scholarly journals Marginal cost curves for water footprint reduction in irrigated agriculture: guiding a cost-effective reduction of crop water consumption to a benchmark or permit level

2017 ◽  
Author(s):  
Abebe D. Chukalla ◽  
Maarten S. Krol ◽  
Arjen Y. Hoekstra

Abstract. Reducing the water footprint (WF) of the process of growing irrigated crop is an indispensable element in water management, particularly in water-scarce areas. To achieve this, information on marginal cost curves (MCCs) that rank management packages according to their cost-effectiveness to reduce the WF need to support the decision making. MCCs enable the estimation of the cost associated with a certain WF reduction target, e.g. towards a given WF permit (expressed in m3 per hectare per season) or to a certain WF benchmark (expressed in m3 per tonne of crop). This paper aims to develop MCCs for WF reduction for a range of selected cases. The soil-water-balance and crop-growth model, AquaCrop, is used to estimate the effect on evapotranspiration and crop yield and thus WF of crop production due to different management packages. A management package is defined as specific combination of management practices: irrigation technique (furrow, sprinkler, drip or subsurface drip); irrigation strategy (full or deficit irrigation); and mulching practice (no, organic or synthetic mulching). The annual average cost for each management package is estimated as the annualised capital cost plus the annual costs of maintenance and operations (i.e. costs of water, energy, and labour). Different cases is considered, including: three crops (maize, tomato and potato); four types of environment; three hydrologic years (wet, normal and dry years) and three soil types (loam, silty clay loam and sandy loam). For each crop, alternative WF reduction pathways were developed, after which the most cost-effective pathway was selected to develop the MCC for WF reduction. When aiming at WF reduction one can best improve the irrigation strategy first, next the mulching practice and finally the irrigation technique. Moving from a full to deficit irrigation strategy is found to be a no-regret measure: it reduces the WF by reducing water consumption at negligible yield reduction, while reducing the cost for irrigation water and the associated costs for energy and labour. Next, moving from no to organic mulching has a high cost-effectiveness, reducing the WF significantly at low cost. Finally, changing from sprinkler or furrow to drip or sub-surface drip irrigation reduces the WF but at significant cost.

2017 ◽  
Vol 21 (7) ◽  
pp. 3507-3524 ◽  
Author(s):  
Abebe D. Chukalla ◽  
Maarten S. Krol ◽  
Arjen Y. Hoekstra

Abstract. Reducing the water footprint (WF) of the process of growing irrigated crops is an indispensable element in water management, particularly in water-scarce areas. To achieve this, information on marginal cost curves (MCCs) that rank management packages according to their cost-effectiveness to reduce the WF need to support the decision making. MCCs enable the estimation of the cost associated with a certain WF reduction target, e.g. towards a given WF permit (expressed in m3  ha−1 per season) or to a certain WF benchmark (expressed in m3  t−1 of crop). This paper aims to develop MCCs for WF reduction for a range of selected cases. AquaCrop, a soil-water-balance and crop-growth model, is used to estimate the effect of different management packages on evapotranspiration and crop yield and thus the WF of crop production. A management package is defined as a specific combination of management practices: irrigation technique (furrow, sprinkler, drip or subsurface drip); irrigation strategy (full or deficit irrigation); and mulching practice (no, organic or synthetic mulching). The annual average cost for each management package is estimated as the annualized capital cost plus the annual costs of maintenance and operations (i.e. costs of water, energy and labour). Different cases are considered, including three crops (maize, tomato and potato); four types of environment (humid in UK, sub-humid in Italy, semi-arid in Spain and arid in Israel); three hydrologic years (wet, normal and dry years) and three soil types (loam, silty clay loam and sandy loam). For each crop, alternative WF reduction pathways were developed, after which the most cost-effective pathway was selected to develop the MCC for WF reduction. When aiming at WF reduction one can best improve the irrigation strategy first, next the mulching practice and finally the irrigation technique. Moving from a full to deficit irrigation strategy is found to be a no-regret measure: it reduces the WF by reducing water consumption at negligible yield reduction while reducing the cost for irrigation water and the associated costs for energy and labour. Next, moving from no to organic mulching has a high cost-effectiveness, reducing the WF significantly at low cost. Finally, changing from sprinkler or furrow to drip or subsurface drip irrigation reduces the WF, but at a significant cost.


Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 707
Author(s):  
Afifah Machlaurin ◽  
Franklin Christiaan Karel Dolk ◽  
Didik Setiawan ◽  
Tjipke Sytse van der Werf ◽  
Maarten J. Postma

Bacillus Calmette–Guerin (BCG), the only available vaccine for tuberculosis (TB), has been applied for decades. The Indonesian government recently introduced a national TB disease control programme that includes several action plans, notably enhanced vaccination coverage, which can be strengthened through underpinning its favourable cost-effectiveness. We designed a Markov model to assess the cost-effectiveness of Indonesia’s current BCG vaccination programme. Incremental cost-effectiveness ratios (ICERs) were evaluated from the perspectives of both society and healthcare. The robustness of the analysis was confirmed through univariate and probabilistic sensitivity analysis (PSA). Using epidemiological data compiled for Indonesia, BCG vaccination at a price US$14 was estimated to be a cost-effective strategy in controlling TB disease. From societal and healthcare perspectives, ICERs were US$104 and US$112 per quality-adjusted life years (QALYs), respectively. The results were robust for variations of most variables in the univariate analysis. Notably, the vaccine’s effectiveness regarding disease protection, vaccination costs, and case detection rates were key drivers for cost-effectiveness. The PSA results indicated that vaccination was cost-effective even at US$175 threshold in 95% of cases, approximating the monthly GDP per capita. Our findings suggest that this strategy was highly cost-effective and merits prioritization and extension within the national TB programme. Our results may be relevant for other high endemic low- and middle-income countries.


1999 ◽  
Vol 6 (4) ◽  
pp. 332-335 ◽  
Author(s):  
Jennifer A Crocket ◽  
Eric YL Wong ◽  
Dale C Lien ◽  
Khanh Gia Nguyen ◽  
Michelle R Chaput ◽  
...  

OBJECTIVE: To evaluate the yield and cost effectiveness of transbronchial needle aspiration (TBNA) in the assessment of mediastinal and/or hilar lymphadenopathy.DESIGN: Retrospective study.SETTING: A university hospital.POPULATION STUDIED: Ninety-six patients referred for bronchoscopy with computed tomographic evidence of significant mediastinal or hilar adenopathy.RESULTS: Ninety-nine patient records were reviewed. Three patients had two separate bronchoscopy procedures. TBNA was positive in 42 patients (44%) and negative in 54 patients. Of the 42 patients with a positive aspirate, 40 had malignant cytology and two had cells consistent with benign disease. The positive TBNA result altered management in 22 of 40 patients with malignant disease and one of two patients with benign disease, thereby avoiding further diagnostic procedures. The cost of these subsequent procedures was estimated at $27,335. No complications related to TBNA were documented.CONCLUSIONS: TBNA is a high-yield, safe and cost effective procedure for the diagnosis and staging of bronchogenic cancer.


2020 ◽  
Vol 33 (4/5) ◽  
pp. 323-331
Author(s):  
Mohsen pakdaman ◽  
Raheleh akbari ◽  
Hamid reza Dehghan ◽  
Asra Asgharzadeh ◽  
Mahdieh Namayandeh

