Costs associated with gunshot wounds in Canada in 1991.

OBJECTIVE: To estimate the costs (in 1993 dollars) associated with gunshot wounds in Canada in 1991. DESIGN: Cost analysis using separate estimates of gunshot incidence rates and costs per incident for victims who died, those who survived and were admitted to hospital and those who survived and were treated and released from emergency departments. Estimates were based on costs for medical care, mental health care, public services (i.e., police investigation), productivity losses, funeral expenses, and individual and family pain, suffering and lost quality of life. SETTING: Canada. OUTCOME MEASURES: Costs per case, costs by type of incident (e.g., assault, suicide or unintentional shooting) and costs per capita. RESULTS: The total estimated cost associated with gunshot wounds was $6.6 billion. Of this, approximately $63 million was spent on medical and mental health care and $10 million on public services. Productivity losses exceeded $1.5 billion. The remaining cost represented the value attributed to pain, suffering and lost quality of life. Suicides and attempted suicides accounted for the bulk of the costs ($4.7 billion); homicides and assaults were the next most costly ($1.1 billion). The cost per survivor admitted to hospital was approximately $300,000; this amount included just over $29,000 for medical and mental health care. CONCLUSION: Costs associated with gunshot wounds were $235 per capita in Canada in 1991, as compared with $595 in the United States in 1992. The differences in these costs may be due to differences in gun availability in the two countries. This suggests that increased gun control may reduce Canada''s costs, especially those related to suicide.     

Predicted range expansion of Chinese tallow tree (Triadica sebifera) in forestlands of the southern United States

Aim We present an integrated approach for predicting future range expansion of an invasive species (Chinese tallow tree) that incorporates statistical forecasting and analytical techniques within a spatially explicit, agent‐based, simulation framework. Location East Texas and Louisiana, USA. Methods We drew upon extensive field data from the US Forest Service and the US Geological Survey to calculate spread rate from 2003 to 2008 and to parameterize logistic regression models estimating habitat quality for Chinese tallow within individual habitat cells. We applied the regression analyses to represent population spread rate as a function of habitat quality, integrated this function into a logistic model representing local spread, and coupled this model with a dispersal model based on a lognormal kernel within the simulation framework. We simulated invasions beginning in 2003 based on several different dispersal velocities and compared the resulting spatial patterns to those observed in 2008 using cross Mantel’s tests. We then used the best dispersal velocity to predict range expansion to the year 2023. Results Chinese tallow invasion is more likely in low and flat areas adjacent to water bodies and roads, and less likely in mature forest stands and in pine plantations where artificial regeneration by planting seedlings is used. Forecasted invasions resulted in a distribution that extended from the Gulf Coast of Texas and Louisiana northward and westward as much as 300 km, representing approximately 1.58 million ha. Main conclusions Our new approach of calculating time series projections of annual range expansion should assist land managers and restoration practitioners plan proactive management strategies and treatments. Also, as field sampling continues on the national array of FIA plots, these new data can be incorporated easily into the present model, as well as being used to develop and/or improve models of other invasive plant species.     

Rainfall facilitates the spread, and time alters the impact, of the invasive Argentine ant

Climate change may exacerbate invasions by making conditions more favorable to introduced species relative to native species. Here we used data obtained during a long-term biannual survey of the distribution of ant species in a 481-ha preserve in northern California to assess the influence of interannual variation in rainfall on the spread of invasive Argentine ants, Linepithema humile, and the displacement of native ant species. Since the survey began in 1993, Argentine ants have expanded their range into 74 new hectares. Many invaded hectares were later abandoned, so the range of Argentine ants increased in some years and decreased in others. Rainfall predicted both range expansion and interannual changes in the distribution of Argentine ants: high rainfall, particularly in summer months, promoted their spread in the summer. This suggests that an increase in rainfall will promote a wider distribution of Argentine ants and increase their spread into new areas in California. Surprisingly, the distribution of two native ant species also increased following high rainfall, but only in areas of the preserve that were invaded by L. humile. Rainfall did not have a negative impact on total native ant species richness in invaded areas. Instead, native ant species richness in invaded areas increased significantly over the 13 years of observation. This suggests that the impact of Argentine ants on naïve ant communities may be most severe early in the invasion process.     

