Respiratory-related Hospital Admissions Research Articles

Respiratory Health Inequities among Children and Young Adults with Cerebral Palsy in Aotearoa New Zealand: A Data Linkage Study.

(1) Background: Respiratory disease is a leading cause of morbidity, mortality, and poor quality of life in children with cerebral palsy (CP). This study describes the prevalence of CP-related respiratory disease and the non-modifiable risk factors for respiratory-related hospital admissions in the Aotearoa New Zealand population. (2) Methods: New Zealand Cerebral Palsy Register (NZCPR) participant data and de-identified data from the National Minimum Dataset and Pharmaceutical Dispensing Collections were linked to identify all respiratory-related hospital admissions and respiratory illness-related antibiotic exposure over 5 years in individuals with CP (0−26 years). (3) Results: Risk factors for respiratory-related hospital admissions included being classified Gross Motor Function Classification System (GMFCS) IV or V compared to GMFCS I [OR = 4.37 (2.90−6.58), p < 0.0001; OR = 11.8 (7.69−18.10), p < 0.0001, respectively,]; having ≥2 antibiotics dispensed per year [OR = 4.42 (3.01−6.48), p < 0.0001]; and being of Māori ethnicity [OR = 1.47 (1.13−1.93), p < 0.0047]. Māori experienced health inequities compared to non-Māori, with greater functional disability, and also experienced greater antibiotic dispensing than the general population. (4) Conclusion: Māori children and young adults have a higher risk of respiratory-related illness. Priority should be given to the screening for potentially modifiable risk factors for all children with CP from diagnosis onwards in a way that ensures Māori health equity.

253 Economic burden of care and treatment options for Rett syndrome: two systematic literature reviews

Rett syndrome, a rare disorder caused by MECP2 mutation, causes severe developmental impairment in afflicted girls. We performed two literature reviews in June 2018 to assess Rett syndrome clinical trials (MEDLINE/Embase/ClinicalTrials.gov/Cochrane Library) and the economic burden of care (Medline/Embase/Cochrane Library/Database of Abstracts of Reviews and Effects). The economic burden search yielded 133 articles; intervention type/costs were extracted from 9, representing 4 studies. Enteral feeding/assisted walking increased the risk of respiratory-related hospital admissions, while length-of-stay was lower in younger patients. Mean recovery-stay after scoliosis-correcting surgery was 18.2/12.3 days in each of two studies. Care integration improved outcomes and reduced costs. The clinical trials search yielded 652 articles; efficacy/safety were extracted from 28, representing 20 studies (15 randomized controlled trials, 5 single-arm; N=8–82; follow-up 1–26 months). Nineteen focused on pharmacological symptom treatment; 1 examined environmental enrichment effects; most common primary endpoints: Rett syndrome Gross Motor Scale, Clinical Severity Score, Motor and Behavioral Assessment, and the Anxiety Depression and Mood Scale. Naltrexone, trofinetide, and mecasermin demonstrated clinical benefits, but most treat- ments yielded no significant improvement. Clinical practice guidelines and treatment patterns data were limited. There is demand for treatments targeting the underlying cause, such as gene therapy. Previously presented after 08/2019.jloukes879@avexis.com158

Self-management interventions for people with chronic obstructive pulmonary disease.

Self-management interventions for people with chronic obstructive pulmonary disease.

Intermittent prophylactic antibiotics for bronchiectasis.

Intermittent prophylactic antibiotics for bronchiectasis.

Tailored or adapted interventions for adults with chronic obstructive pulmonary disease and at least one other long-term condition: a mixed methods review.

Tailored or adapted interventions for adults with chronic obstructive pulmonary disease and at least one other long-term condition: a mixed methods review.

