIONS: There are large differences in communication between GPs and medical specialists. These differences can partly be explained by characteristics of the country, the GP and the primary care practice. Further studies should also take the organisation of secondary care into account.

Using web search queries to monitor influenza-like illness: an exploratory retrospective analysis, Netherlands, 2017/18 influenza season.

BackgroundDespite the early development of Google Flu Trends in 2009, standards for digital epidemiology methods have not been established and research from European countries is scarce.AimIn this article, we study the use of web search queries to monitor influenza-like illness (ILI) rates in the Netherlands in real time.MethodsIn this retrospective analysis, we simulated the weekly use of a prediction model for estimating the then-current ILI incidence across the 2017/18 influenza season solely based on Google search query data. We used weekly ILI data as reported to The European Surveillance System (TESSY)  each week, and we removed the then-last 4 weeks from our dataset. We then fitted a prediction model based on the then-most-recent search query data from Google Trends to fill the 4-week gap ('Nowcasting'). Lasso regression, in combination with cross-validation, was applied to select predictors and to fit the 52 models, one for each week of the season.ResultsThe models provided accurate predictions with a mean and maximum absolute error of 1.40 (95% confidence interval: 1.09-1.75) and 6.36 per 10,000 population. The onset, peak and end of the epidemic were predicted with an error of 1, 3 and 2 weeks, respectively. The number of search terms retained as predictors ranged from three to five, with one keyword, 'griep' ('flu'), having the most weight in all models.DiscussionThis study demonstrates the feasibility of accurate, real-time ILI incidence predictions in the Netherlands using Google search query data.

Exploring patient-centered aspects of home care communication: a cross-sectional study.

BACKGROUND: Communication is a cornerstone in nursing and aims at both information exchange and relationship building. To date, little is known about the naturally occurring communication between older persons and nurses in home care. Communication might heal through different pathways and a patient- or person-centered communication could be important for health and well-being of older persons. However, the delivery of individualized home care is challenged by routines and organizational demands such as time constraints. Therefore, the aim of this study was to explore the patient-centered aspects of home care communication between older persons and registered nurses. METHODS: In total 37 older persons (aged 65 years or older) and eleven RNs participated in 50 audio-recorded home care visits. Roter Interaction Analysis System (RIAS) was used to code verbal communication. A ratio from these codes, establishing the degree of patient-centeredness, was analyzed using a Generalized Linear Mixed Model. RESULTS: The present home care communication contained more socio-emotional than task-oriented communication and the emotional tone was largely positive. The global affect ratings reflected an overall positive tone (m = 39.88, sd = 7.65), with higher ratings on dimensions of, for example, responsiveness/engagement and interactivity or interest were more frequent than those that may be considered as less-positive emotions (m = 15.56, sd = 3.91), e.g. hurried, dominance or anger. The ratio of the degree of patient-centered communication in the home care visits was an average of 1.53, revealing that the communication could be considered as patient-centered. The length of the visits was the only characteristic significantly associated with the degree of patient-centeredness in the communication, with a peak in patient-centeredness in visits 8-9 min long. Sex, age or procedural focus showed no significant effects on the degree of patient-centeredness. CONCLUSION: Overall, the degree of patient-centeredness and a positive emotional tone, which might have a positive outcome on older persons' health, was high. Longer visits provided a higher degree of patient-centeredness, but no linear increase in patient-centeredness due to length of visit could be observed. The findings can be used for education and training of nurses, and for providing individualized care, e.g. patient- or person-centered care.

Shared decision-making in general practice: an observational study comparing 2007 with 2015.