Comparing methods for measuring the rate of spread of invading populations

Measuring rates of spread during biological invasions is important for predicting where and when invading organisms will spread in the future as well as for quantifying the influence of environmental conditions on invasion speed. While several methods have been proposed in the literature to measure spread rates, a comprehensive comparison of their accuracy when applied to empirical data would be problematic because true rates of spread are never known. This study compares the performances of several spread rate measurement methods using a set of simulated invasions with known theoretical spread rates over a hypothetical region where a set of sampling points are distributed. We vary the density and distribution (aggregative, random, and regular) of the sampling points as well as the shape of the invaded area and then compare how different spread rate measurement methods accommodate these varying conditions. We find that the method of regressing distance to the point of origin of the invasion as a function of time of first detection provides the most reliable method over adverse conditions (low sampling density, aggregated distribution of sampling points, irregular invaded area). The boundary displacement method appears to be a useful complementary method when sampling density is sufficiently high, as it provides an instantaneous measure of spread rate, and does not require long time series of data.     

Patterns and Pathways in the Post-Establishment Spread of Non-Indigenous Aquatic Species: The Slowing Invasion of North American Inland Lakes by the Zebra Mussel

The zebra mussel, Dreissena polymorpha, has spread through eastern North American aquatic ecosystems during the past 15 years. Whereas spread among navigable waterways was rapid, the invasion of isolated watersheds has progressed more slowly and less predictably. We examined the patterns of overland spread over multiple spatial and temporal extents including individual lake districts, states, and multi-state regions in the USA and found that only a small proportion (<8%) of suitable inland lakes have been invaded, with the rate of invasion appearing to be slowing. Of the 293 lakes known to be invaded, 97% are located in states adjacent to the Laurentian Great Lakes with over half located in Michigan. Only six states have more than 10 invaded lakes and only in Michigan and Indiana have more than 10% of suitable lakes become invaded. At smaller spatial extents, invaded lakes are often clustered within a lake-rich region across southern Michigan and northern Indiana. This clustering appears primarily due to multiple overland invasions originating from the Great Lakes followed to a lesser extent by subsequent secondary overland and downstream dispersal. Downstream spread appears responsible for only one third of the inland invasions. Temporally, invasions peaked in the late 1990s, with only 13 new invasions (0.4% of suitable lakes) reported in 2003 in the four-state region surrounding Lake Michigan. Peak rates of invasion occurred 4–6 years earlier in Michigan relative to Indiana and Wisconsin, but this time lag is likely due to differences in the establishment of Great Lake source populations rather than ‘stepping stone’ dispersal across the landscape.     

Characterised and Projected Costs of Nonindigenous Species in Canada

Biological invasions by nonindigenous species (NIS) can have adverse effects on economically important goods and services, and sometimes result in an ‘invisible tax’ on natural resources (e.g. reduced yield). The combined economic costs of NIS may be significant, with implications for environmental policy and resource management; yet economic impact assessments are rare at a national scale. Impacts of nuisance NIS may be direct (e.g. loss of hardwood trees) or indirect (e.g. alteration of ecosystem services provided by growing hardwoods). Moreover, costs associated with these effects may be accrued to resources and services with clear ‘market’ values (e.g. crop production) and to those with more ambiguous, ‘non-market’ values (e.g. aesthetic value of intact forest). We characterised and projected economic costs associated with nuisance NIS in Canada, through a combination of case-studies and an empirical model derived from 21 identified effects of 16 NIS. Despite a severe dearth of available data, characterised costs associated with ten NIS in Canadian fisheries, agriculture and forestry totalled $187 million Canadian (CDN) per year. These costs were dwarfed by the ‘invisible tax’ projected for sixteen nuisance NIS found in Canada, which was estimated at between $13.3 and $34.5 billion CDN per year. Canada remains highly vulnerable to new nuisance NIS, but available manpower and financial resources appear insufficient to deal with this problem. An erratum to this article is available at .     

