Genetic sampling for estimating density of common species

Understanding population dynamics requires reliable estimates of population density, yet this basic information is often surprisingly difficult to obtain. With rare or difficult‐to‐capture species, genetic surveys from noninvasive collection of hair or scat has proved cost‐efficient for estimating densities. Here, we explored whether noninvasive genetic sampling (NGS) also offers promise for sampling a relatively common species, the snowshoe hare (Lepus americanus Erxleben, 1777), in comparison with traditional live trapping. We optimized a protocol for single‐session NGS sampling of hares. We compared spatial capture–recapture population estimates from live trapping to estimates derived from NGS, and assessed NGS costs. NGS provided population estimates similar to those derived from live trapping, but a higher density of sampling plots was required for NGS. The optimal NGS protocol for our study entailed deploying 160 sampling plots for 4 days and genotyping one pellet per plot. NGS laboratory costs ranged from approximately $670 to $3000 USD per field site. While live trapping does not incur laboratory costs, its field costs can be considerably higher than for NGS, especially when study sites are difficult to access. We conclude that NGS can work for common species, but that it will require field and laboratory pilot testing to develop cost‐effective sampling protocols.     

An empirical analysis of the cost of rearing dairy heifers from birth to first calving and the time taken to repay these costs

Rearing quality dairy heifers is essential to maintain herds by replacing culled cows. Information on the key factors influencing the cost of rearing under different management systems is, however, limited and many farmers are unaware of their true costs. This study determined the cost of rearing heifers from birth to first calving in Great Britain including the cost of mortality, investigated the main factors influencing these costs across differing farming systems and estimated how long it took heifers to repay the cost of rearing on individual farms. Primary data on heifer management from birth to calving was collected through a survey of 101 dairy farms during 2013. Univariate followed by multivariable linear regression was used to analyse the influence of farm factors and key rearing events on costs. An Excel spreadsheet model was developed to determine the time it took for heifers to repay the rearing cost. The mean±SD ages at weaning, conception and calving were 62±13, 509±60 and 784±60 days. The mean total cost of rearing was £1819±387/heifer with a mean daily cost of £2.31±0.41. This included the opportunity cost of the heifer and the mean cost of mortality, which ranged from £103.49 to £146.19/surviving heifer. The multivariable model predicted an increase in mean cost of rearing of £2.87 for each extra day of age at first calving and a decrease in mean cost of £6.06 for each percentile increase in time spent at grass. The model also predicted a decrease in the mean cost of rearing in autumn and spring calving herds of £273.20 and £288.56, respectively, compared with that in all-year-round calving herds. Farms with herd sizes⩾100 had lower mean costs of between £301.75 and £407.83 compared with farms with <100 milking cows. The mean gross margin per heifer was £441.66±304.56 (range £367.63 to £1120.08), with 11 farms experiencing negative gross margins. Most farms repaid the cost of heifer rearing in the first two lactations (range 1 to 6 lactations) with a mean time from first calving until breaking even of 530±293 days. The results of the economic analysis suggest that management decisions on key reproduction events and grazing policy significantly influence the cost of rearing and the time it takes for heifers to start making a profit for the farm.     

Retention in Care and Outpatient Costs for Children Receiving Antiretroviral Therapy in Zambia: A Retrospective Cohort Analysis

Background

There are few published estimates of the cost of pediatric antiretroviral therapy (ART) in Africa. Our objective was to estimate the outpatient cost of providing ART to children remaining in care at six public sector clinics in Zambia during the first three years after ART initiation, stratified by service delivery site and time on treatment.

Methods

Data on resource utilization (drugs, diagnostics, outpatient visits, fixed costs) and treatment outcomes (in care, died, lost to follow up) were extracted from medical records for 1,334 children at six sites who initiated ART at <15 years of age between 2006 and 2011. Fixed and variable unit costs (reported in 2011 USD) were estimated from the provider’s perspective using site level data.

Results

Median age at ART initiation was 4.0 years; median CD4 percentage was 14%. One year after ART initiation, 73% of patients remained in care, ranging from 60% to 91% depending on site. The average annual outpatient cost per patient remaining in care was $209 (95% CI, $199–$219), ranging from $116 (95% CI, $107–$126) to $516 (95% CI, $499–$533) depending on site. Average annual costs decreased as time on treatment increased. Antiretroviral drugs were the largest component of all outpatient costs (>50%) at four sites. At the two remaining sites, outpatient visits and fixed costs together accounted for >50% of outpatient costs. The distribution of costs is slightly skewed, with median costs 3% to 13% lower than average costs during the first year after ART initiation depending on site.

