Improving access to mental health care: a system dynamics model of direct access to specialist care and accelerated specialist service capacity growth.

OBJECTIVE: To simulate the impact on population mental health indicators of allowing people to book some Medicare-subsidised sessions with psychologists and other mental health care professionals without a referral (direct access), and of increasing the annual growth rate in specialist mental health care capacity (consultations). DESIGN: System dynamics model, calibrated using historical time series data from the Australian Bureau of Statistics, HealthStats NSW, the Australian Institute of Health and Welfare, and the Australian Early Development Census. Parameter values that could not be derived from these sources were estimated by constrained optimisation. SETTING: New South Wales, 1 September 2021 - 1 September 2028. MAIN OUTCOME MEASURES: Projected mental health-related emergency department presentations, hospitalisations following self-harm, and deaths by suicide, both overall and for people aged 15-24 years. RESULTS: Direct access (for 10-50% of people requiring specialist mental health care) would lead to increases in the numbers of mental health-related emergency department presentations (0.33-1.68% of baseline), hospitalisations with self-harm (0.16-0.77%), and deaths by suicide (0.19-0.90%), as waiting times for consultations would increase, leading to disengagement and consequently to increases in adverse outcomes. Increasing the annual rate of growth of mental health service capacity (two- to fivefold) would reduce the frequency of all three outcomes; combining direct access to a proportion of services with increased growth in capacity achieved substantially greater gains than an increase in service capacity alone. A fivefold increase in the annual service growth rate would increase capacity by 71.6% by the end of 2028, compared with current projections; combined with direct access to 50% of mental health consultations, 26 616 emergency department presentations (3.6%), 1199 hospitalisations following self-harm (1.9%), and 158 deaths by suicide (2.1%) could be averted. CONCLUSION: The optimal combination of increased service capacity growth (fivefold) and direct access (50% of consultations) would have double the impact over seven years of accelerated capacity growth alone. Our model highlights the risks of implementing individual reforms without knowledge of their overall system effect.

A dynamic modelling analysis of the impact of tobacco control programs on population-level nicotine dependence.

According to the 'hardening hypothesis', average nicotine dependence will increase as less dependent smokers quit relatively easily in response to effective public health interventions, so that sustained progress in reducing smoking prevalence will depend on shifting the emphasis of tobacco control programs towards intensive treatment of heavily dependent smokers (who comprise an increasing fraction of continuing smokers). We used a system dynamics model of smoking behaviour to explore the potential for hardening in a population of smokers exposed to effective tobacco control measures over an extended period. Policy-induced increases in the per capita cessation rate are shown to lead inevitably to a decline in the proportion of smokers who are heavily dependent, contrary to the hardening hypothesis. Changes in smoking behaviour in Australia over the period 2001‒2016 resulted in substantial decreases in current smoking prevalence (from 23.1% in 2001 to 14.6% in 2016) and the proportion of heavily dependent smokers in the smoking population (from 52.1% to 36.9%). Public health interventions that have proved particularly effective in reducing smoking prevalence (tobacco tax increases, smoke-free environment legislation, antismoking mass media campaigns) are expected to also contribute to a decline in population-level nicotine dependence.

Policy options for endgame planning in tobacco control: a simulation modelling study.

OBJECTIVE: To investigate the potential impacts of several tobacco control interventions on adult daily smoking prevalence in the Australian state of Queensland, using a system dynamics model codeveloped with local and national stakeholders. METHODS: Eight intervention scenarios were simulated and compared with a reference scenario (business as usual), in which all tobacco control measures currently in place are maintained unchanged until the end of the simulation period (31 December 2037). FINDINGS: Under the business as usual scenario, adult daily smoking prevalence is projected to decline from 11.8% in 2017 to 5.58% in 2037. A sustained 50% increase in antismoking advertising exposure from 2018 reduces projected prevalence in 2037 by 0.80 percentage points. Similar reductions are projected with the introduction of tobacco wholesaler and retailer licensing schemes that either permit or prohibit tobacco sales by alcohol-licensed venues (0.65 and 1.73 percentage points, respectively). Increasing the minimum age of legal supply of tobacco products substantially reduces adolescent initiation, but has minimal impact on smoking prevalence in the adult population over the simulation period. Sustained reductions in antismoking advertising exposure of 50% and 100% from 2018 increase projected adult daily smoking prevalence in 2037 by 0.88 and 1.98 percentage points, respectively. CONCLUSIONS: These results suggest that any prudent approach to endgame planning should seek to build on rather than replace existing tobacco control measures that have proved effective to date. Additional interventions that can promote cessation are expected to be more successful in reducing smoking prevalence than interventions focussing exclusively on preventing initiation.

Asthma in urban Aboriginal children: A cross-sectional study of socio-demographic patterns and associations with pre-natal and current carer smoking.