Incentivizing the Public to Support Invasive Species Management: Eurasian Milfoil Reduces Lakefront Property Values

Economic evaluations of invasive species are essential for providing comprehensive assessments of the benefits and costs of publicly-funded management activities, yet many previous investigations have focused narrowly on expenditures to control spread and infestation. We use hedonic modeling to evaluate the economic effects of Eurasian milfoil (Myriophyllum spicatum) invasions on lakefront property values of single-family homes in an urban-suburban landscape. Milfoil often forms dense canopies at the water surface, diminishing the value of ecosystem services (e.g., recreation, fishing) and necessitating expensive control and management efforts. We compare 1,258 lakeshore property sale transactions (1995–2006) in 17 lakes with milfoil and 24 un-invaded lakes in King County, Washington (USA). After accounting for structural (e.g., house size), locational (e.g., boat launch), and environmental characteristics (e.g., water clarity) of lakes, we found that milfoil has a significant negative effect on property sales price ($94,385 USD lower price), corresponding to a 19% decline in mean property values. The aggregate cost of milfoil invading one additional lake in the study area is, on average, $377,542 USD per year. Our study illustrates that invasive aquatic plants can significantly impact property values (and associated losses in property taxes that reduce local government revenue), justifying the need for management strategies that prevent and control invasions. We recommend coordinated efforts across Lake Management Districts to focus institutional support, funding, and outreach to prevent the introduction and spread of milfoil. This effort will limit opportunities for re-introduction from neighboring lakes and incentivize private landowners and natural resource agencies to commit time and funding to invasive species management.     

Costs Analysis of a Population Level Rabies Control Programme in Tamil Nadu,India

The study aimed to determine costs to the state government of implementing different interventions for controlling rabies among the entire human and animal populations of Tamil Nadu. This built upon an earlier assessment of Tamil Nadu''s efforts to control rabies. Anti-rabies vaccines were made available at all health facilities. Costs were estimated for five different combinations of animal and human interventions using an activity-based costing approach from the provider perspective. Disease and population data were sourced from the state surveillance data, human census and livestock census. Program costs were extrapolated from official documents. All capital costs were depreciated to estimate annualized costs. All costs were inflated to 2012 Rupees. Sensitivity analysis was conducted across all major cost centres to assess their relative impact on program costs. It was found that the annual costs of providing Anti-rabies vaccine alone and in combination with Immunoglobulins was $0.7 million (Rs 36 million) and $2.2 million (Rs 119 million), respectively. For animal sector interventions, the annualised costs of rolling out surgical sterilisation-immunization, injectable immunization and oral immunizations were estimated to be $ 44 million (Rs 2,350 million), $23 million (Rs 1,230 million) and $ 11 million (Rs 590 million), respectively. Dog bite incidence, health systems coverage and cost of rabies biologicals were found to be important drivers of costs for human interventions. For the animal sector interventions, the size of dog catching team, dog population and vaccine costs were found to be driving the costs. Rabies control in Tamil Nadu seems a costly proposition the way it is currently structured. Policy makers in Tamil Nadu and other similar settings should consider the long-term financial sustainability before embarking upon a state or nation-wide rabies control programme.     

Optimal surveillance and eradication of invasive species in heterogeneous landscapes

Cost-effective surveillance strategies are needed for efficient responses to biological invasions and must account for the trade-offs between surveillance effort and management costs. Less surveillance may allow greater population growth and spread prior to detection, thereby increasing the costs of damages and control. In addition, surveillance strategies are usually applied in environments under continual invasion pressure where the number, size and location of established populations are unknown prior to detection. We develop a novel modeling framework that accounts for these features of the decision and invasion environment and determines the long term sampling effort that minimises the total expected costs of new invasions. The optimal solution depends on population establishment and growth rates, sample sensitivity, and sample, eradication, and damage costs. We demonstrate how to optimise surveillance systems under budgetary constraints and find that accounting for spatial heterogeneity in sampling costs and establishment rates can greatly reduce management costs.     

A valuable tree by gum!

Which majestic ornamental tree, conspicuous in the Australian landscape, has ten million hectares in cultivation worldwide--yielding timber, fuel, essential oil and cut foliage? It could only be eucalyptus.     

Screening for hypercholesterolemia among Canadians: how much will it cost?