Neighborhood Disadvantage and Early Respiratory Outcomes in Very Preterm Infants with Bronchopulmonary Dysplasia

To investigate the impact of neighborhood conditions on respiratory-related hospital admissions in the first year after discharge from the neonatal unit in a population of infants born very preterm with bronchopulmonary dysplasia (BPD). Very preterm infants (gestational age <33 weeks) who had BPD at 36 weeks postconceptional age and who received follow-up in a French regional medical network were included. Socioeconomic context was estimated using a neighborhood-based Socioeconomic Deprivation Index. Poisson regression analysis was used to identify risk factors associated with rehospitalization. The study included 423 infants with a mean gestational age of 27 ± 2 weeks and mean birth weight of 941 ± 277 g; 51% of the population lived in a disadvantaged area. The hospital admission rate was increased by 8.8% for infants living in affluent areas and by 24% for those living in disadvantaged areas (P<.01) and reached 30% in extremely preterm infants from disadvantaged areas. After adjusting for perinatal characteristics, home oxygen therapy, and season of birth, the respiratory-related hospitalization rate was almost 3-fold higher in infants living in disadvantaged areas, with an adjusted incidence rate ratio of 2.79 (95% CI, 1.29-6.09; P <.01). Disadvantaged neighborhoods adversely impact early respiratory outcomes in infants born very preterm with BPD. The social context should be considered in routine follow-up care of children born preterm. Further studies investigating the underlying mechanisms are warranted for implementing preventive strategies.

Predictors of home oxygen duration in chronic neonatal lung disease.

In infants with chronic neonatal lung disease (CNLD), we aimed to identify predictors of home oxygen duration, predictors of discharge oxygen flow rates, and the association of oxygen flow rates with respiratory outcomes. Infants with CNLD requiring home oxygen in 2016 and 2017 were retrospectively reviewed. Hazard ratios (HR) were estimated from Cox proportional hazards regression models in the cohort. A multinomial logistic regression model examined the effects of maternal and infant variables on discharge oxygen flow rates. Kruskal-Wallis test with univariate linear regression and Fisher's exact test with binomial univariate logistic regression were used to examine associations between oxygen flow groups and post-discharge clinical variables. One hundred and forty-nineinfants were included. Median corrected gestational age (CGA) at oxygen cessation was 6.8 months (interquartile range, 4.4) with 87.2% of infants weaned by 12 months CGA. Shorter initial neonatal intensive care unit (NICU) stay predicted faster oxygen weaning at 9 months (HR, 0.99; 95% confidence interval [CI], 0.98-1.00, p = .02) and 12 months (HR, 0.99; 95% CI, 0.98-1.00, p = .02). Infants with hypercarbia at discharge or discharged from NICU at higher CGA had higher odds of requiring ≥ 200 ml/min relative to ≤ 125 ml/min oxygen. Infants discharged with > 250 ml/min oxygen were more likely to have a respiratory-related admission before 2 years chronological age. Shorter initial NICU stay was the best predictor of earlier home oxygen cessation. At NICU discharge, infants with hypercarbia or a higher CGA may require more home oxygen and experience more respiratory-related hospital admission in the first 2 years of chronological age.

Association of short-term exposure to ambient PM2.5 with hospital admissions and 30-day readmissions in end-stage renal disease patients: population-based retrospective cohort study

ObjectivesTo examine the effect of short-term exposure to ambient fine particulate matter (PM2.5) on all-cause, cardiovascular and respiratory-related hospital admissions and readmissions among patients receiving outpatient haemodialysis.DesignRetrospective cohort study.SettingInpatient hospitalisation...

Decrease in Respiratory Related Hospitalizations in Tracheostomy-Dependent Children Who Tolerate Passy-Muir Valve Use.