AIM: To describe socio-demographic patterns of asthma prevalence in urban Aboriginal children and quantify associations between asthma prevalence and pre-natal maternal and current carer smoking. METHODS: Analyses used carer-reported survey data for 1290 urban Aboriginal children aged 2-17 years from the Study of Environment on Aboriginal Resilience and Child Health. Multilevel log-binomial regression was used to estimate asthma prevalence ratios (PRs) for child- and family-level socio-demographic factors, pre-natal maternal smoking and current carer smoking. Smoking-related PRs were compared with general-population estimates derived from meta-analyses of published cross-sectional data. RESULTS: Overall, 33.9% of children had ever had asthma, and 12.9% had received treatment for asthma in the past month. Prevalence estimates declined with increasing household income and increasing household size (posterior probabilities of decreasing trend >0.98), while children exposed to pre-natal maternal smoking had a higher risk of asthma ever than unexposed children (PR 1.18 (95% credible interval 1.00-1.40)). Recently treated asthma prevalence was not significantly associated with pre-natal maternal (0.98 (0.71-1.41)) or current carer smoking (0.97 (0.68-1.37)); however, there was substantial uncertainty in our PR estimates, and 95% credible intervals contained general-population estimates derived from the meta-analyses (1.37 (1.17-1.65) for pre-natal smoking, 1.28 (1.15-1.44) for current parental or household smoking). CONCLUSION: Among urban Aboriginal children in the Study of Environment on Aboriginal Resilience and Child Health cohort, asthma prevalence declines as household income and household size increase, while children exposed to pre-natal maternal smoking are at increased risk of ever having asthma. Our results emphasise the importance of reducing smoking in Aboriginal communities, particularly among pregnant women.

Access to Subsidized Smoking Cessation Medications by Australian Smokers Aged 45 Years and Older: A Population-Based Cohort Study.

INTRODUCTION: The principal aim of this study was to assess the accessibility of subsidized cessation medications to socioeconomically disadvantaged smokers, including smokers living in regional and remote communities. METHODS: Analyses used baseline questionnaire and linked Pharmaceutical Benefits Scheme data for 18 686 regular smokers participating in the 45 and Up Study, a large-scale Australian cohort study of people aged 45 years and older. Participants who were dispensed nicotine replacement therapy, varenicline, or bupropion were identified from the Pharmaceutical Benefits Scheme data, which provide an essentially complete record of participants' access to subsidized pharmaceuticals. Associations between the supply of each pharmacotherapy and a range of sociodemographic and health-related variables were evaluated using multiple logistic regression. RESULTS: The odds that participants were supplied with a cessation medication declined markedly with increasing age for participants older than 60 years and were substantially higher for participants who smoked 20 or more cigarettes/day than for participants who smoked fewer than 10 cigarettes/day. Participants with no formal qualification and those residing in socioeconomically disadvantaged areas had higher odds of receiving nicotine replacement therapy or varenicline than university-educated participants and participants living in the least disadvantaged areas. There was no evidence that participants residing in regional and remote communities had lower odds of receiving a cessation medication than participants residing in major cities. CONCLUSIONS: Older Australian smokers' access to cessation pharmacotherapies is determined predominantly by age and daily cigarette consumption and does not appear to be limited by educational achievement, socioeconomic disadvantage, or remoteness. IMPLICATIONS: Promoting the use of cessation medications is a principal measure proposed to achieve Australia's National Tobacco Strategy 2012-2018 goal of reducing cigarette consumption among socioeconomically disadvantaged smokers. The results of this large-scale cohort study indicate that access to cessation pharmacotherapies is determined primarily by age and daily cigarette consumption, and is not limited by socioeconomic circumstances, providing some reassurance that existing government subsidies are sufficient to ensure that pharmaceutical aids are accessible to all Australian smokers.

Phylogeny and divergence times of Australian Sphenomorphus group skinks (Scincidae, Squamata).

