Rotavirus Vaccination Likely to Be Cost Saving to Society in the United States.

BACKGROUND: Following the introduction of rotavirus immunization in 2006 in the United States, there were substantial declines in the domestic rotavirus disease burden. In this study, we assess the value for money achieved by the program in the decade following vaccine introduction. METHODS: We applied an age-specific, static, multicohort compartmental model to examine the impact and cost-effectiveness of the US rotavirus immunization program in children <5 years of age using healthcare utilization data from 2001 to 2015 inclusive. We calculated the incremental cost-effectiveness ratio (ICER) per quality-adjusted life year (QALY) gained from both a healthcare system and societal perspective. RESULTS: Declines in healthcare use associated with the rotavirus and acute gastroenteritis occurred from 2006 and continued to grow before stabilizing from 2010 through 2011. From 2011 to 2015, an estimated annual average of approximately 118 000 hospitalizations, 86 000 emergency department presentations, and 460 000 outpatient and physician office visits were prevented. From a societal perspective during this same period, the program was estimated to be cost saving in the base case model and in >90% of probabilistic sensitivity analysis simulations and from a healthcare system perspective >98% of simulations found an ICER below $100 000 per QALY gained. CONCLUSIONS: After the program stabilized, we found the rotavirus immunization in the United States was likely to have been cost saving to society. The greater than expected healthcare and productivity savings reflect the success of the rotavirus immunization program in the United States.

Rapid mapping of the spatial and temporal intensity of influenza.

Surveillance of influenza epidemics is a priority for risk assessment and pandemic preparedness, yet representation of their spatiotemporal intensity remains limited. Using the epidemic of influenza type A in 2016 in Australia, we demonstrated a simple but statistically sound adaptive method of mapping epidemic evolution over space and time. Weekly counts of persons with laboratory confirmed influenza type A infections in Australia in 2016 were analysed by official national statistical region. Weekly standardised epidemic intensity was represented by a standard score (z-score) calculated using the standard deviation of below-median counts in the previous 52 weeks. A geographic information system (GIS) was used to present the epidemic progression. There were 79,628 notifications of influenza A infections included. Of these, 79,218 (99.5%) were allocated to a geographical area. The GIS maps indicated areas of elevated epidemic intensity across Australia by week and area that were consistent with the observed start, peak and decline of the epidemic when compared with counts aggregated at the state and territory level. This simple, adaptable approach could improve local level epidemic intelligence in a variety of settings and for other diseases. It may also facilitate increased understanding of geographic epidemic dynamics.

Comparison of statistical methods for the early detection of disease outbreaks in small population settings.

Objectives: This study examines the performance of 6 aberration detection algorithms for the early detection of disease outbreaks in small population settings using syndrome-based early warning surveillance data collected by the Pacific Syndromic Surveillance System (PSSS). Although previous studies have proposed statistical methods for detecting aberrations in larger datasets, there is limited knowledge about how these perform in the presence of small numbers of background cases. Methods: To address this gap a simulation model was developed to test and compare the performance of the 6 algorithms in detecting outbreaks of different magnitudes, durations, and case distributions. Results: The study found that while the Early Aberration Reporting System-C1 algorithm developed by Hutwagner et al. outperformed others, no single approach provided reliable monitoring across all outbreak types. Furthermore, aberration detection approaches could only detect very large and acute outbreaks with any reliability. Conclusion: The findings of this study suggest that algorithm-based approaches to outbreak signal detection perform poorly when applied to settings with small numbers of background cases and should not be relied upon in these contexts. This highlights the need for alternative approaches for accurate and timely outbreak detection in small population settings, particularly those that are resource-constrained.

Budget Impact Analysis of Utilization of Sacubitril/Valsartan for the Treatment of Heart Failure With Reduced Ejection Fraction in the Philippines.