Conclusions

Outpatient costs for children initiating ART in Zambia are low and comparable to reported outpatient costs for adults. Outpatient costs and retention in care vary widely by site, suggesting opportunities for efficiency gains. Taking advantage of such opportunities will help ensure that targets for pediatric treatment coverage can be met.     

Impact Assessment of an Independent Agency for Animal Health in England

The applicability of a stochastic model was explored to assess the impact of a new independent agency for animal health in England in terms of the cost of animal disease outbreaks. The new agency was proposed to take responsibility for animal disease management in England. The stochastic model estimates the likelihood that the proposed new agency would face animal disease outbreaks of major and minor magnitude; and how many outbreaks of each magnitude, within its first 30 years of operation. Large variability in the potential total cost of the new agency was attributable to the possibility of an outbreak of an unknown major disease, although Bluetongue, Foot and Mouth Disease, and Avian Influenza were also influential. The results show that if the new agency reduces disease costs by even 0.5%, this could benefit society by an estimated £21 million per year. The stochastic approach offers a method for dealing with uncertainties in any continuing deliberations regarding the proposed new agency, resulting in a potential annual gain of £73 million ranging to an annual loss of £144 million.     

Production of biocommodities and bioelectricity by cell‐free synthetic enzymatic pathway biotransformations: Challenges and opportunities

Cell‐free synthetic (enzymatic) pathway biotransformation (SyPaB) is the assembly of a number of purified enzymes (usually more than 10) and coenzymes for the production of desired products through complicated biochemical reaction networks that a single enzyme cannot do. Cell‐free SyPaB, as compared to microbial fermentation, has several distinctive advantages, such as high product yield, great engineering flexibility, high product titer, and fast reaction rate. Biocommodities (e.g., ethanol, hydrogen, and butanol) are low‐value products where costs of feedstock carbohydrates often account for ～30–70% of the prices of the products. Therefore, yield of biocommodities is the most important cost factor, and the lowest yields of profitable biofuels are estimated to be ca. 70% of the theoretical yields of sugar‐to‐biofuels based on sugar prices of ca. US$ 0.18 per kg. The opinion that SyPaB is too costly for producing low‐value biocommodities are mainly attributed to the lack of stable standardized building blocks (e.g., enzymes or their complexes), costly labile coenzymes, and replenishment of enzymes and coenzymes. In this perspective, I propose design principles for SyPaB, present several SyPaB examples for generating hydrogen, alcohols, and electricity, and analyze the advantages and limitations of SyPaB. The economical analyses clearly suggest that developments in stable enzymes or their complexes as standardized parts, efficient coenzyme recycling, and use of low‐cost and more stable biomimetic coenzyme analogs, would result in much lower production costs than do microbial fermentations because the stabilized enzymes have more than 3 orders of magnitude higher weight‐based total turn‐over numbers than microbial biocatalysts, although extra costs for enzyme purification and stabilization are spent. Biotechnol. Bioeng. 2010. 105: 663–677. © 2009 Wiley Periodicals, Inc.     

Determining the size of a total purchasing site to manage the financial risks of rare costly referrals: computer simulation model.

OBJECTIVE: To estimate the financial risks of 15 categories of rare costly referrals for total purchasing sites of different population sizes. DESIGN: Computer simulation of 100 fund years assuming Poisson distribution of referrals. SETTING: British general practices that have opted to become total purchasing sites. Referral rates and price estimates were supplied by South and West Devon Health Commission. MAIN OUTCOME MEASURES: Variation in referral costs to purchasers in relation to size of risk pool (person years at risk). RESULTS: Random variation in referral costs increased as the size of the risk pool decreased. Variation increased greatly below 30,000 person years. The mean simulated cost of the referral categories considered was 2.8% of total NHS hospital and community service costs, and the maximum simulated cost for 7000 person years was 6.8%. Simulated variation was robust to assumption about prices and referral rates for specific types of referral. CONCLUSION: Rare costly referrals seem unlikely to bankrupt total purchasing sites. The management of risk is not in itself justification for total purchasing to be based in several general practices in order to generate large populations. There are other ways of managing risk. Sites can easily explore options by simulations using local referral rates and prices.     