The Australian Sphenomorphus group is a diverse clade (c. 250 species) of scincid lizards (skinks) incorporating more than half of the Australian scincid fauna. Previous phylogenetic analyses of mitochondrial and nuclear gene sequence data for selected Australian Sphenomorphus group scincids have provided support for several morphologically- and ecologically-distinct clades; however, the relationships among these clades are only incompletely resolved. This paper presents a new phylogenetic analysis of the Australian Sphenomorphus group, based on nucleotide sequences for three regions of the mitochondrial genome and four nuclear genes (5645 aligned sites in total). Phylogenies generated using standard concatenation and multi-species coalescent approaches are generally similar, and nearly all conflicting nodes are weakly supported. Monophyly of a number of genera and other (informal) supra-specific taxa, including Calyptotis, Ctenotus, Eremiascincus, Hemiergis, Lerista, Notoscincus, the 'Eulamprus' quoyii group, and the 'Glaphyromorphus' crassicaudis group is well supported in all analyses. There is significant support for a clade including the 'Eulamprus' tenuis group, Gnypetoscincus, and Nangura, and a clade comprising Coeranoscincus, Coggeria, Ophioscincus, and Saiphos receives at least marginal support (posterior probabilities above 0.93). All analyses indicate that Anomalopus is polyphyletic, although topology tests suggest that support for this result is equivocal. Divergence times inferred using relaxed molecular clock methods are consistent with an Oligocene origin of the Australian Sphenomorphus group following trans-oceanic dispersal from Asia. Age estimates for clades distributed primarily in arid habitats (c. 9-17 million years) are generally younger than those for clades occurring in mesic environments (c. 15-22 million years); however, arid-zone clades are substantially more diverse, including nearly 80% of all Australian Sphenomorphus group scincids. This pattern conforms well with reconstructions of Australian palaeo-environments during the Cenozoic, which indicate a progressive shift from widespread mesic habitats in the Early Miocene (prior to 16 Mya) to predominantly arid environments 4-2 Mya.

Tracheo-oesophageal fistula (TOF) and oesophageal atresia (OA).

Tracheo-oesophageal fistula (TOF) and oesophageal atresia (OA) represent a series of anatomical abnormalities presenting for emergency surgery in the neonatal period. They present the anaesthetist with cardio-respiratory challenges in the preoperative, intra-operative and postoperative phases. In addition to the consequences of the pathology itself, co-morbidities are very common, which superimpose further considerations. The basic science, anatomy and genetics are discussed as well as the clinical presentation, perioperative management, controversies and complications. The evidence for optimum management is based mostly on expert opinion; there are very few large randomised controlled trials concerning many areas of perioperative management.

Clinically unrecognized intravascular placement of epidural catheter in a child--an argument for the use of radio-opaque contrast?

An epidural catheter was inserted after induction of anesthesia in a 28.2 kg 9-year-old boy scheduled to undergo bilateral femoral varus derotational osteotomies. There was no gravity free flow of blood down the catheter and there was no blood aspirated with a 2 ml syringe. After a negative test dose of a 4 ml solution of 0.25% levobupivacaine with epinephrine 1 : 200 000, a further 8 ml was administered via the epidural catheter. No significant increase in heart rate was noted. On surgical skin incision the heart rate increased from 94 to 116 b.min(-1) and blood pressure increased from 104/44 to 116/46 mmHg. A further 3 ml 0.25% levobupivacaine with epinephrine and clonidine 2 mug.kg(-1) were administered via the epidural catheter. The operation continued uneventfully although it was noted that the heart rate increased intermittently during the procedure. In view of the unexplained tachycardia and a history of cerebral palsy with the potential for postoperative muscle spasms, it was felt important to have a reliable epidural. To confirm placement, 2 ml of Isovue 300 (Iopamidol) was administered via the epidural catheter. X-ray screening demonstrated intravascular placement and the rapid disappearance of contrast. The catheter was removed and reinserted. Contrast demonstrated good spread in the epidural space. The merits of screening with contrast for epidural catheter placement in children are discussed.

The effects of caudal local anesthesia blockade on the Bispectral Index during general anesthesia in children.

BACKGROUND: Peripheral deafferentation induced by epidural or spinal anesthesia reduces the degree of cortical arousal in adults. This study aimed at determining if caudal blockade decreases the level of arousal, as measured by Bispectral Index (BIS) in unstimulated children, and to determine if this effect differed between age groups. METHODS: Hospital ethics committee approval and parental consent was obtained. Children (age between 24 months and 5 years) and infants (between 6 and 24 months of age) were recruited if they were scheduled for below umbilical surgery that would usually require caudal local anesthesia blockade. Before the procedure, subjects within each age group were randomized to either caudal group (1 ml.kg(-1) 0.25% bupivacaine), or control group (no caudal). In all groups, anesthesia was induced with sevoflurane and maintained at a constant endtidal concentration of 1.5% sevoflurane without N(2)O. Five minutes after induction a baseline BIS was recorded (BIS(1)). In the caudal groups, a caudal block was then performed while in the control groups no block was performed. Fifteen minutes later, the BIS was again recorded (BIS(2)). The change in BIS over this time period was the primary outcome (BIS(Delta)). After measurement, subjects in the control groups received a caudal block before the start of surgery. RESULTS: Twenty-nine infants and 18 children completed the study protocol. In children, BIS(Delta) was significantly different between the caudal group and control (-5.7 vs -0.7, P = 0.04). In infants, no significant difference was detected in BIS(Delta) between caudal and control groups. CONCLUSIONS: Caudal blockade decreased the degree of arousal, as measured by BIS, in unstimulated children aged 2-5 years. No change in arousal was detected in infants.