OBJECTIVES: This study aimed to estimate the financial and economic impact of sacubitril/valsartan compared with enalapril for the treatment and prevention of hospitalization/rehospitalization because of heart failure with reduced ejection fraction (HFrEF). METHODS: The budget impact analysis was guided by the Philippine Reference Case and ISPOR's Principles of Good Practice for Budget Impact Analysis. A government-funded healthcare payer perspective and a societal perspective were considered. Data collection was guided by the pathways of disease progression and care. Collection of costing data followed a bottom-up approach. The model was based on a Markov model used in a study in Thailand. RESULTS: Over the next 5 years, there will be 17 625 less hospitalizations (∼5.1% less than enalapril arm) and 7968 less cardiovascular-related deaths (∼7.0% less than enalapril arm). In 5 years, the total cost of treating patients with HFrEF with sacubitril/valsartan at current market coverage and annual growth conditions is ₱15.430 billion, which is ₱11.077 billion higher than fully treating with enalapril only. The total required additional investment with treatment of sacubitril/valsartan compared with the full enalapril arm are ₱407 million (at 30-day coverage), ₱800 million (at 60-day coverage), and ₱1.181 billion (at 90-day coverage). If hospitalizations costs alone are considered, only the 30-day coverage is cost-saving. If a societal perspective is considered, all options are cost-saving where at least ₱4.003 billion is saved by the economy. CONCLUSION: The initial investment required to treat patients with HFrEF with sacubitril/valsartan is high; nevertheless, the year-on-year cost deficit shrinks in favor of investing in sacubitril/valsartan treatment.

Returning to the emergency department: a retrospective analysis of mental health re-presentations among young people in New South Wales, Australia.

OBJECTIVES: This study aimed to describe mental health emergency department (ED) presentations among young people aged 8-26 years in New South Wales, Australia, and to identify key characteristics associated with higher risk of ED mental health re-presentation. DESIGN, SETTING AND PARTICIPANTS: Retrospective analysis of linked ED data records for mental health presentations between 1 January 2015 and 30 June 2018. MAIN OUTCOME MEASURES: The main outcome was the total number of mental health ED re-presentations within 1 year, following initial presentation. Count regression models were fitted to estimate factors associated with higher likelihood of re-presentations. RESULTS: Forty thousand two hundred and ninety patients were included in the analyses, and 9713 (~25%) re-presented during the following year; 1831 (20%) presented at least three times. On average, patients re-presented 0.61 times per 365 person-days, with average time until first re-presentation of ~92 days but greatest risk of re-presentation within first 30-60 days. Young people with self-harm or suicidal diagnoses at initial presentation were more likely to re-present. Re-presentations were highest among young people <15 years (IRR 1.18 vs ≥20 years old), female (IRR=1.13 vs male), young people residing outside of major cities (IRR 1.08 vs major cities) and Aboriginal and Torres Strait Islander young people (IRR 1.27 vs non-Indigenous). CONCLUSIONS: ED mental health re-presentation is high among young people. We demonstrate factors associated with re-presentation that EDs could target for timely, high-quality care that is youth friendly and culturally safe, with appropriate referral pathways into community-based primary and mental healthcare services.

Sex differences in sepsis hospitalisations and outcomes in older women and men: A prospective cohort study.

PURPOSE: To examine the association of sex with hospitalisation due to sepsis and related outcomes. METHODS: Prospective cohort study of 264,678 adults, average age 62.7 years at recruitment (2006-2009) in Australia. Participants were followed for sepsis hospitalisation identified using the International Classification of Diseases coding. Outcomes included sex differences in the risk of an incident sepsis hospitalisation, mortality, length of ICU and hospital stay and readmissions during the following year. RESULTS: Over 2,070,343 years of follow-up there were 12,912 sepsis hospitalisations, 59.6% in men. Age-standardised risk of hospitalisation was higher in men versus women (10.37 vs 6.77 per 1,000 person years; age-adjusted HR 1.58; 95% CI 1.53-1.59) and did not attenuate after adjusting for sociodemographics, health behaviours and co-morbidities. Relative risks were similar for sepsis-related ICU admissions (adjusted HR 1.72; 95% CI 1.57-1.88). Death at one year was more common in men than women (39.3% vs 33.7% p<0.001). After adjusting for age, men had a longer hospital (12.0 vs 11.2 days; p<0.001) and ICU (6.5 vs 5.8 days; p<0.001) stays and were more likely to be readmitted to hospital for sepsis (22.3 vs 19.4%; p<0.001) or any reason (73.0% vs 70.7%; p<0.001) at one year. CONCLUSION: In older adults, compared to women, men are at an increased risk of sepsis hospitalisation, sepsis-related ICU admission, death and readmission to hospital within one year after a sepsis hospitalisation. Understanding these sex differences and their mechanisms may offer opportunities for better prevention and management and improved patient outcomes.

Estimating pertussis incidence in general practice using a large Australian primary care database.