To assess the effect of Passy-Muir® Valve (PMV) tolerance on respiratory illness and respiratory related hospital admissions in tracheostomy-dependent children. Retrospective cohort study of 262 patients who underwent tracheostomy placement between 2012 and 2018 at a tertiary free-standing children's hospital. Outcome measures studied were number of reported upper respiratory infections and respiratory related hospitalizations per year (RRH/year). About 135 (51.5%) tracheostomy-dependent children underwent PMV trials, and 106 (78.5%) of these children were able to tolerate PMV for at least 1 hour daily. When comparing children who tolerated PMV versus those who did not, the latter group had significantly higher rates of subglottic stenosis but no significant differences in RRH/year or average age. In those children who tolerated PMV and achieved routine use of PMV > 1 hour/day, an average of 1.14 RRH/year occurred prior to PMV tolerance, as compared with 0.57 RRH/year after PMV tolerance (P = .003). Multivariate analysis shows that in patients <2 years, there is a significant decrease in RRH/year after PMV tolerance is attained (1.53 vs 0.76, P = .001), independent of indication for tracheostomy. In tracheostomy-dependent children who tolerate PMV use routinely >1 hour/day there are decreased rates of respiratory related hospitalizations (RRH). Children <2 years of age have the most impact of RRH, with rates that are significantly lower with routine use of the PMV.

Long-term prognosis of new adult-onset asthma in obese patients.

BackgroundObesity has been associated with poor outcomes of asthma in cross-sectional studies, but long-term effect of obesity on asthma remains unknown.AimsTo study the effects of obesity, found at the time of diagnosis of adult-onset asthma, on 12-year prognosis by focusing on oral corticosteroid (OCS) use and respiratory-related hospital admissions.MethodsPatients diagnosed with adult-onset asthma (n=203) were divided into three categories based on diagnostic body mass index (BMI) (<25 kg·m−2, 25–29.9 kg·m−2, ≥30 kg·m−2) and followed for 12 years as part of the Seinäjoki Adult Asthma Study. Self-reported and dispensed OCS were assessed for the 12-year period. Data on hospital admissions were analysed based on medical records.Results12 years after diagnosis, 86% of the patients who were obese (BMI ≥30 kg·m−2) at diagnosis remained obese. During the follow-up, no difference was found in weight gain between the BMI categories. During the 12-year follow-up, patients obese at diagnosis reported more frequent use of OCS courses (46.9% versus 23.1%, p=0.028), were dispensed OCS more often (81.6% versus 56.9%, p=0.014) and at higher doses (median 1350 (interquartile range 280–3180) mg versus 600 (0–1650) mg prednisolone, p=0.010) compared to normal-weight patients. Furthermore, patients who were obese had more often one or more respiratory-related hospitalisations compared to normal-weight patients (38.8% versus 16.9%, p=0.033). In multivariate logistic regression analyses, obesity predicted OCS use and hospital admissions.ConclusionsIn adult-onset asthma, patients obese at diagnosis mostly remained obese at long-term and had more exacerbations and respiratory-related hospital admissions compared to normal-weight patients during 12-year follow-up. Weight loss should be a priority in their treatment to prevent this outcome.

Hospital Admission Trends for Bronchiolitis in Scotland, 2001-2016: A National Retrospective Observational Study.

Bronchiolitis is the commonest cause of respiratory related hospital admissions in young children. This study aimed to describe temporal trends in bronchiolitis admissions for children under 2 years of age in Scotland by patient characteristics, socioeconomic deprivation, and duration of admission. The national hospital admissions database for Scotland was used to extract data on all bronchiolitis admissions (International Classification of Disease, Tenth Revision, code J21) in children <2 years of age from 2001 to 2016. Deprivation quintiles were classified using the 2011 Scottish Index of Multiple Deprivation. Over the 15-year study period, admission rates for children under 2 years old increased 2.20-fold (95% confidence interval [CI], 1.4-3.6-fold) from 17.2 (15.9-18.5) to 37.7 (37.4-38.1) admissions per 1000 children per year. Admissions peaked in infants aged 1 month, and in those born in the 3 months preceding the peak bronchiolitis month-September, October, and November. Admissions from the most-deprived quintile had the highest overall rate of admission, at 40.5 per 1000 children per year (95% CI, 39.5-41.5) compared with the least-deprived quintile, at 23.0 admissions per 1000 children per year (22.1-23.9). The most-deprived quintile had the greatest increase in admissions over time, whereas the least-deprived quintile had the lowest increase. Zero-day admissions, defined as admission and discharge within the same calendar date, increased 5.3-fold (5.1-5.5) over the study period, with the highest increase in patients in the most-deprived quintile. This study provides baseline epidemiological data to aid policy makers in the strategic planning of preventative interventions. With the majority of bronchiolitis caused by respiratory syncytial virus (RSV), and several RSV vaccines and monoclonal antibodies currently in clinical trials, understanding national trends in bronchiolitis admissions is an important proxy for determining potential RSV vaccination strategies.