Halving the Cost of Anaesthetic Agents

A survey in South Wales has been used to estimate the annual cost of individual anaesthetic drugs used in the National Health Service. Halothane, costing £900,000, is the most expensive item, followed by oxygen (£390,000) and nitrous oxide (£350,000). The total cost of drugs used for hospital anaesthetics is estimated to be £2,300,000, and for dental anaesthetics £156,000. The drug cost of the average hospital anaesthetic is £1 3s. and of the average dental anaesthetic 1s. 9d.The provision of liquid oxygen stores could reduce oxygen costs by up to 90%, and the greater use of closed-circuit anaesthesia, with low gas flows, could save £750,000 annually. The drug cost of an anaesthetic in Cardiff has risen from 8s. 4d. in 1959 to 19s. 10d. in 1968, but costs in Cardiff compare favourably with published figures from other similar centres.     

Impacts of management practices on bioenergy feedstock yield and economic feasibility on Conservation Reserve Program grasslands

Perennial grass mixtures planted on Conservation Reserve Program (CRP) land are a potential source of dedicated bioenergy feedstock. Long‐term nitrogen (N) and harvest management are critical factors for maximizing biomass yield while maintaining the longevity of grass stands. A six‐year farm‐scale study was conducted to understand the impact of weather variability on biomass yield, determine optimal N fertilization and harvest timing management practices for sustainable biomass production, and estimate economic viability at six CRP sites in the United States. Precipitation during the growing season was a critical factor for annual biomass production across all regions, and annual biomass production was severely reduced when growing season precipitation was below 50% of average. The N rate of 112 kg ha^?1 produced the highest biomass yield at each location. Harvest timing resulting in the highest biomass yield was site‐specific and was a factor of predominant grass type, seasonal precipitation, and the number of harvests taken per year. The use of N fertilizer for yield enhancement unambiguously increased the cost of biomass regardless of the harvest timing for all six sites. The breakeven price of biomass at the farmgate ranged from $37 to $311 Mg^?1 depending on the rate of N application, timing of harvesting, and location when foregone opportunity costs were not considered. Breakeven prices ranged from $69 to $526 Mg^?1 when the loss of CRP land rental payments was included as an opportunity cost. Annual cost of the CRP to the federal government could be reduced by over 8% in the states included in this study; however, this would require the biomass price to be much higher than in the case where the landowner receives the CRP land rent. This field research demonstrated the importance of long‐term, farm‐scale research for accurate estimation of biomass feedstock production and economic viability from perennial grasslands.     

Economic Analysis of a School‐Based Obesity Prevention Program

Objective: To assess the cost‐effectiveness and cost‐benefit of Planet Health, a school‐based intervention designed to reduce obesity in youth of middle‐school age children. Research Methods and Procedures: Standard cost‐effectiveness analysis methods and a societal perspective were used in this study. Three categories of costs were measured: intervention costs, medical care costs associated with adulthood overweight, and costs of productivity loss associated with adulthood overweight. Health outcome was measured as cases of adulthood overweight prevented and quality‐adjusted life years (QALYs) saved. Cost‐effectiveness ratio was measured as the ratio of net intervention costs to the total number of QALYs saved, and net‐benefit was measured as costs averted by the intervention minus program costs. Results: Under base‐case assumptions, at an intervention cost of $33, 677 or $14 per student per year, the program would prevent an estimated 1.9% of the female students (5.8 of 310) from becoming overweight adults. As a result, an estimated 4.1 QALYs would be saved by the program, and society could expect to save an estimated $15, 887 in medical care costs and $25, 104 in loss of productivity costs. These findings translated to a cost of $4305 per QALY saved and a net saving of $7313 to society. Results remained cost‐effective under all scenarios considered and remained cost‐saving under most scenarios. Discussion: The Planet Health program is cost‐effective and cost‐saving as implemented. School‐based prevention programs of this type are likely to be cost‐effective uses of public funds and warrant careful consideration by policy makers and program planners.     

Virtual outreach: economic evaluation of joint teleconsultations for patients referred by their general practitioner for a specialist opinion

