Short-term association between air temperature and mortality in seven cities in Norway: A time series analysis.

BACKGROUND: The association between ambient air temperature and mortality has not been assessed in Norway. This study aimed to quantify for seven Norwegian cities (Oslo, Bergen, Stavanger, Drammen, Fredrikstad, Trondheim and Tromsø) the non-accidental, cardiovascular and respiratory diseases mortality burden due to non-optimal ambient temperatures. METHODS: We used a historical daily dataset (1996-2018) to perform city-specific analyses with a distributed lag non-linear model with 14 days of lag, and pooled results in a multivariate meta-regression. We calculated attributable deaths for heat and cold, defined as days with temperatures above and below the city-specific optimum temperature. We further divided temperatures into moderate and extreme using cut-offs at the 1st and 99th percentiles. RESULTS: We observed that 5.3% (95% confidence interval (CI) 2.0-8.3) of the non-accidental related deaths, 11.8% (95% CI 6.4-16.4) of the cardiovascular and 5.9% (95% CI -4.0 to 14.3) of the respiratory were attributable to non-optimal temperatures. Notable variations were found between cities and subgroups stratified by sex and age. The mortality burden related to cold dominated in all three health outcomes (5.1%, 2.0-8.1, 11.4%, 6.0-15.4, and 5.1%, -5.5 to 13.8 respectively). Heat had a more pronounced effect on the burden of respiratory deaths (0.9%, 0.2-1.0). Extreme cold accounted for 0.2% of non-accidental deaths and 0.3% of cardiovascular and respiratory deaths, while extreme heat contributed to 0.2% of non-accidental and to 0.3% of respiratory deaths. CONCLUSIONS: Most of the burden could be attributed to the contribution of moderate cold. This evidence has significant implications for enhancing public-health policies to better address health consequences in the Norwegian setting.

Heat-related cardiorespiratory mortality: Effect modification by air pollution across 482 cities from 24 countries.

BACKGROUND: Evidence on the potential interactive effects of heat and ambient air pollution on cause-specific mortality is inconclusive and limited to selected locations. OBJECTIVES: We investigated the effects of heat on cardiovascular and respiratory mortality and its modification by air pollution during summer months (six consecutive hottest months) in 482 locations across 24 countries. METHODS: Location-specific daily death counts and exposure data (e.g., particulate matter with diameters ≤ 2.5 µm [PM2.5]) were obtained from 2000 to 2018. We used location-specific confounder-adjusted Quasi-Poisson regression with a tensor product between air temperature and the air pollutant. We extracted heat effects at low, medium, and high levels of pollutants, defined as the 5th, 50th, and 95th percentile of the location-specific pollutant concentrations. Country-specific and overall estimates were derived using a random-effects multilevel meta-analytical model. RESULTS: Heat was associated with increased cardiorespiratory mortality. Moreover, the heat effects were modified by elevated levels of all air pollutants in most locations, with stronger effects for respiratory than cardiovascular mortality. For example, the percent increase in respiratory mortality per increase in the 2-day average summer temperature from the 75th to the 99th percentile was 7.7% (95% Confidence Interval [CI] 7.6-7.7), 11.3% (95%CI 11.2-11.3), and 14.3% (95% CI 14.1-14.5) at low, medium, and high levels of PM2.5, respectively. Similarly, cardiovascular mortality increased by 1.6 (95%CI 1.5-1.6), 5.1 (95%CI 5.1-5.2), and 8.7 (95%CI 8.7-8.8) at low, medium, and high levels of O3, respectively. DISCUSSION: We observed considerable modification of the heat effects on cardiovascular and respiratory mortality by elevated levels of air pollutants. Therefore, mitigation measures following the new WHO Air Quality Guidelines are crucial to enhance better health and promote sustainable development.

The burden of hospital-attended influenza in Norwegian children.

Background: Norwegian health authorities do not recommend universal pediatric vaccination against seasonal influenza. We aimed to estimate the incidence of influenza by age and underlying medical conditions in hospitalized Norwegian children aged <18 years. Methods: Active surveillance for influenza in children <18 years was implemented in five hospitals during 2015-18. Children with respiratory symptoms and/or fever were prospectively enrolled and tested for influenza. Surveillance data were linked to health registry data to estimate the national burden of influenza in hospitals. Results: In 309 (10%) out of 3,010 hospital contacts, the child tested positive for influenza, corresponding to an average incidence of 0.96 hospital-attended influenza cases per 1,000 children <18 years of age. Children <1 year of age (3.8 per 1,000 children) and children with underlying medical conditions (17 per 1,000 children with bronchopulmonary dysplasia) had the highest average incidence. Among <1 year old children, 3% tested positive for influenza, compared to 25% for children aged 6-17. Few children were vaccinated against influenza. Conclusions: Children <1 year of age and children with underlying medical conditions had a higher incidence of influenza requiring hospital treatment compared to the general population. Effective interventions against seasonal influenza for children in Norway should be considered.

