Jeffrey Cannon

Childhood Behavior Problems and Age at First Sexual Intercourse: A Prospective Birth Cohort Study

BACKGROUND AND OBJECTIVES: Early first sexual intercourse (FSI) is a risk factor for unplanned teenage pregnancy, sexually transmitted infection, and adverse social, emotional, and physical health outcomes in adolescence and into adulthood. The aim of this study was to examine relationships between internalizing (eg, anxious/depressed, withdrawn) and externalizing (eg, delinquent, aggressive) behavior problems in childhood and age at FSI. METHODS: We used a large, population-based birth cohort (The Western Australian Pregnancy Cohort [Raine] Study) to address this question. Child behavior was measured by using the Child Behavior Checklist collected from parents at ages 2, 5, 8, 10, and 14 and scores calculated for total, internalizing, and externalizing behavior problems. At age 17, 1200 participants reported sexual behavior. RESULTS: Participants with clinically significant Child Behavior Checklist scores (T ≥60) were at increased risk for earlier first sexual intercourse (FSI) (<16 years). Adjusted odds ratios revealed that total and externalizing behavior problems from age 5 years onward significantly increased the risk of earlier FSI for boys. In girls, externalizing problems from age 10 years increased the risk for earlier FSI. Internalizing problems at ages 8 and 10 were significantly associated with early FSI for boys but not girls. CONCLUSIONS: Externalizing behavior from as early as 5 in boys and 10 in girls is a significant risk factor for earlier age at FSI. Adolescent sexual health promotion should consider early intervention in children with behavior problems, particularly boys.

Age at menarche and age at first sexual intercourse: A prospective cohort study

OBJECTIVE: Younger age at menarche (AAM) may put girls at risk for earlier first sexual intercourse (FSI). Young age at FSI has far-reaching negative outcomes. We describe the longitudinal relationship between AAM and FSI in a large prospective birth cohort. METHODS: AAM was collected from 554 girls from the Western Australia (Raine) Pregnancy Cohort Study, prospectively from age 10 or retrospectively at age 14. Age at FSI was collected at ages 17 and 20. Cox regression models describe likelihood of FSI by age and years since menarche for younger (<12 years) and older (≥14 years) AAM relative to average AAM (12–13 years). RESULTS: Girls with younger AAM and average AAM were equally likely to have FSI by age 16 (adjusted hazard ratio [aHR]: 0.90 [95% confidence interval (CI): 0.60–1.35]). FSI by age 16 was less likely among girls with older AAM than those with average AAM (aHR: 0.35 [95% CI: 0.17–0.72]). Girls with younger AAM had a longer median interval between menarche and FSI than girls with average AAM (5.0 years [interquartile range: 4.4–8.5 years] vs 3.7 years [interquartile range: 2.4–5.3 years]). Those with younger AAM were less likely to report FSI within 4 years of menarche than those with average AAM (0–2 years aHR: 0.04 [95% CI: 0.01–0.31]; 2–4 years aHR: 0.36 [95% CI: 0.23–0.55]). By age 20, 429 girls (77.4%) reported FSI. CONCLUSIONS: Younger AAM was not a risk factor for younger age at FSI in this cohort.

Echocardiographic screening for rheumatic heart disease in indigenous Australian children: A cost-utility analysis

Background Rheumatic heart disease (RHD) remains a leading cause of cardiovascular morbidity and mortality in children and young adults in disadvantaged populations. The emergence of echocardiographic screening provides the opportunity for early disease detection and intervention. Using our own multistate model of RHD progression derived from Australian RHD register data, we performed a cost–utility analysis of echocardiographic screening in indigenous Australian children, with the dual aims of informing policy decisions in Australia and providing a model that could be adapted in other countries. Methods and Results We simulated the outcomes of 2 screening strategies, assuming that RHD could be detected 1, 2, or 3 years earlier by screening. Outcomes included reductions in heart failure, surgery, mortality, disability‐adjusted life‐years, and corresponding costs. Only a strategy of screening all indigenous 5‐ to 12‐year‐olds in half of their communities in alternate years was found to be cost‐effective (incremental cost‐effectiveness ratio less than AU

Rheumatic heart disease severity, progression and outcomes: A multi-state model

50 000 per disability‐adjusted life‐year averted), assuming that RHD can be detected at least 2 years earlier by screening; however, this result was sensitive to a number of assumptions. Additional modeling of improved adherence to secondary prophylaxis alone resulted in dramatic reductions in heart failure, surgery, and death; these outcomes improved even further when combined with screening. Conclusions Echocardiographic screening for RHD is cost‐effective in our context, assuming that RHD can be detected ≥2 years earlier by screening. Our model can be adapted to any other setting but will require local data or acceptable assumptions for model parameters.