Respiratory illness, hospital visits, and health costs: Is it air pollution or pollen?

BackgroundBoth air pollution and airborne pollen can cause respiratory health problems. Since both are often jointly present in ambient air, it is important to control for one while estimating the effect of the other when considering pollution-abating policies. To date only a limited number of studies have considered the health effects of both irritants jointly for a general population, and for a sufficiently long time period to allow for variation in seasonal concentrations of both components. The primary goal of this study is to determine the causal impact of fine particulate matter (PM2.5) on hospital visits and related treatment costs, while controlling for potentially confounding pollen effects. Our study area is the metropolitan hub of Reno/Sparks in Northern Nevada. MethodsTaking advantage of a rare sample of daily pollen counts over a prolonged period of time (2009–2015), we model the effects of PM2.5 and pollen on respiratory-related hospital admissions for the population at large, plus specific age groups. Pollen data are provided by a local allergy clinic. Data on PM2.5 and other air pollutants are obtained from the U.S. Environmental Protection Agency's air quality data web site. We collect daily meteorological data from the National Centers for Environmental Information's data repository. Data on hospital admissions are given by the Nevada Center for Surveys, Evaluations, and Statistics. Our econometric approach centers on a fully robust count data (Poisson) model, estimated via Quasi-Maximum Likelihood. ResultsWe find that for our sample PM2.5 effects are largely robust to the inclusion of both pollen counts and temporal indicators. In contrast, pollen effects vanish when time fixed effects are added, pointing at their correlation with unobserved temporal confounders. At the same time, model fit improves with the inclusion of temporal indicators. Based on our preferred specification, we find a significant PM2.5 effect of approximately 0.5% additional hospital visits per day due to a one μg/m3 increase in PM2.5. This translates into expected augmented treatment costs of $2700 per day for the same unit-change in PM2.5. These figures can mount quickly when more pronounced and/or longer episodes of particulate matter pollution are considered, perhaps due to wildfire smoke. For instance, the expected increase in patients and costs due to a month-long 10-unit-jump of PM2.5 over the long-run annual average would amount to an extra 70 patients and approximately $680,000 in additional treatment costs.

Prevalence of respiratory conditions among people who use illicit opioids: a systematic review.

There are growing concerns over the respiratory health of people who use illicit opioids due to high rates of opioid inhalation and tobacco smoking in this group. This study aimed to summarize the evidence relating illicit opioid use with poor respiratory health. A systematic review of the literature on the association between illicit opioid use and respiratory health was undertaken in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance (PROSPERO ID=CRD42017059953). Electronic searches of MEDLINE, Embase, PsycINFO, CINAHL and the Cochrane Library databases were undertaken (English language, published January 1980-November 2018). All study designs excluding case studies were considered. Studies were undertaken in community and hospital settings in the United States (n=23), United Kingdom (n=7), Australia (n=7), the Netherlands (n=2), Canada (n=2), Ireland (n=1), Spain (n=1) and Iran (n=1). Measurements of respiratory disease, including asthma and chronic obstructive pulmonary disease (COPD) and related symptoms were extracted. Data on respiratory-related deaths and hospital admissions were also extracted. Meta-analysis of prevalence data was undertaken using a random effects meta-analysis model with parameters estimated using Markov chain Monte Carlo simulation. Meta-analyses estimated prevalence of asthma in people who inject illicit opioids as 8.5% [95% predictive interval (PrI)=0.2%, 74.0%] and as 20.2% (95% PrI=4.2%, 59.2%) in people who inhale illicit opioids. Prevalence of COPD in people who inject illicit opioids was estimated as 2.7% (95% PrI=0.0%, 50.4%) and as 17.9% (95% PrI=0.6%, 89.5%) in people who inhale illicit opioids. There was evidence of moderate to extreme heterogeneity across studies. There is evidence of increased burden of respiratory diseases in people who use illicit opioids. Due to the heterogeneity of study design and samples, it is difficult to gain accurate estimates of the prevalence of respiratory disease in this population.