PurposeFor years, traditional techniques have been used for diabetes treatment. There are two major types of insulin: insulin analogs and regular insulin. Insulin analogs are similar to regular insulin and lead to changes in pharmacokinetic and pharmacodynamic properties. The purpose of the present research was to determine the cost-effectiveness of insulin analogs versus regular insulin for diabetes control in Yazd Diabetes Center in 2017.Design/methodology/approachIn this descriptive–analytical research, the cost-effectiveness index was used to compare insulin analogs and regular insulin (pen/vial) for treatment of diabetes. Data were analyzed in the TreeAge Software and a decision tree was constructed. A 10% discount rate was used for ICER sensitivity analysis. Cost-effectiveness was examined from a provider's perspective.FindingsQALY was calculated to be 0.2 for diabetic patients using insulin analogs and 0.05 for those using regular insulin. The average cost was $3.228 for analog users and $1.826 for regular insulin users. An ICER of $0.093506/QALY was obtained. The present findings suggest that insulin analogs are more cost-effective than regular insulin.Originality/valueThis study was conducted using a cost-effectiveness analysis to evaluate insulin analogs versus regular insulin in controlling diabetes. The results of study are helpful to the government to allocate more resources to apply the cost-effective method of the treatment and to protect patients with diabetes from the high cost of treatment.


1996 ◽  
Vol 3 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Afaf Girgis ◽  
Philip Clarke ◽  
Robert C Burton ◽  
Rob W Sanson—Fisher

Background and design— Australia has the highest rates of skin cancer in the world, and the incidence is estimated to be doubling every 10 years. Despite advances in the early detection and treatment of melanoma about 800 people still die nationally of the disease each year. A possible strategy for further reducing the mortality from melanoma is an organised programme of population screening for unsuspected lesions in asymptomatic people. Arguments against introducing melanoma screening have been based on cost and the lack of reliable data on the efficacy of any screening tests. To date, however, there has been no systematic economic assessment of the cost effectiveness of melanoma screening. The purpose of this research was to determine whether screening may be potentially cost effective and, therefore, warrants further investigation. A computer was used to simulate the effects of a hypothetical melanoma screening programme that was in operation for 20 years, using cohorts of Australians aged 50 at the start of the programme. Based on this simulation, cost—effectiveness estimates of melanoma screening were calculated. Results— Under the standard assumptions used in the model, and setting the sensitivity of the screening test (visual inspection of the skin) at 60%, cost effectiveness ranged from Aust$6853 per life year saved for men if screening was undertaken five yearly to $12137 if screening was two yearly. For women, it ranged from $11 102 for five yearly screening to $20 877 for two yearly screening. Conclusion— The analysis suggests that a melanoma screening programme could be cost effective, particularly if five yearly screening is implemented by family practitioners for men over the age of 50.


2021 ◽  
pp. 019459982110268
Author(s):  
Joseph R. Acevedo ◽  
Ashley C. Hsu ◽  
Jeffrey C. Yu ◽  
Dale H. Rice ◽  
Daniel I. Kwon ◽  
...  

Objective To compare the cost-effectiveness of sialendoscopy with gland excision for the management of submandibular gland sialolithiasis. Study Design Cost-effectiveness analysis. Setting Outpatient surgery centers. Methods A Markov decision model compared the cost-effectiveness of sialendoscopy versus gland excision for managing submandibular gland sialolithiasis. Surgical outcome probabilities were found in the primary literature. The quality of life of patients was represented by health utilities, and costs were estimated from a third-party payer’s perspective. The effectiveness of each intervention was measured in quality-adjusted life-years (QALYs). The incremental costs and effectiveness of each intervention were compared, and a willingness-to-pay ratio of $150,000 per QALY was considered cost-effective. One-way, multivariate, and probabilistic sensitivity analyses were performed to challenge model conclusions. Results Over 10 years, sialendoscopy yielded 9.00 QALYs at an average cost of $8306, while gland excision produced 8.94 QALYs at an average cost of $6103. The ICER for sialendoscopy was $36,717 per QALY gained, making sialendoscopy cost-effective by our best estimates. The model was sensitive to the probability of success and the cost of sialendoscopy. Sialendoscopy must meet a probability-of-success threshold of 0.61 (61%) and cost ≤$11,996 to remain cost-effective. A Monte Carlo simulation revealed sialendoscopy to be cost-effective 60% of the time. Conclusion Sialendoscopy appears to be a cost-effective management strategy for sialolithiasis of the submandibular gland when certain thresholds are maintained. Further studies elucidating the clinical factors that determine successful sialendoscopy may be aided by these thresholds as well as future comparisons of novel technology.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Obinna Ikechukwu Ekwunife ◽  
Chinelo Janefrances Ofomata ◽  
Charles Ebuka Okafor ◽  
Maureen Ugonwa Anetoh ◽  
Stephen Okorafor Kalu ◽  
...  