Objectives To test the hypotheses that, compared with conventional outpatient consultations, joint teleconsultation (virtual outreach) would incur no increased costs to the NHS, reduce costs to patients, and reduce absences from work by patients and their carers.Design Cost consequences study alongside randomised controlled trial.Setting Two hospitals in London and Shrewsbury and 29 general practices in inner London and Wales.Participants 3170 patients identified; 2094 eligible for inclusion and willing to participate. 1051 randomised to virtual outreach and 1043 to standard outpatient appointments.Main outcome measures NHS costs, patient costs, health status (SF-12), time spent attending index consultation, patient satisfaction.Results Overall six months costs were greater for the virtual outreach consultations (£724 per patient) than for conventional outpatient appointments (£625): difference in means £99 ($162; €138) (95% confidence interval £10 to £187, P=0.03). If the analysis is restricted to resource items deemed “attributable” to the index consultation, six month costs were still greater for virtual outreach: difference in means £108 (£73 to £142, P < 0.0001). In both analyses the index consultation accounted for the excess cost. Savings to patients in terms of costs and time occurred in both centres: difference in mean total patient cost £8 (£5 to £10, P < 0.0001). Loss of productive time was less in the virtual outreach group: difference in mean cost £11 (£10 to £12, P < 0.0001).Conclusion The main hypothesis that virtual outreach would be cost neutral is rejected, but the hypotheses that costs to patients and losses in productivity would be lower are supported.     

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.     

Upstroke wing flexion and the inertial cost of bat flight

Flying vertebrates change the shapes of their wings during the upstroke, thereby decreasing wing surface area and bringing the wings closer to the body than during downstroke. These, and other wing deformations, might reduce the inertial cost of the upstroke compared with what it would be if the wings remained fully extended. However, wing deformations themselves entail energetic costs that could exceed any inertial energy savings. Using a model that incorporates detailed three-dimensional wing kinematics, we estimated the inertial cost of flapping flight for six bat species spanning a 40-fold range of body masses. We estimate that folding and unfolding comprises roughly 44 per cent of the inertial cost, but that the total inertial cost is only approximately 65 per cent of what it would be if the wing remained extended and rigid throughout the wingbeat cycle. Folding and unfolding occurred mostly during the upstroke; hence, our model suggests inertial cost of the upstroke is not less than that of downstroke. The cost of accelerating the metacarpals and phalanges accounted for around 44 per cent of inertial costs, although those elements constitute only 12 per cent of wing weight. This highlights the energetic benefit afforded to bats by the decreased mineralization of the distal wing bones.     

Cost analysis of the Kozak protocol as used in an Ontario hospital in the treatment of children with epidermolysis bullosa.

Conventional treatment of epidermolysis bullosa is often unsuccessful. The Kozak protocol is an alternative that has been given considerable public support in Ontario. The incremental cost of this treatment program at the Hospital for Sick Children, Toronto, was examined. The departments of nursing, pharmacy and food services each kept records of salaries and supply costs applicable to the care of nine patients with epidermolysis bullosa who were treated in the fiscal year 1982-83. The selected direct costs to the hospital were compared with the projected costs if these patients had been treated in Dr. Kozak''s clinic in West Germany or under the financial arrangements offered to Dr. Kozak by the Ontario minister of health. At a total incremental cost of +255.92 per patient-day, care at the Hospital for Sick Children may not currently be the least expensive means of offering the Kozak protocol to Ontario children. However, the major expense of the program, the nurses'' salaries, could be reduced if the patients'' parents were to assume many of the nursing tasks; this would make the hospital''s program the most cost-effective method of treating children with epidermolysis bullosa.     

Eradicating Helicobacter pylori in Peptic Ulcer Disease Reduces Medical Costs in the Community

Background: Eradicating Helicobacter pylori markedly reduces ulcer recurrence in patients with peptic ulcer disease (PUD). Many decision analysis studies have concluded that eradicating H. pylori in PUD patients is more cost‐effective than maintaining antisecretory therapy. In 1995, we introduced an H. pylori eradication program into a large transportation company that experienced increased incidences of PUD among its employees along with increased medical costs, and we performed trend analysis of the actual medical costs of PUD in this cohort. Methods: In this cohort, there were approximately 8500 employees. H. pylori‐positive PUD patients were identified at the annual health check up. The patients received eradication therapy with lansoprazole, amoxicillin, and clarithromycin. After eradication, the patients were followed up by a yearly health check up. The annual number of patients who received eradication was recorded, and the annual direct medical costs of PUD therapy were analyzed. Results: A total of 440 H. pylori‐positive PUD patients received eradication therapy in a 7‐year period. Based on an intention‐to‐treat analysis, the eradication rate was 84.5% (372 of 440). The largest number of patients who received eradication therapy was found in 1995 (n = 115), and from 1995 to 2001 this number decreased yearly by 12.5 (95% confidence interval (CI): 5 to 20). Between 1989 and 1995, the annual medical costs arising of PUD therapy increased by ¥2.25 million (95% CI: 1.19 to 3.31) per year, being highest (¥22.75 million) in 1995. Between 1995 and 2001, the costs decreased by ¥3.88 million (95% CI: 3.16 to 4.59) per year. The cost in 2001 was 5.7% of the cost in 1995. The eradication program was terminated in 2001 because the prevalence of PUD diminished markedly, and the associated medical costs decreased as well. Conclusions: H. pylori eradication could reduce the number of PUD patients and associated medical costs in the workplace setting.     