Cost-effectiveness of Respiratory Syncytial Virus Disease Prevention Strategies: Maternal Vaccine Versus Seasonal or Year-Round Monoclonal Antibody Program in Norwegian Children.

BACKGROUND: Every winter, respiratory syncytial virus (RSV) disease results in thousands of cases in Norwegian children under 5 years of age. We aim to assess the RSV-related economic burden and the cost-effectiveness of upcoming RSV disease prevention strategies including year-round maternal immunization and year-round and seasonal monoclonal antibody (mAb) programs. METHODS: Epidemiological and cost data were obtained from Norwegian national registries, while quality-adjusted life-years (QALYs) lost and intervention characteristics were extracted from literature and phase 3 clinical trials. A static model was used and uncertainty was accounted for probabilistically. Value of information was used to assess decision uncertainty. Extensive scenario analyses were conducted, including accounting for long-term consequences of RSV disease. RESULTS: We estimate an annual average of 13 517 RSV cases and 1572 hospitalizations in children under 5, resulting in 79.6 million Norwegian kroner (~€8 million) treatment costs. At €51 per dose for all programs, a 4-month mAb program for neonates born in November to February is the cost-effective strategy for willingness to pay (WTP) values up to €40 000 per QALY gained. For higher WTP values, the longer 6-month mAb program that immunizes neonates from October to March becomes cost-effective. Sensitivity analyses show that year-round maternal immunization can become a cost-effective strategy if priced lower than mAb. CONCLUSIONS: Assuming the same pricing, seasonal mAb programs are cost-effective over year-round programs in Norway. The timing and duration of the cost-effective seasonal program are sensitive to the pattern of the RSV season in a country, so continued RSV surveillance data are essential.

A Systematic Review of European Clinical Practice Guidelines for Respiratory Syncytial Virus Prophylaxis.

BACKGROUND: Since the widespread adoption of palivizumab prophylaxis in Europe, there have been a number of clinical practice guidelines (CPGs) published for the prevention of respiratory syncytial virus (RSV) infection in children. The aim of this systematic review was to identify CPGs for the prevention of RSV infection across Europe. METHODS: We performed a systematic literature search and contacted European influenza and respiratory virus networks and public health institutions, to identify national CPGs for the prevention of RSV infection. The Reporting Items for practice Guidelines in Healthcare (RIGHT) Statement checklist was applied to extract data and review the quality of reporting. RESULTS: A total of 20 national CPGs were identified, all published between 2000 and 2018. The greatest discrepancy between guidelines was the recommendations for palivizumab prophylaxis for premature infants, with recommendations varying by gestational age. All guidelines recommended or considered the use of palivizumab in infants with bronchopulmonary dysplasia, 85% (n = 17) in children with congenital heart disease (CHD), and 60% (n = 12) in children with severe combined immunodeficiency. CONCLUSIONS: We recommend that agencies publishing RSV prevention guidelines adopt the RIGHT reporting requirements when updating these guidelines to improve the presentation of the evidence-base for decisions.

Respiratory Syncytial Virus-Associated Hospital Admissions and Bed Days in Children <5 Years of Age in 7 European Countries.

BACKGROUND: Respiratory syncytial virus (RSV) is a leading cause of respiratory tract infections (RTIs) in young children. High-quality country-specific estimates of bed days and length of stay (LOS) show the population burden of RSV-RTI on secondary care services and the burden among patients, and can be used to inform RSV immunization implementation decisions. METHODS: We estimated the hospital burden of RSV-associated RTI (RSV-RTI) in children under 5 years in 7 European countries (Finland, Denmark, Norway, Scotland, England, the Netherlands, and Italy) using routinely collected hospital databases during 2001-2018. We described RSV-RTI admission rates during the first year of life by birth month and assessed their correlation with RSV seasonality in 5 of the countries (except for England and Italy). We estimated average annual numbers and rates of bed days for RSV-RTI and other-pathogen RTI, as well as the hospital LOS. RESULTS: We found that infants born 2 months before the peak month of RSV epidemics more frequently had the highest RSV-RTI hospital admission rate. RSV-RTI hospital episodes accounted for 9.9-21.2 bed days per 1000 children aged <5 years annually, with the median (interquartile range) LOS ranging from 2 days (0.5-4 days) to 4 days (2-6 days) between countries. Between 70% and 89% of these bed days were in infants aged <1 year, representing 40.3 (95% confidence interval [CI], 40.1-40.4) to 91.2 (95% CI, 90.6-91.8) bed days per 1000 infants annually. The number of bed days for RSV-RTI was higher than that for RTIs associated with other pathogens in infants aged <1 year, especially in those <6 months. CONCLUSIONS: RSV disease prevention therapies (monoclonal antibodies and maternal vaccines) for infants could help prevent a substantial number of bed days due to RSV-RTI. "High-risk" birth months should be considered when developing RSV immunization schedules. Variation in LOS between countries might reflect differences in hospital care practices.