OBJECTIVE: To determine the cost of screening all Canadians aged 30 years or more without coronary heart disease (CHD) for hypercholesterolemia. DATA SOURCES: The expected results of initial screening of the serum cholesterol level were estimated on the basis of 1986 Canadian census data and the 1978 Canada Health Survey. The results of repeat testing were estimated on the basis of data from the Lipid Research Clinics Prevalence Study. Lipid profile results were extrapolated from tests at the Montreal General Hospital''s clinical chemistry laboratory. Laboratory costs and primary care practitioner costs were provided by the Canadian Society of Clinical Chemists and provincial fee schedules respectively. MAIN RESULTS: Among 12,479,356 Canadians free of CHD 48.7% would be identified as being at high risk, 4.8% would be identified as being at moderate risk, and 46.6% would be reassured that their lipid risk for CHD was low. The total cost of implementing the program in the first year would be $432 million to $561 million ($325 million for laboratory tests and $107 million to $236 million for visits to primary care practitioners). CONCLUSION: The substantial cost of implementing a nationwide screening program must be weighed against the expected benefits to ensure that the final result is both practical and economically feasible.     

Reduced vertebrate diversity independent of spatial scale following feral swine invasions

Biological invasions often have contrasting consequences with reports of invasions decreasing diversity at small scales and facilitating diversity at large scales. Thus, previous literature has concluded that invasions have a fundamental spatial scale‐dependent relationship with diversity. Whether the scale‐dependent effects apply to vertebrate invaders is questionable because studies consistently report that vertebrate invasions produce different outcomes than plant or invertebrate invasions. Namely, vertebrate invasions generally have a larger effect size on species richness and vertebrate invaders commonly cause extinction, whereas extinctions are rare following invertebrate or plant invasions. In an agroecosystem invaded by a non‐native ungulate (i.e., feral swine, Sus scrofa), we monitored species richness of native vertebrates in forest fragments ranging across four orders of magnitude in area. We tested three predictions of the scale‐dependence hypothesis: (a) Vertebrate species richness would positively increase with area, (b) the species richness y‐intercept would be lower when invaded, and (c) the rate of native species accumulation with area would be steeper when invaded. Indeed, native vertebrate richness increased with area and the species richness was 26% lower than should be expected when the invasive ungulate was present. However, there was no evidence that the relationship was scale dependent. Our data indicate the scale‐dependent effect of biological invasions may not apply to vertebrate invasions.     

Time,space, place,and the Bonn Challenge global forest restoration target

The Bonn Challenge, a global effort to begin restoring 350 million hectares of degraded forest landscapes by 2030, was launched in 2011. To date countries have committed to restore more than 60 million hectares as part of the Bonn Challenge. As global decision‐makers, governments, and communities join the effort to restore degraded land, new questions about the economics of restoration have emerged. Critics argue that restoration takes too long, costs too much, and produces too few benefits to justify public or private expenditures. This paper addresses these concerns by presenting a methodology for valuing the net benefits of large‐scale ecosystem restoration initiatives by estimating the net benefit of achieving the Bonn Challenge. This paper also estimates the net benefit of achieving the Bonn Challenge restoration target under different social discounting regimes, different valuations of public goods, and different time horizons to see how they affect the argument for investing society's scarce resources in restoration. The results suggest that achieving the Bonn Challenge would generate a net benefit of between U.S.$0.7 and U.S.$9 trillion. The results show that restoration can create benefits that exceed its costs and that the value of these benefits might differ depending on the discount rate. The results show that lower social discount rates correspond to higher restoration rates. This suggests that the Bonn Challenge target is more likely to be met when a low social discount rate is used to discount the benefits and costs of restoration.     

Its all about connections: hubs and invasion in habitat networks

During the early stages of invasion, the interaction between the features of the invaded landscape, notably its spatial structure, and the internal dynamics of an introduced population has a crucial impact on establishment and spread. By approximating introduction areas as networks of patches linked by dispersal, we characterised their spatial structure with specific metrics and tested their impact on two essential steps of the invasion process: establishment and spread. By combining simulations with experimental introductions of Trichogramma chilonis (Hymenoptera: Trichogrammatidae) in artificial laboratory microcosms, we demonstrated that spread was hindered by clusters and accelerated by hubs but was also affected by small‐population mechanisms prevalent for invasions, such as Allee effects. Establishment was also affected by demographic mechanisms, in interaction with network metrics. These results highlight the importance of considering the demography of invaders as well as the structure of the invaded area to predict the outcome of invasions.     