Risk of respiratory hospital admission associated with modelled concentrations of Aspergillus fumigatus from composting facilities in England

Bioaerosols have been associated with adverse respiratory-related health effects and are emitted in elevated concentrations from composting facilities. We used modelled Aspergillus fumigatus concentrations, a good indicator for bioaerosol emissions, to assess associations with respiratory-related hospital admissions. Mean daily Aspergillus fumigatus concentrations were estimated for each composting site for first full year of permit issue from 2005 onwards to 2014 for Census Output Areas (COAs) within 4 km of 76 composting facilities in England, as previously described (Williams et al., 2019). We fitted a hierarchical generalized mixed model to examine the risk of hospital admission with a primary diagnosis of (i) any respiratory condition, (ii) respiratory infections, (iii) asthma, (iv) COPD, (v) diseases due to organic dust, and (vi) Cystic Fibrosis, in relation to quartiles of Aspergillus fumigatus concentrations. Models included a random intercept for each COA to account for over-dispersion, nested within composting facility, on which a random intercept was fitted to account for clustering of the data, with adjustments for age, sex, ethnicity, deprivation, tobacco sales (smoking proxy) and traffic load (as a proxy for traffic-related air pollution). We included 249,748 respiratory-related and 3163 Cystic Fibrosis hospital admissions in 9606 COAs with a population-weighted centroid within 4 km of the 76 included composting facilities. After adjustment for confounders, no statistically significant effect was observed for any respiratory-related (Relative Risk (RR) = 0.99; 95% Confidence Interval (CI) 0.96–1.01) or for Cystic Fibrosis (RR = 1.01; 95% CI 0.56–1.83) hospital admissions for COAs in the highest quartile of exposure. Similar results were observed across all respiratory disease sub-groups. This study does not provide evidence for increased risks of respiratory-related hospitalisations for those living near composting facilities. However, given the limitations in the dispersion modelling, risks cannot be completely ruled out. Hospital admissions represent severe respiratory episodes, so further study would be needed to investigate whether bioaerosols emitted from composting facilities have impacts on less severe episodes or respiratory symptoms.

Longevity of pulmonary rehabilitation benefit for chronic obstructive pulmonary disease—health care utilisation in the subsequent 2 years

BackgroundThe primary aim was to determine the healthcare utilisation benefits including respiratory-related hospital admissions, hospital admission days and emergency department presentations in the 0–12 and 12–24 months postpulmonary rehabilitation compared...

Age-specific seasonal associations between acute exposure to PM2.5 sources and cardiorespiratory hospital admissions in California

