Spatial preferences for invasion management: a choice experiment on controlling Ludwigia grandiflora in a French regional park

Biological Invasions - If individuals have spatially differentiated preferences for sites or areas impacted by an invasive alien species, effective management must take this heterogeneity into...     

Reasons for cannabis use during pregnancy and lactation: a qualitative study

Background:Cannabis use among pregnant and lactating people is increasing, despite clinical evidence showing that cannabis use may be associated with low birth weight and childhood developmental deficits. Our objective was to understand why pregnant and lactating people use cannabis and how these motivations change across perinatal stages.Methods:Using qualitative, constructivist grounded theory methodology, we conducted telephone and virtual interviews with 52 individuals from across Canada. We selected participants using maximum variation and theoretical sampling. They were eligible if they had been pregnant or lactating within the past year and had decided to continue, cease or decrease their cannabis use during the perinatal period.Results:We identified 3 categories of reasons that people use cannabis during pregnancy and lactation: sensation-seeking for fun and enjoyment; symptom management of chronic conditions and conditions related to pregnancy; and coping with the unpleasant, but nonpathologized, experiences of life. Before pregnancy, participants endorsed reasons for using cannabis in these 3 categories in similar proportions, with many offering multiple reasons for use. During pregnancy, reasons for use shifted primarily to symptom management. During lactation, reasons returned to resemble those expressed before pregnancy.Interpretation:In this study, we showed that pregnant and lactating people use cannabis for many reasons, particularly for symptom management. Reasons for cannabis use changed across reproductive stages. The dynamic nature of the reasons for use across stages speaks to participant perception of benefits and risks, and perhaps a desire to cast cannabis use during pregnancy as therapeutic because of perceived stigma.

Cannabis use by pregnant and lactating people is increasing, though it is difficult to establish the prevalence of cannabis use in pregnancy. Reported prevalence varies from 2% to 36%, depending on the methodology used to detect use, the population studied and the definition of use.^1–12 Pregnant people have reported using cannabis to manage pregnancy-related conditions (e.g., nausea, weight gain, sleep difficulty)^13–19 and pre-existing conditions (e.g., mental health, insomnia, chronic pain),^13,14,18 as well as to improve mood, mental, physical and spiritual well-being,^16,18 provide pleasure and manage stress.^13–16 Recent systematic reviews have not found empirical data on reasons for cannabis use during lactation.^20,21Evidence is still emerging about clinical outcomes related to cannabis use during pregnancy and lactation, and well-controlled studies are lacking.^22–24 The available evidence is limited by reliance on self-reported data about dose, composition and timing of exposure, the changing nature of tetrahydrocannabinol levels in cannabis over time, and a lack of studies that control for known confounders such as polysubstance and tobacco use.^25–31 The available evidence does suggest that cannabis use during pregnancy may be associated with complications such as low birth weight, childhood neurodevelopmental outcomes and preterm birth.^{22–24,32,33} Very few studies have analyzed the outcomes associated with cannabis exposure through breastmilk, with 1 study suggesting decreased infant motor development and another showing no effects on developmental outcomes.^34–36 Given the potential harms identified, and in the absence of high-quality evidence available to guide practice, most clinical guidelines recommend abstinence from cannabis during pregnancy and lactation.^37–39People who perceive benefits from cannabis may wish to or may be motivated to continue using it through pregnancy and lactation, however. Counselling that explores the reasons patients are considering cannabis use and suggests related alternatives or harm reduction strategies has been identified as a helpful strategy to minimize potential harm.^13,40,41,42 Such an approach requires that clinicians understand the motivations to use cannabis before pregnancy, during pregnancy and during lactation. We sought to explore why people use cannabis during pregnancy and lactation.     