Current and projected annual direct costs of screening asymptomatic men for prostate cancer using prostate-specific antigen

BACKGROUND: Concern over the cost of screening for asymptomatic prostate cancer by means of prostate-specific antigen (PSA) testing has played an important role in PSA screening policy. However, little is known about the true costs of current PSA screening in Canada and how costs may change in the future. METHODS: The authors performed a cost identification study from the perspective of provincial ministries of health. They used data from published reports, hospital discharge data, claims data from several provinces, a laboratory survey, a national survey of knowledge, attitudes and beliefs about screening, a provincial cancer registry and expert opinion to estimate current first-year screening costs. Using demographic data from Statistics Canada and various scenarios regarding changes in screening patterns, the authors derived estimates of the future costs of PSA screening. RESULTS: In 1995 PSA screening cost an estimated $45 million (range $40 million to $84 million). Treatment accounted for over 61% of total costs, whereas screening, diagnosis and staging accounted for 35%. Screening all eligible men in Canada in 1995 would have cost $317 million (range $356 million to $691 million), more than the costs of all prostate cancer care in that year. Annual recurrent screening for all eligible men in 2005 would cost $219 million (range $208 million to $412 million). Projections from existing trends suggest that annual costs of PSA screening in 2000 are likely to increase from the estimated $45 million to approximately $66 million (range $59 million to $126 million). INTERPRETATION: PSA screening is costly, but even universal screening would consume a smaller share of national health expenditures than previous studies have suggested. Costs attributable to PSA screening may increase in the future owing to changes in utilization patterns and demographic shifts.     

Long-term costs and health impact of continued global fund support for antiretroviral therapy

Background

By the end of 2011 Global Fund investments will be supporting 3.5 million people on antiretroviral therapy (ART) in 104 low- and middle-income countries. We estimated the cost and health impact of continuing treatment for these patients through 2020.

Methods and Findings

Survival on first-line and second-line ART regimens is estimated based on annual retention rates reported by national AIDS programs. Costs per patient-year were calculated from country-reported ARV procurement prices, and expenditures on laboratory tests, health care utilization and end-of-life care from in-depth costing studies. Of the 3.5 million ART patients in 2011, 2.3 million will still need treatment in 2020. The annual cost of maintaining ART falls from $1.9 billion in 2011 to $1.7 billion in 2020, as a result of a declining number of surviving patients partially offset by increasing costs as more patients migrate to second-line therapy. The Global Fund is expected to continue being a major contributor to meeting this financial need, alongside other international funders and domestic resources. Costs would be $150 million less in 2020 with an annual 5% decline in first-line ARV prices and $150–370 million less with a 5%–12% annual decline in second-line prices, but $200 million higher in 2020 with phase out of stavudine (d4T), or $200 million higher with increased migration to second-line regimens expected if all countries routinely adopted viral load monitoring. Deaths postponed by ART correspond to 830,000 life-years saved in 2011, increasing to around 2.3 million life-years every year between 2015 and 2020.

Conclusions

Annual patient-level direct costs of supporting a patient cohort remain fairly stable over 2011–2020, if current antiretroviral prices and delivery costs are maintained. Second-line antiretroviral prices are a major cost driver, underscoring the importance of investing in treatment quality to improve retention on first-line regimens.     

Economics of microsurgical cases and routine cases in a medical center

This report describes the economic impact of microsurgical cases and routine plastic surgery cases in our medical center. The study is based on a financial analysis of the practices of two surgeons. Financial data of patient encounters (admission to the hospital or a surgical unit) identified with each surgeon were categorized into microsurgical and related cases and routine cases (including cosmetic procedures and general hand cases). Revenues, costs, and profits were tabulated. Data were analyzed for 2 fiscal years (1994-95 and 1995-96). Analysis of the first fiscal year showed that microsurgery encounters (n = 188) generated $4.4 million in revenue with a profit margin after direct costs of $2.5 million (57 percent) and a net profit, after indirect costs, of $1 million (23 percent). Routine encounters (n = 262) generated $1.7 million with a net loss of -$145,000 after direct and indirect costs. In the second fiscal year, microsurgery encounters (n = 230) had income of $4.7 million, a profit over direct costs of $2.5 million (53 percent), and a net profit after indirect costs of $0.9 million (19 percent). Routine cases (n = 202) in the same period earned $1.3 million with a net loss of -$107,000. This analysis formulates a comprehensive definition of microsurgical practice and shows that cases within this definition generated dramatically higher hospital incomes and profits compared with routine plastic surgical practice. In the circumstances of our medical center, development of this subspecialty is fiscally justifiable.     