Abstract Background In sub-Saharan Africa, there is increasing mortality and morbidity of adolescents due to poor linkage, retention in HIV care and adherence to antiretroviral therapy (ART). This is a result of limited adolescent-centred service delivery interventions. This cost-effectiveness and feasibility study were piggybacked on a cluster-randomized trial that assessed the impact of an adolescent-centred service delivery intervention. The service delivery intervention examined the impact of an incentive scheme consisting of conditional economic incentives and motivational interviewing on the health outcomes of adolescents living with HIV in Nigeria. Method A cost-effectiveness analysis from the healthcare provider’s perspective was performed to assess the cost per additional patient achieving undetected viral load through the proposed intervention. The cost-effectiveness of the incentive scheme over routine care was estimated using the incremental cost-effectiveness ratio (ICER), expressed as cost/patient who achieved an undetectable viral load. We performed a univariate sensitivity analysis to examine the effect of key parameters on the ICER. An in-depth interview was conducted on the healthcare personnel in the intervention arm to explore the feasibility of implementing the service delivery intervention in HIV treatment hospitals in Nigeria. Result The ICER of the Incentive Scheme intervention compared to routine care was US$1419 per additional patient with undetectable viral load. Going by the cost-effectiveness threshold of US$1137 per quality-adjusted life-years suggested by Woods et al., 2016, the intervention was not cost-effective. The sensitivity test showed that the intervention will be cost-effective if the frequency of CD4 count and viral load tests are reduced from quarterly to triannually. Healthcare professionals reported that patients’ acceptance of the intervention was very high. Conclusion The conditional economic incentives and motivational interviewing was not cost-effective, but can become cost-effective if the frequency of HIV quality of life indicator tests are performed 1–3 times per annum. Patients’ acceptance of the intervention was very high. However, healthcare professionals believed that sustaining the intervention may be difficult unless factors such as government commitment and healthcare provider diligence are duly addressed. Trial registration This trial is registered in the WHO International Clinical Trials Registry through the WHO International Registry Network (PACTR201806003040425).


Mathematics ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 566
Author(s):  
Julio Emilio Marco-Franco ◽  
Pedro Pita-Barros ◽  
Silvia González-de-Julián ◽  
Iryna Sabat ◽  
David Vivas-Consuelo

When exceptional situations, such as the COVID-19 pandemic, arise and reliable data is not available at decision-making times, estimation using mathematical models can provide a reasonable reckoning for health planning. We present a simplified model (static but with two-time references) for estimating the cost-effectiveness of the COVID-19 vaccine. A simplified model provides a quick assessment of the upper bound of cost-effectiveness, as we illustrate with data from Spain, and allows for easy comparisons between countries. It may also provide useful comparisons among different vaccines at the marketplace, from the perspective of the buyer. From the analysis of this information, key epidemiological figures, and costs of the disease for Spain have been estimated, based on mortality. The fatality rate is robust data that can alternatively be obtained from death registers, funeral homes, cemeteries, and crematoria. Our model estimates the incremental cost-effectiveness ratio (ICER) to be 5132 € (4926–5276) as of 17 February 2021, based on the following assumptions/inputs: An estimated cost of 30 euros per dose (plus transport, storing, and administration), two doses per person, efficacy of 70% and coverage of 70% of the population. Even considering the possibility of some bias, this simplified model provides confirmation that vaccination against COVID-19 is highly cost-effective.


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