Lemming winter habitat choice: a snow-fencing experiment

The insulative value of early and deep winter snow is thought to enhance winter reproduction and survival by arctic lemmings (Lemmus and Dicrostonyx spp). This leads to the general hypothesis that landscapes with persistently low lemming population densities, or low amplitude population fluctuations, have a low proportion of the land base with deep snow. We experimentally tested a component of this hypothesis, that snow depth influences habitat choice, at three Canadian Arctic sites: Bylot Island, Nunavut; Herschel Island, Yukon; Komakuk Beach, Yukon. We used snow fencing to enhance snow depth on 9-ha tundra habitats, and measured the intensity of winter use of these and control areas by counting rodent winter nests in spring. At all three sites, the density of winter nests increased in treated areas compared to control areas after the treatment, and remained higher on treated areas during the treatment. The treatment was relaxed at one site, and winter nest density returned to pre-treatment levels. The rodents’ proportional use of treated areas compared to adjacent control areas increased and remained higher during the treatment. At two of three sites, lemmings and voles showed significant attraction to the areas of deepest snow accumulation closest to the fences. The strength of the treatment effect appeared to depend on how quickly the ground level temperature regime became stable in autumn, coincident with snow depths near the hiemal threshold. Our results provide strong support for the hypothesis that snow depth is a primary determinant of winter habitat choice by tundra lemmings and voles.     

The choice of a statistic for testing hypotheses regarding seasonality

This paper discusses statistical methods for testing hypotheses of seasonality in births across one year, using monthly frequencies. It argues that the Freedman test, a variant of the Kolmogorov-Smirnov one-sample test, and the Edwards test and its modifications are most appropriate for this purpose. These tests take into account the order of the monthly frequencies and have a higher power than the ordinary chi-square goodness-of-fit test, regarding seasonality. The paper addresses some points mentioned in earlier papers by McCullough, and O'Brien and Holbert.     

The safety of psychotropic drug use during pregnancy: a review

A substantial number of women of childbearing age are prescribed psychotropic drugs, and because nearly 50% of pregnancies are unplanned, many women are still taking them upon becoming pregnant. This article reviews the various classes of psychotropic drugs that are commonly used to treat psychiatric disorders--antidepressants, benzodiazepines, antipsychotics, antiepileptics, lithium and monoamine oxidase (MAO) inhibitors--in terms of their safety during pregnancy. Evidence-based information from epidemiologic studies indicates that most psychotropic drugs are relatively safe for use during pregnancy. There is also an increasingly large body of evidence-based information in the literature indicating that it may be more harmful to both the mother and her baby if she is not treated appropriately when suffering from a severe psychiatric disorder. Therefore, it is important for women with psychiatric disorders and their healthcare providers to have access to evidenced-based information about the safety of these drugs when taken during pregnancy to ensure that women make an informed decision as to whether they should continue with the pharmacotherapy they have been using to treat their condition.     

Fitness consequences of host plant choice: a field experiment

Determining the relative contributions of different ecological factors for herbivore fitness is one key to understanding the ecology and evolution of host plant choice by herbivores. Natural enemies are increasingly being recognized as an important factor: host plants of inferior quality for development may still be used by herbivores if they provide enemy‐free space (EFS). Here we used the tobacco hornworm, Manduca sexta, to experimentally disentangle the effects of natural enemies from the potentially confounding factors of host plant quality, competition and microhabitat. We explored the consequences for both individual components of fitness and total fitness of M. sexta feeding on a typical high quality host plant, tobacco Nicotiana tabacum and a novel, low quality host plant, devil's claw Proboscidea louisianica in an experimental field environment in the presence of a parasitoid natural enemy, Cotesia congregata. Although early larval survival, development and growth rates, final body size and fecundity were all reduced for M. sexta feeding on devil's claw, a high rate of parasitism on tobacco and an absence of parasitism on devil's claw contributed to similar total fitness (net reproductive rate, R₀) across the two host plant species. Our results suggest M. sexta has adopted a novel host plant (devil's claw) outside its typical host range because this host plant provides enemy free space. In addition, oviposition behavior of adult female M. sexta appears to be well suited to exploiting the enemy‐free space on devil's claw; oviposition by M. sexta on devil's claw appears to correspond with seasonal variation in parasitoid abundance.     

Evaluating health workers' potential resistance to new interventions: a role for discrete choice experiments

Background

The currently recommended approach for preventing malaria in pregnancy (MiP), intermittent preventive treatment with sulphadoxine-pyrimethamine (SP-IPT), has been questioned due to the spread of resistance to SP. Whilst trials are underway to test the efficacy of future alternative approaches, it is important to start exploring the feasibility of their implementation.