BACKGROUND: Shared decision-making (SDM) is, largely, espoused as the preferred model for making decisions in everyday health care. Studies exploring the application of SDM in primary care practice are still lacking. OBJECTIVES: This study explores how GPs involve their patients in decision-making, if application of SDM has increased over time (2007-15), and what factors are associated with it. METHODS: We investigated the application of SDM by Dutch GPs by analysing a random set of real-life video-recorded consultations collected in 2007 (n = 50) and 2015 (n = 50). SDM was assessed by observing patient involvement in decision making (OPTION), a reliable and valid instrument measuring the extent to which clinicians involve patients in decision-making by coding 12 behavioural items. In addition, GPs and patients completed questionnaires about their background characteristics. The potential determinants for application of SDM by Dutch GPs (including year of measurement, sex and age of patients and GPs, the nature of complaints, consultation duration and the type of decision discussed) were analysed using multilevel analysis [with patients (Level 1) nested within GPs (Level 2)]. RESULTS: In 2015, GPs applied SDM more often compared with 2007 according to OPTION. In consultations with older patients, there is less application of SDM by GPs. CONCLUSIONS: Although application of SDM by Dutch GPs has increased, low overall SDM scores still leave room for improvement. GPs should elicit the patient's preferred role in the decision-making process at any time, in particular in consultations with older patients.

Citizens' initiatives for care and welfare in the Netherlands: an ecological analysis.

BACKGROUND: In the Netherlands as well as in other countries citizens take initiatives to provide or maintain services in the area of care and welfare. Citizens' initiatives (CI's) are organisations some of which have a formal structure while others are informally connected groups of citizens, that are established by a group of citizens with the aim to increase the health and welfare within their local community and that are not focused on making a profit. Although CI's have been around since at least the 1970's little research has been done on the phenomenon, with most of it consisting of case studies or qualitative exploratory research. To fill part of this gap in knowledge, we have studied the geographical variation in the presence of CI's in the Netherlands and tried to explain this variation. METHODS: Data on the presence of CI's were obtained by combining two existing inventories. We did an ecological regression analysis to test hypotheses about the relationship between the presence of CI's and the existence of a care vacuum, the capacity for self-organisation and models of action in local communities. RESULTS: We counted 452 CI's in care and welfare in the Netherlands in January 2016. Our results show a spatial concentration of care initiatives in urban areas in the Randstad cities in the west of the country and in rural areas in the south-east. The presence of CI's is only weakly associated with a care vacuum, but is related to indicators for the capacity of concerted action and models of action. CONCLUSION: There are by now a considerable number of CI's in the area of care and welfare in the Netherlands. Apparently, citizens take collective initiatives to provide services that are not, or no longer, available to the local community. The initiatives are concentrated in certain parts of the country. However, our theoretical model to explain this geographical pattern is only partially confirmed.

Patients' perception of communication at the interface between primary and secondary care: a cross-sectional survey in 34 countries.

BACKGROUND: Poor communication between general practitioners (GPs) and medical specialists can lead to poorer quality, and continuity, of care. Our study aims to assess patients' perceptions of communication at the interface between primary and secondary care in 34 countries. It will analyse, too, whether this communication is associated with the organisation of primary care within a country, and with the characteristics of GPs and their patients. METHODS: We conducted a cross-sectional survey among patients in 34 countries. Following a GP consultation, patients were asked two questions. Did they take to understand that their GP had informed medical specialists about their illness upon referral? And, secondly, did their GP know the results of the treatment by a medical specialist? We used multi-response logistic multilevel models to investigate the association of factors related to primary care, the GP, and the patient, with the patients' perceptions of communication at the interface between primary and secondary care. RESULTS: In total, 61,931 patients completed the questionnaire. We found large differences between countries, in both the patients' perceptions of information shared by GPs with medical specialists, and the patients' perceptions of the GPs' awareness of the results of treatment by medical specialists. Patients whose GPs stated that they 'seldom or never' send referral letters, also less frequently perceived that their GP communicated with their medical specialists about their illness. Patients with GPs indicating they 'seldom or never' receive feedback from medical specialists, indicated less frequently that their GP would know the results of treatment by a medical specialist. Moreover, patients with a personal doctor perceived higher rates of communication in both directions at the interface between primary and secondary care. CONCLUSION: Generally, patients perceive there to be high rates of communication at the interface between primary and secondary care, but there are large differences between countries. Policies aimed at stimulating personal doctor arrangements could, potentially, enhance the continuity of care between primary and secondary care.