BACKGROUND: While pertussis is notifiable in most countries, notifications typically underestimate the true pertussis burden. We explored the incidence of pertussis in general practice in Australia. METHODS: Using MedicineInsight, a large longitudinal electronic medical record database of general practice (primary care) encounters which includes >1.5 million patients, we first defined a cohort of active patients and then used free-text search algorithms to identify patients with pertussis-related encounters. We defined and identified pertussis-related encounters in four patient categories: pertussis-associated (category 1), potential pertussis (category 2), epidemiologically-linked pertussis (category 3), and symptoms consistent with pertussis (category 4). Incident pertussis-related encounter rates per 100,000 active patients were calculated from Jan 2008 to Aug 2015. RESULTS: Estimated mean annual pertussis incidence increased as definitions were expanded, from 94.3 (category 1 patients only) to 148.8 (categories 1+2+3 patients combined) per 100,000 active patients per year. Monthly time-series corresponding to the first three categories were highly correlated (Pearson's r > 90% for each pair), but each was poorly correlated with category 4. For categories 1+2+3, the highest incidence was among 0-4 and 5-9 year olds. Incidence was 30% higher in females than males (i.e. 184.5 vs 139.8 per 100,00 active patients for categories 1-3 patients combined). Pertussis-associated incidence (category 1) was similar to national pertussis notification rates. Categories 2 and 3 added 25% and 33%, respectively, on average relative to category 1 incidence. The estimated incidence from categories 1+2+3 together were on average 64% higher than national pertussis notification rates. CONCLUSION: We provide comprehensive estimates of pertussis-related incidence in general practice (primary care), well in excess of notified pertussis incidence in Australia. This highlights the utility of MedicineInsight data in providing a greater understanding of the burden of medically-attended pertussis infections.

Vaccine coverage in children born to migrant mothers in Australia: A population-based cohort study.

BACKGROUND: Overall, infant immunisation coverage is currently >90% in Australia, but there are pockets of under-immunised children including children from migrant backgrounds. This study aimed to examine whether on-time vaccination coverage of diphtheria-tetanus-pertussis dose 3 (DTP3) for children born in Australia differed by mother's region of birth and if so, what factors were associated with these differences. METHODS: We conducted a population-based cohort study using linked data on perinatal, immunisation and birth records for 2 million children born in Western Australia and New South Wales between 1996 and 2012. We assessed on-time coverage of DTP3 (vaccination from 2 weeks prior to, and up until 30 days after, the due date) in children with mothers born overseas. Logistic regression models were developed to determine factors associated with on-time coverage for each maternal region of birth and all regions combined, adjusting for a range of demographic factors. Adjusted estimates of coverage were calculated for the different regions of birth. RESULTS: On-time DTP3 coverage was 76.2% in children of Australian born mothers, lower in children of mothers from Oceania (66.7%) and North America (68%), and higher in children born to mothers from South-East Asia (79.9%) and Southern Asia (79.3%). While most variables were consistently associated with lower coverage in all regions of birth, higher socioeconomic status and jurisdiction of birth showed varied results. Adjusted estimates of DTP3 coverage increased in children born to mothers from Australia (78.3%), Oceania (70.5%), Northern Africa (81.5%) and the Middle East (79.6%). DTP3 coverage decreased in children born to mothers from Europe and former USSR (74.6%), North-east Asia (75.2%), Southern Asia (76.7%), North America (65.5) and South/Central America and the Caribbean (73.2%). CONCLUSIONS: On-time vaccination rates differed by mother's region of birth. More research is needed to determine the main reasons for these remaining differences to improve vaccine uptake and also help guide policy and practice.

Incidence and outcomes of sepsis in Aboriginal and Torres Strait Islander and non-Indigenous residents of New South Wales: population-based cohort study.