Numerous studies have explored the relationships between short-term exposure to fine particulate matter (PM2.5) and morbidity. However, few studies have investigated which PM2.5 sources and constituents contribute to the health associations, and even fewer studies are available which explored age or seasonal effect modification for the associations between PM2.5 sources and health. We explored age-specific associations between short-term exposure to PM2.5 chemical constituents and its sources, and hospital admissions in California. We linked hospital admission data (n = 1,679,094) with PM2.5 chemical constituents and source apportionment data for eight sites in California for the period of 2002–2009. Site-specific source apportionment was conducted using Positive Matrix Factorization, and five PM2.5 sources were commonly identified in most sites (biomass burning, soil, secondary ammonium nitrate, secondary ammonium sulfate, and vehicular emissions). Age-stratified Poisson time-series regression was conducted for each site, and the health risk estimates were combined to generate overall age-specific associations with cardiovascular- and respiratory-related hospital admissions. We further conducted seasonal interaction models to assess seasonal effect modification. An interquartile range increase in PM2.5 vehicular emissions was associated with increased risk of cardiovascular-related hospital admission at lag 0 (1.32% [95% confidence interval (CI): 0.16, 2.49]) for elderly people (≥65 years old). Exposure to PM2.5 vehicular emissions increased the risk of respiratory-related hospitalizations at lag 2 (3.58% [95% CI: 0.90, 6.33]) for children (0–18 years old). Risk estimates of PM2.5 total mass, vehicular emissions, and its related constituents (e.g., iron) for respiratory admissions were higher in the warm season among children. Heterogeneous seasonal estimates were not observed for other age groups. Our results suggest that short-term exposures to several PM2.5 sources and their related constituents are more harmful than exposures to other pollutants, particularly for children in summer. Identifying toxic sources is important for developing effective interventions and protecting susceptible populations.

Economic burden of care and treatment options for patients with Rett syndrome: Two systematic literature reviews

Rett syndrome, a rare disorder caused by mutations in the X-linked MECP2 gene, occurs almost exclusively in girls and leads to severe developmental impairment. Two systematic literature reviews (economic burden; clinical trials) were performed on 25 June 2018. Databases included DARE (economic burden); ClinicalTrials.gov (clinical trials); MEDLINE®, Embase, and Cochrane Library (both). Intervention type and costs were extracted from 9/133 identified articles (4 studies). Efficacy and safety were extracted from 28/652 retrieved articles (20 studies). In the economic burden studies, enteral feeding and assisted walking increased the risk of respiratory-related hospital admissions, while length-of-stay was lower in younger patients. Mean recovery-stay after scoliosis-correcting surgery was 18.2 and 12.3 days in each of two studies. Care integration improved outcomes and reduced costs. Of 20 clinical studies identified (15 randomized controlled trials, 5 single-arm; N = 8–82; follow-up 1–26 months): 19 focused on pharmacological symptom treatment; 1 examined the effects of environmental enrichment; none targeted the underlying cause. The most common primary endpoints: Rett Syndrome Gross Motor Scale; Clinical Severity Score, Motor and Behavioral Assessment; Anxiety Depression and Mood Scale. Significant clinical benefits were demonstrated for naltrexone, trofinetide, and mecasermin vs placebo; most treatments showed no significant improvement. Recent clinical guidelines/treatment patterns data were limited. Little data exist on costs of Rett syndrome management, and effective therapies are lacking; those available only manage symptoms. There is demand for safe and effective treatments targeting the underlying cause (eg, gene therapy), which could improve quality of life and prognosis of patients with Rett syndrome.

Effects of salivary gland botulinum Toxin-A on drooling and respiratory morbidity in children with neurological dysfunction

ObjectiveTo describe the effects of salivary gland Botulinum Toxin-A (SG BoNT-A) on children with drooling due to neurological dysfunction. MethodsThis was a 3½-year prospective observational case series design of children referred for SG BoNT-A injections at a pediatric hospital (2010–2014). Outcomes were parent-reported severity, frequency, impact of drooling, and respiratory morbidity; and, from hospital records, number of respiratory hospital admissions. ResultsOut of 17 children treated, complete data were available for 15 (including 8 boys) aged 3–14 years (Mean = 9.9 years; SD = 3.4), with a combined total of 71 injections. Most had cerebral palsy (n = 11), classified as Level V (n = 10) or IV (n = 1) on the Gross Motor Function Classification Scale (GMFCS). In almost all instances, parents reported reductions in severity, frequency, and impact of drooling, and parent-reported respiratory morbidity. Among those with posterior drooling (n = 12), most children (n = 10) did not have advanced respiratory disease. A trend towards reduced respiratory-related hospital admissions was observed during SG BoNT-A treatment periods. ConclusionSG BoNT-A can improve severity, frequency, and impact of drooling. It can also reduce respiratory-related hospital admissions in children with posterior drooling without advanced respiratory disease. For children with advanced respiratory disease, it may reduce severity and impact of drooling.