Economic implications of poor access to antenatal care in rural and remote Western Australian Aboriginal communities: An individual sampling model of pregnancy

Background Rheumatic heart disease (RHD) remains a disease of international importance, yet little has been published about disease progression in a contemporary patient cohort. Multi‐state models provide a well‐established method of estimating rates of transition between disease states, and can be used to evaluate the cost‐effectiveness of potential interventions. We aimed to create a multi‐state model for RHD progression using serial clinical data from a cohort of Australian patients. Methods and Results The Northern Territory RHD register was used to identify all Indigenous residents diagnosed with RHD between the ages of 5 and 24 years in the time period 1999–2012. Disease severity over time, surgeries, and deaths were evaluated for 591 patients. Of 96 (16.2%) patients with severe RHD at diagnosis, 50% had proceeded to valve surgery by 2 years, and 10% were dead within 6 years. Of those diagnosed with moderate RHD, there was a similar chance of disease regression or progression over time. Patients with mild RHD at diagnosis were the most stable, with 64% remaining mild after 10 years; however, 11.4% progressed to severe RHD and half of these required surgery. Conclusions The prognosis of young Indigenous Australians diagnosed with severe RHD is bleak; interventions must focus on earlier detection and treatment if the observed natural history is to be improved. This multi‐state model can be used to predict the effect of different interventions on disease progression and the associated costs.

Cost effectiveness of universal umbilical cord blood gas and lactate analysis in a tertiary level maternity unit

Australian Aboriginal women attend antenatal care less frequently and experience poorer pregnancy outcomes than non-Aboriginal women. Improving access to antenatal care is recognised as a means to improve pregnancy outcomes for mother and baby.

An economic case for a vaccine to prevent group A streptococcus skin infections

Abstract Objective: There is an increasing body of literature supporting universal umbilical cord blood gas analysis (UCBGA) into all maternity units. A significant impediment to UCBGA’s introduction is the perceived expense of the introduction and associated ongoing costs. Consequently, this study set out to conduct the first cost-effectiveness analysis of introducing universal UCBGA. Methods: Analysis was based on 42,100 consecutive deliveries ≥23 weeks of gestation at a single tertiary obstetric unit. Within 4 years of UCBGA’s introduction there was a 45% reduction in term special care nursery (SCN) admissions >2499 g. Incurred costs included initial and ongoing costs associated with universal UCBGA. Averted costs were based on local diagnosis-related grouping costs for reduction in term SCN admissions. Incremental cost-effectiveness ratio (ICER) and sensitivity analysis results were reported. Results: Under the base-case scenario, the adoption of universal UCBGA was less costly and more effective than selective UCBGA over 4 years and resulted in saving of AU

Seasonal and regional patterns of lower leg cellulitis in Western Australia: Seasonal and regional patterns of lower leg cellulitis

641,532 while adverting 376 SCN admissions. Sensitivity analysis showed that UCBGA was cost-effective in 51.8%, 83.3%, 99.6% and 100% of simulations in years 1, 2, 3 and 4. These conclusions were not sensitive to wide, clinically possible variations in parameter values for neonatal intensive care unit and SCN admissions, magnitude of averted SCN admissions, cumulative delivery numbers, and SCN admission costs. Conclusions: Universal UCBGA is associated with significant initial and ongoing costs; however, potential averted costs (due to reduced SCN admissions) exceed incurred costs in most scenarios.

Prospective cohort study of childhood behaviour problems and adolescent sexual risk-taking: gender matters

BACKGROUND Group A streptococcus (GAS) causes an exceptionally diverse range of diseases, raising questions about the optimal product characteristics of a commercially viable vaccine. The objectives of this study were to (1) estimate the current health and economic burdens caused by 24 diseases attributable to GAS each year in Australia and (2) use these estimates to explore the value of a GAS vaccine for different clinical indications, age schedules, and population groups. METHODS For objective 1, we estimated the population heath and economic burdens by synthesising data from administrative databases, nationally representative surveys, literature reviews, public reimbursement schedules, and expert opinion. For objective 2, we modelled the prospective lifetime burden of GAS for all infants from birth, for children from 5 years of age, and for adults from 65 years of age. A vaccine was assumed to reduce each GAS disease by 70% for a period of 10 years, and the difference in outcomes between vaccinated and non-vaccinated cohorts were used to calculate the cost-effective value of vaccination. RESULTS The annual health and economic burdens of GAS diseases totalled 23,528 disability-adjusted life years and AU

Severe lower limb cellulitis: defining the epidemiology and risk factors for primary episodes in a population-based case-control study

185.1 million in healthcare costs respectively; approximately half of each measure was due to cellulitis, followed by other skin infections and throat infections. Reducing the incidence of throat infections, skin infections, and cellulitis in non-Indigenous cohorts resulted in 30%, 33%, and 28% of the total vaccine value for an infant schedule (cost-effective vaccine price AU