Interruptions during intravenous medication administration: A multicentre observational study.

AIMS: The aim of this study was to determine the frequency and cause of interruptions during intravenous medication administration, which factors are associated with interruptions and to what extent interruptions influence protocol compliance. BACKGROUND: Hospital nurses are frequently interrupted during medication administration, which contributes to the occurrence of administration errors. Errors with intravenous medication are especially worrisome, given their immediate therapeutic effects. However, knowledge about the extent and type of interruptions during intravenous medication administration is limited. DESIGN: Multicentre observational study. METHODS: Data were collected during two national evaluation studies (2011 - 2012 & 2015 - 2016). Nurses were directly observed during intravenous medication administration. An interruption was defined as a situation where a break during the administration was needed or where a nurse was distracted but could process without a break. Interruptions were categorized according to source and cause. Multilevel logistic regression analyses were conducted to assess the associations between explanatory variables and interruptions or complete protocol compliance. RESULTS: In total, 2,526 intravenous medication administration processes were observed. During 291 (12%) observations, nurses were interrupted 321 times. Most interruptions were externally initiated by other nurses (19%) or patients (19%). Less interruptions occurred during the evening (odds ratio: 0.23 [95% confidence interval: 0.08-0.62]). Do-not-disturb vests were worn by 61 (2%) nurses. No significant association was found between being interrupted and complete protocol compliance. CONCLUSION: An interruption occurred in every eight observed intravenous medication administration, mainly caused by other nurses or patients. One needs to consider critically which strategies effectively improve safety during the high-risk nursing-task of intravenous medication administration.

Emotional communication with older people: A cross-sectional study of home care.

The aim of this study was to explore the influence of characteristics of nurses and older people on emotional communication in home care settings. A generalized, linear, mixed model was used to analyze 188 audio-recorded home care visits coded with Verona Coding Definitions of Emotional Sequences. The results showed that most emotional distress was expressed by older females or with female nurses. The elicitation of an expression of emotional distress was influenced by the nurses' native language and profession. Older women aged 65-84 years were given the most space for emotional expression. We found that emotional communication was primarily influenced by sex for nurses and older people, with an impact on the frequency of expressions of and responses to emotional distress. Expressions of emotional distress by older males were less common and could risk being missed in communication. The results have implications for students' and health professionals' education in increasing their knowledge of and attentiveness to the impacts of their and others' characteristics and stereotypes on emotional communication with older people.

Reassessing the Global Mortality Burden of the 1918 Influenza Pandemic.

Mortality estimates of the 1918 influenza pandemic vary considerably, and recent estimates have suggested that there were 50 million to 100 million deaths worldwide. We investigated the global mortality burden using an indirect estimation approach and 2 publicly available data sets: the Human Mortality Database (13 countries) and data extracted from the records of the Statistical Abstract for British India. The all-cause Human Mortality Database was used to estimate mortality annually for 1916-1921 for detailed age groups. Three different calculation methods were applied to the data (low, medium, and high scenarios), and we used a multilevel regression model to control for distorting factors (e.g., war and the underlying time trend in mortality). Total pandemic mortality was an estimated 15 million deaths worldwide in 1918 (n = 2.5 million in 1919) after including the rates for British India and controlling for wars and the underlying mortality trend. According to our validity analysis, simulations of total number of deaths being greater than 25 million are not realistic based on the underlying mortality rates included in Human Mortality Database and in British India. Our results suggest the global death impact of the 1918 pandemic was important (n = 17.4 million) but not as severe as most frequently cited estimates.

Distribution of serotypes and patterns of antimicrobial resistance among commensal Streptococcus pneumoniae in nine European countries.