Self-management interventions including action plans for exacerbations versus usual care in patients with chronic obstructive pulmonary disease.

Self-management interventions including action plans for exacerbations versus usual care in patients with chronic obstructive pulmonary disease.

Comparative effectiveness of high-dose versus standard-dose influenza vaccination on numbers of US nursing home residents admitted to hospital: a cluster-randomised trial

Immune responses to influenza vaccines decline with age, reducing clinical effectiveness. We compared the effect of the more immunogenic high-dose trivalent influenza vaccine with a standard-dose vaccine to identify the effect on reducing hospital admissions of nursing home residents in the USA. We did a single-blind, pragmatic, comparative effectiveness, cluster-randomised trial with a 2 × 2 factorial design. Medicare-certified nursing homes in the USA located within 50 miles of a Centers for Disease Control and Prevention influenza reporting city were recruited, so long as the facilities were not located in a hospital, had more than 50 long-stay residents, had less than 20% of the population aged under 65 years, and were not already planning to administer the high-dose influenza vaccine to residents. Enrolled nursing homes were randomised to a facility-wide standard of care for the residents of either high dose or standard dose as the vaccine for the 2013-14 influenza season and half of each group were randomly allocated to free vaccines for staff. Individual residents were included in the analysis group if they were aged 65 years or older and were long-stay residents (ie, had been in the facility 90 days or more before commencing the influenza vaccination programme). The analysts and investigators with access to the raw data were masked to study group by coding the groups until after the analyses were complete. The primary outcome was hospital admissions related to pulmonary and influenza-like illness between Nov 1, 2013, and May 31, 2014, identified from Medicare hospital claims available for residents who were without private health insurance (ie, those who were considered Medicare fee-for-service). We obtained data from the Centers for Medicare & Medicaid Services (CMS) and enrolled facilities. The analyses used marginal Poisson and Cox proportional hazards regression, accounting for clustering of residents within homes, on an intention-to-treat basis, adjusting for facility clustering and prespecified covariates. Safety data were voluntarily reported according to the standard of care. This trial is registered with ClinicalTrials.gov, number NCT01815268. 823 facilities were recruited to the study between March and August, 2013, to participate in the trial, of which 409 facilities were randomised for residents to receive high-dose vaccine, and 414 facilities for residents to receive standard-dose vaccine. The facilities housed 92 269, of whom 75 917 were aged 65 years or older and 53 008 were also long-stay residents, and 38 256 were matched to Medicare hospital claims as of Nov 1, 2013. Staff vaccination rates did not differ between groups, so analyses focused on the high-dose versus standard-dose vaccine comparison. On the basis of Medicare fee-for-service claims, the incidence of respiratory-related hospital admissions was significantly lower in facilities where residents received high-dose influenza vaccines than in those that received standard-dose influenza vaccines (0·185 per 1000 resident-days or 3·4% over 6 months vs 0·211 per 1000 resident-days or 3·9% over 6 months; unadjusted relative risk of 0·888, 95% CI 0·785-1·005, 0=0·061, and adjusted relative risk 0·873, 0·776-0·982, p=0·023). When compared with standard-dose vaccine, high-dose influenza vaccine can reduce risk of respiratory-related hospital admissions from nursing home residents aged 65 years and older. Sanofi Pasteur, Swiftwater, PA, USA.