When Is Rapid On-Site Evaluation Cost-Effective for Fine-Needle Aspiration Biopsy?

Background

Rapid on-site evaluation (ROSE) can improve adequacy rates of fine-needle aspiration biopsy (FNAB) but increases operational costs. The performance of ROSE relative to fixed sampling depends on many factors. It is not clear when ROSE is less costly than sampling with a fixed number of needle passes. The objective of this study was to determine the conditions under which ROSE is less costly than fixed sampling.

Methods

Cost comparison of sampling with and without ROSE using mathematical modeling. Models were based on a societal perspective and used a mechanistic, micro-costing approach. Sampling policies (ROSE, fixed) were compared using the difference in total expected costs per case. Scenarios were based on procedure complexity (palpation-guided or image-guided), adequacy rates (low, high) and sampling protocols (stopping criteria for ROSE and fixed sampling). One-way, probabilistic, and scenario-based sensitivity analysis was performed to determine which variables had the greatest influence on the cost difference.

Results

ROSE is favored relative to fixed sampling under the following conditions: (1) the cytologist is accurate, (2) the total variable cost ($/hr) is low, (3) fixed costs ($/procedure) are high, (4) the setup time is long, (5) the time between needle passes for ROSE is low, (6) when the per-pass adequacy rate is low, and (7) ROSE stops after observing one adequate sample. The model is most sensitive to variation in the fixed cost, the per-pass adequacy rate, and the time per needle pass with ROSE.

Conclusions

Mathematical modeling can be used to predict the difference in cost between sampling with and without ROSE.     

Species‐level biodiversity assessment using marine environmental DNA metabarcoding requires protocol optimization and standardization

DNA extraction from environmental samples (environmental DNA; eDNA) for metabarcoding‐based biodiversity studies is gaining popularity as a noninvasive, time‐efficient, and cost‐effective monitoring tool. The potential benefits are promising for marine conservation, as the marine biome is frequently under‐surveyed due to its inaccessibility and the consequent high costs involved. With increasing numbers of eDNA‐related publications have come a wide array of capture and extraction methods. Without visual species confirmation, inconsistent use of laboratory protocols hinders comparability between studies because the efficiency of target DNA isolation may vary. We determined an optimal protocol (capture and extraction) for marine eDNA research based on total DNA yield measurements by comparing commonly employed methods of seawater filtering and DNA isolation. We compared metabarcoding results of both targeted (small taxonomic group with species‐level assignment) and universal (broad taxonomic group with genus/family‐level assignment) approaches obtained from replicates treated with the optimal and a low‐performance capture and extraction protocol to determine the impact of protocol choice and DNA yield on biodiversity detection. Filtration through cellulose‐nitrate membranes and extraction with Qiagen's DNeasy Blood & Tissue Kit outperformed other combinations of capture and extraction methods, showing a ninefold improvement in DNA yield over the poorest performing methods. Use of optimized protocols resulted in a significant increase in OTU and species richness for targeted metabarcoding assays. However, changing protocols made little difference to the OTU and taxon richness obtained using universal metabarcoding assays. Our results demonstrate an increased risk of false‐negative species detection for targeted eDNA approaches when protocols with poor DNA isolation efficacy are employed. Appropriate optimization is therefore essential for eDNA monitoring to remain a powerful, efficient, and relatively cheap method for biodiversity assessments. For seawater, we advocate filtration through cellulose‐nitrate membranes and extraction with Qiagen's DNeasy Blood & Tissue Kit or phenol‐chloroform‐isoamyl for successful implementation of eDNA multi‐marker metabarcoding surveys.     