BACKGROUND: Streptococcus pneumoniae is a commensal of the human upper respiratory tract and a major cause of morbidity and mortality worldwide. This paper presents the distribution of serotypes and antimicrobial resistance in commensal S. pneumoniae strains cultured from healthy carriers older than four years of age in nine European countries. METHODS: Nasal swabs from healthy persons (age between 4 and 107 years old) were obtained by general practitioners from each country from November 2010 to August 2011. Swabs were cultured for S. pneumoniae using a standardized protocol. Antibiotic resistance was determined for isolated S. pneumoniae by broth microdilution. Capsular sequencing typing was used to identify serotypes, followed by serotype-specific PCR assays in case of ambiguous results. RESULTS: Thirty-two thousand one hundred sixty-one nasal swabs were collected from which 937 S. pneumoniae were isolated. A large variation in serotype distribution and antimicrobial resistant serotypes across the participating countries was observed. Pneumococcal vaccination was associated with a higher risk of pneumococcal colonization and antimicrobial resistance independently of country and vaccine used, either conjugate vaccine or PPV 23). CONCLUSIONS: Serotype 11A was the most common in carriage followed by serotypes 23A and 19A. The serotypes showing the highest resistance to penicillin were 14 followed by 19A. Serotype 15A showed the highest proportion of multidrug resistance.

Distribution of influenza virus types by age using case-based global surveillance data from twenty-nine countries, 1999-2014.

BACKGROUND: Influenza disease burden varies by age and this has important public health implications. We compared the proportional distribution of different influenza virus types within age strata using surveillance data from twenty-nine countries during 1999-2014 (N=358,796 influenza cases). METHODS: For each virus, we calculated a Relative Illness Ratio (defined as the ratio of the percentage of cases in an age group to the percentage of the country population in the same age group) for young children (0-4 years), older children (5-17 years), young adults (18-39 years), older adults (40-64 years), and the elderly (65+ years). We used random-effects meta-analysis models to obtain summary relative illness ratios (sRIRs), and conducted meta-regression and sub-group analyses to explore causes of between-estimates heterogeneity. RESULTS: The influenza virus with highest sRIR was A(H1N1) for young children, B for older children, A(H1N1)pdm2009 for adults, and (A(H3N2) for the elderly. As expected, considering the diverse nature of the national surveillance datasets included in our analysis, between-estimates heterogeneity was high (I2>90%) for most sRIRs. The variations of countries' geographic, demographic and economic characteristics and the proportion of outpatients among reported influenza cases explained only part of the heterogeneity, suggesting that multiple factors were at play. CONCLUSIONS: These results highlight the importance of presenting burden of disease estimates by age group and virus (sub)type.

Climatic factors and long-term trends of influenza-like illness rates in The Netherlands, 1970-2016.

BACKGROUND: Climatic factors affect the survival and transmissibility of respiratory viruses causing influenza-like illness (ILI), and we hypothesized that changes in absolute humidity and temperature may affect long-term trends of ILI incidence rate in temperate countries. We tested this hypothesis using ILI and meteorological time series in the Netherlands for the period 1970-2016. METHODS: We described the long-term trends of ILI incidence, absolute humidity and temperature; modelled the association between climatic factors and ILI activity using negative binomial regression models; and assessed the strength of the association between the seasonal average absolute humidity (or temperature) and ILI incidence rate using the Spearman's rank correlation coefficient. RESULTS: The ILI incidence rate declined from 1970 and reached a minimum in the season 2002-03, but started to increase again from the season 2003-04 onwards. In the negative binominal regression models, the weekly ILI count was inversely associated (p < 0.001) with 0- and 1-week lagged absolute humidity and temperature. After three decades of rising absolute humidity and temperature (1970-2000), the early 2000s represented a trend-reversal point for the climatic time series. The seasonal average ILI incidence rate and absolute humidity (or temperature) were strongly (inversely) correlated. CONCLUSIONS: Our findings suggest that climate change may have played a role in the long-term trends of ILI incidence rates in the Netherlands, as we were able to show that lower humidity and temperature in a given week were associated with higher ILI incidence in the next week, there was a clear time point reversal in climatic parameters and ILI rates in the 2000s, and the average annual ILI incidence was inversely related to average annual temperatures and humidity.