Estimating the economic costs of algal blooms in the Canadian Lake Erie Basin

Over the past two decades there has been a re-emergence of regular harmful algal blooms in Lake Erie due to increasing phosphorus loading, mainly from non-point agricultural sources. The Canadian and United States governments have jointly agreed to reduce phosphorus loadings to the lake in order to control the extent and severity of the blooms. Citizens on both sides of the border face a number of economic costs, both market and non-market, as a result of the blooms. This study values these costs for the Canadian portion of the Lake Erie basin economy using standard economic approaches that are widely applied within the world of cost-benefit analysis. The results suggest that algal blooms will impose equivalent annual costs equal to $272 million in 2015 prices over a 30-year period if left unchecked. The largest market costs will be imposed on the tourism industry ($110 million in equivalent annual costs) and the largest non-market costs will be borne by recreational users and those who place inherent value on the lake’s quality ($115 million in equivalent annual costs). Management action to reduce phosphorus loadings is found to be justified on economic grounds if the 30-year net present value of the reduction program is less than $1294 million (2015 Canadian dollars).     

Offense and defense in landscape-level invasion control

Biological invasions are multi-stage processes comprising chance demographic events, species interactions, and dispersal. Despite this complexity, simple models can increase understanding of the invasion process. We model the spread of aquatic invasive species through a network of lakes to evaluate the effectiveness of two intervention strategies. The first, which we call offense, contains the invader at sources; the second, which we call defense, protects uninvaded destinations. Deterministic models reveal the effects of these intervention strategies on spread rates. Practical applications involve finite collections of uninvaded lakes, however, and we therefore also present a stochastic model to describe how these strategies affect expected times to important invasion milestones. When the goal is to reduce overall spread rates, both approaches agree that offense is better early in invasions, but that defense is better after 1/2 the lakes are invaded. When the goal is to protect areas of high conservation value, however, defensive site protection always provides lower per site introduction rates. Although we focus on lakes, our results are quite general, and could be applied to any discrete habitat patches including, for example, fragmented terrestrial habitats.     

Do non-native earthworms in Southeast Alaska use streams as invasional corridors in watersheds harvested for timber?

Exotic earthworms from Europe and Asia have invaded previously earthworm-free areas of North America where they consume leaf litter, mix soil horizons, and alter nutrient cycling. Primarily, earthworm introductions occur through human activities; we hypothesized that the combination of logging (i.e., road construction and soil disturbance) and stream transport (i.e., hydrochory) allows earthworms to invade new ecosystems and spread within watersheds. On Prince of Wales Island, AK, we surveyed riparian zones in 11 watersheds with varying timber harvest intensity for terrestrial oligochaetes. Additionally, common invasive earthworms were experimentally submerged in a local stream to test for tolerance to prolonged immersion: all taxa survived immersion for at least 6 days. Using principal components analysis, watershed and harvest variables describing the watersheds upstream of our sampled riparian areas were reduced to two principal components describing harvest intensity (PC1) and harvest style (PC2). Logistic models successfully predicted earthworm abundance (r ²  = 0.70) from PC1, which indicated that watersheds with older, intense upstream timber harvest contained larger earthworm populations. Earthworm species richness was best predicted by PC2 (r ²  = 0.39), which suggested that earthworm communities in watersheds containing large clear-cut stands were more species-rich. Collectively, these results suggest that (1) invasive earthworms may use streams for dispersal and (2) upstream introductions via timber harvest can initiate downstream earthworm invasions. Hydrochory would allow invasive earthworms to spread at rates (tens of km d⁻¹) that are much greater than previously reported rates of terrestrial spread (5–10 m y⁻¹). Effective control of exotic earthworms in riparian zones will require watershed-level management and surveillance.