Objective: To estimate the incidence and outcomes of sepsis hospitalisations in Aboriginal and Torres Strait Islander and non-Indigenous residents of New South Wales. Design and participants: Prospective cohort study of residents aged 45 years and older, recruited between 2006 and 2009, and followed for hospitalisation for sepsis. Main outcome measures: Incidence and hazard ratio (HR) of sepsis hospitalisation and intensive care unit (ICU) admission identified using International Classification of Diseases (10th revision) coding on discharge data. Length of stay, readmission and mortality in those admitted for sepsis. Results: Of 264 678 participants, 1928 (0.7%) identified as Aboriginal and/or Torres Strait Islander. Sepsis hospitalisation was higher in Aboriginal and Torres Strait Islander participants (8.67 v 6.12 per 1000 person-years; age- and sex-adjusted HR, 2.35; 95% CI, 1.98-2.80) but was attenuated after adjusting for sociodemographic factors, health behaviour and comorbidities (adjusted HR, 1.56; 95% CI, 1.31-1.86). Among those hospitalised for sepsis, after adjusting for age and sex, there were no differences between the proportions of Aboriginal and Torres Strait Islander and non-Indigenous participants admitted to an ICU (18.0% v 16.1%; P = 0.42) or deceased at 1 year (36.1% v 36.8%; P = 0.92). Aboriginal and Torres Strait Islander participants had shorter lengths of hospital stay (9.98 v 11.72 days; P < 0.001) and ICU stay (4.38 v 6.35 days; P < 0.001) than non-Indigenous participants. Overall, more than 70% of participants were readmitted to hospital within 1 year. Conclusion: We found that the rate of sepsis hospitalisation in NSW was higher for Aboriginal and Torres Strait Islander adults. Culturally appropriate, community-led strategies targeting chronic disease prevention and the social determinants of health may reduce this gap. Preventing readmission following sepsis is a priority for all Australians.

Understanding COVID-19 dynamics and the effects of interventions in the Philippines: A mathematical modelling study.

BACKGROUND: COVID-19 initially caused less severe outbreaks in many low- and middle-income countries (LMIC) compared with many high-income countries, possibly because of differing demographics, socioeconomics, surveillance, and policy responses. Here, we investigate the role of multiple factors on COVID-19 dynamics in the Philippines, a LMIC that has had a relatively severe COVID-19 outbreak. METHODS: We applied an age-structured compartmental model that incorporated time-varying mobility, testing, and personal protective behaviors (through a "Minimum Health Standards" policy, MHS) to represent the first wave of the Philippines COVID-19 epidemic nationally and for three highly affected regions (Calabarzon, Central Visayas, and the National Capital Region). We estimated effects of control measures, key epidemiological parameters, and interventions. FINDINGS: Population age structure, contact rates, mobility, testing, and MHS were sufficient to explain the Philippines epidemic based on the good fit between modelled and reported cases, hospitalisations, and deaths. The model indicated that MHS reduced the probability of transmission per contact by 13-27%. The February 2021 case detection rate was estimated at ~8%, population recovered at ~9%, and scenario projections indicated high sensitivity to MHS adherence. INTERPRETATION: COVID-19 dynamics in the Philippines are driven by age, contact structure, mobility, and MHS adherence. Continued compliance with low-cost MHS should help the Philippines control the epidemic until vaccines are widely distributed, but disease resurgence may be occurring due to a combination of low population immunity and detection rates and new variants of concern.

High healthcare resource utilisation due to pertussis in Australian adults aged 65 years and over.

BACKGROUND: In the context of co-morbid illness and increasing age, data on excess morbidity from pertussis in older adults is crucial for immunisation policy but has been largely limited to case-series. METHODS: We designed a matched case-control study nested within a population-based cohort of 267,153 adults aged ≥45 years in New South Wales, Australia (The 45 and Up Study cohort). Excess hospital bed days, emergency department (ED) admissions, general practitioner (GP) visits, and prescriptions were estimated using negative binomial regression models. An additional self-controlled analysis was also conducted to validate the main models, and to evaluate results for those with either asthma or a body mass index (BMI)≥30 compared to those without these risk factors. RESULTS: Based on 524 pairs of PCR-confirmed pertussis cases and matched controls, we estimated an excess healthcare utilisation per case of 2.5 prescriptions (95% CI: 0.2-4.7), of which 1.1 (95% CI: 0.5-2.2) were antibiotics, 2.3 GP visits (95% CI: 2.0-2.6), and 0.1 ED admissions (95% CI: 0.1-0.2). Compared to those 45-64 years, cases ≥65 years had a significantly greater excess for all prescriptions (1.1 vs 4.7/case), antibiotic prescriptions (0.1 vs 2.2/case), and ED admissions (0.1 vs 0.2/case), but no significant excess of respiratory-related hospital bed days. An additional self-controlled analysis confirmed that cases with either asthma or BMI≥30 had higher overall healthcare utilisation but this was not associated with pertussis infection. CONCLUSION: We found a substantial excess outpatient healthcare burden among adults aged 65 years and over with PCR-confirmed pertussis, supporting further evaluation of preventive measures.