A Rapid and effective method for RNA extraction from different tissues of grapevine and other woody plants

Introduction –  RNA quality and integrity are critical for many studies in plant molecular biology. High‐quality RNA extraction from grapevine and other woody plants is problematic due to the presence of polysaccharides, polyphenolics and other compounds that bind or co‐precipitate with the RNA. Objective  – To develop an optimised cetyltrimethylammonium bromide (CTAB)‐based protocol, to reduce the time and cost of extraction without reducing quality and yield of RNA extracted from polysaccharide‐rich tissues of several plants. Methodology  – Several changes were introduced to the original CTAB protocol. All centrifugation steps were carried out at 4°C, the sample weight was decreased and the concentrations of PVP‐40 and LiCl were increased reducing incubation time prior to RNA precipitation. This rapid CTAB protocol was compared with six different RNA extraction methods from three grapevine tissues, namely, in vitro plantlets, and leaves and mature canes from actively growing field vines. Results –  The rapid CTAB method gave high‐quality RNA in only 3 h at low cost with efficiency equal to or higher than that obtained with other time‐consuming and expensive protocols. The procedure was applied to RNA extraction from other grapevine tissues and other woody species including olive, lemon, poplar, chestnut, apple, pear, peach, cherry, apricot, plum and kiwi fruit. RNA of high quality could be isolated from all tissues and from all species. Conclusion –  The study has shown that the improvement of a CTAB‐based protocol allows the rapid isolation of high‐quality RNA from grapevine and many woody species. Copyright © 2008 John Wiley & Sons, Ltd.     

Weekly iron-folic acid supplementation with regular deworming is cost-effective in preventing anaemia in women of reproductive age in Vietnam

Background

To estimate the cost and cost-effectiveness of a project administering de-worming and weekly iron-folic acid supplementation to control anaemia in women of reproductive age in Yen Bai province, Vietnam.

Methods and Findings

Cost effectiveness was evaluated using data on programmatic costs based on two surveys in 2006 and 2009 and impact on anaemia and iron status collected in 2006, 2007, and 2008. Data on initial costs for training and educational materials were obtained from the records of the National Institute of Malariology, Parasitology and Entomology and the Yen Bai Malaria Control Program. Structured questionnaires for health workers at district, commune and village level were used to collect ongoing distribution and monitoring costs, and for participants to collect transport and loss of earnings costs. The cost per woman treated (defined as consuming at least 75% of the recommended intake) was USD0.76 per annum. This estimate includes financial costs (for supplies, training), and costs of health care workers'' time. Prevalence of anaemia fell from 38% at baseline, to 20% after 12 months. Thus, the cost-effectiveness of the project is assessed at USD 4.24 per anaemia case prevented per year. Based on estimated productivity gains for adult women, the benefit:cost ratio is 6.7∶1. Cost of the supplements and anthelminthics was 47% of the total, while costs of training, monitoring, and health workers'' time accounted for 53%.

Conclusion

The study shows that weekly iron-folic acid supplementation and regular de-worming is a low-cost and cost-effective intervention and would be appropriate for population-based introduction in settings with a high prevalence of anaemia and iron deficiency and low malaria infection rates.     

Life cycle cost analysis of the UK housing stock

Purpose

The aim of the paper is to estimate life cycle costs (LCC) of the current housing stock in the UK as part of sustainability assessment of the residential construction sector. This is carried out by first estimating the life cycle costs of individual houses considering detached, semi-detached and terraced homes. These results are then extrapolated to the UK housing stock consisting of seven million each of semi-detached and terraced houses and four million of detached houses. A brief discussion of life cycle environmental impacts is also included to help identify improvement opportunities for both costs and impacts.

Methods

The life cycle costing methodology followed in the study is congruent with the life cycle assessment methodology. The system boundary for the study is from ‘cradle to grave’, including all activities from extraction and manufacture of construction materials to construction and use of the house to its demolition. The functional unit is defined as the construction and occupation of a house in the UK over the lifetime of 50 years.

Results and discussion

The total life cycle costs are estimated at £247,000 for the detached house, £192,000 for the semi-detached and £142,000 for the terraced house. The running costs in the use stage contribute 52 % to the total life cycle costs of which half is from energy use. The construction costs contribute 35 % to the total LCC with the walls and the roof being the most expensive items. The remaining 13 % of the costs are incurred at the end of life of the house which are largely (85 %) due to the cost of labour for demolition. Recovery of end-of-life materials has a limited potential to reduce the overall life cycle costs of a house. The life cycle costs of the whole housing stock are estimated at £67 billion per year or £3,360 billion over the 50-year lifetime.

Conclusions

The existing housing stock in the UK is facing a number of challenges that will need to be addressed in the near future. These include improving energy efficiency and reducing the dependency on fossil fuels to reduce energy demand, fuel poverty and environmental impacts. Furthermore, the disparity between the construction costs and house market prices will need to be addressed to ensure that access to housing and house ownership do not become the privilege of a few.