Methods and Findings

This study uses a discrete choice experiment (DCE) method to assess the potential resistance of health workers to changing strategies for control of MiP. In Ashanti region in Ghana, 133 antenatal clinic health workers were presented with 16 choice sets of two alternative policy options, each consisting of a bundle of six attributes representing certain clinical guidelines for controlling MiP (type of approach and drug used), possible associated maternal and neo-natal outcomes, workload and financial incentives. The data were analysed using a random effects logit model. Overall, staff showed a preference for a curative approach with pregnant women tested for malaria parasites and treated only if positive, compared to a preventive approach (OR 1.6; p = 0.001). Increasing the incidence of low birth weight or severe anaemia by 1% would reduce the odds of preferring an approach by 18% and 10% respectively. Midwives were more resistant to potential changes to current guidelines than lower-level cadres.

Conclusions

In Ashanti Region, resistance to change by antenatal clinic workers from a policy of SP-IPT to IST would generally be low, and it would disappear amongst midwives if health outcomes for the mother and baby were improved by the new strategy. DCEs are a promising approach to identifying factors that will increase the likelihood of effective implementation of new interventions immediately after their efficacy has been proven.     

Importance of attributes and willingness to pay for oral anticoagulant therapy in patients with atrial fibrillation in China: A discrete choice experiment

BackgroundAdherence to oral anticoagulant therapy in patients with atrial fibrillation (AF) in China is low. Patient preference, one of the main reasons for discontinuation of oral anticoagulant therapy, is an unfamiliar concept in China.Methods and findingsA discrete choice experiment (DCE) was conducted to quantify patient preference on 7 attributes of oral anticoagulant therapy: antidote (yes/no), food–drug interaction (yes/no), frequency of blood monitoring (no need, every 6/3/1 month[s]), risk of nonfatal major bleeding (0.7/3.1/5.5/7.8[%]), risk of nonfatal stroke (ischemic/hemorrhagic) or systemic embolism (0.6/3.2/5.8/8.4[%]), risk of nonfatal acute myocardial infarction (AMI) (0.2/1.0/1.8/2.5[%]), and monthly out-of-pocket cost (0/120/240/360 RMB) (0 to 56 USD). A total of 16 scenarios were generated by using D-Efficient design and were randomly divided into 2 blocks. Eligible patients were recruited and interviewed from outpatient and inpatient settings of 2 public hospitals in Beijing and Shenzhen, respectively. Patients were presented with 8 scenarios and asked to select 1 of 3 options: 2 unlabeled hypothetical treatments and 1 opt-out option. Mixed logit regression model was used for estimating patients’ preferences of attributes of oral anticoagulants and willingness to pay (WTP) with adjustments for age, sex, education level, income level, city, self-evaluated health score, histories of cardiovascular disease/other vascular disease/any stroke/any bleeding, and use of anticoagulant/antiplatelet therapy. A total of 506 patients were recruited between May 2018 and December 2019 (mean age 70.3 years, 42.1% women). Patients were mainly concerned about the risks of AMI (β: −1.03; 95% CI: −1.31, −0.75; p < 0.001), stroke or systemic embolism (β: −0.81; 95% CI: −0.90, −0.73; p < 0.001), and major bleeding (β: −0.69; 95% CI: −0.78, −0.60; p < 0.001) and were willing to pay more, from up to 798 RMB to 536 RMB (124 to 83 USD) monthly. The least concerning attribute was frequency of blood monitoring (β: −0.31; 95% CI: −0.39, −0.24; p < 0.001). Patients had more concerns about food–drug interactions even exceeding preferences on the 3 risks, if they had a history of stroke or bleeding (β: −2.47; 95% CI: −3.92, −1.02; p < 0.001), recruited from Beijing (β: −1.82; 95% CI: −2.56, −1.07; p < 0.001), or men (β: −0.96; 95% CI: −1.36, −0.56; p < 0.001). Patients with lower educational attainment or lower income weighted all attributes lower, and their WTP for incremental efficacy and safety was minimal. Since the patients were recruited from 2 major hospitals from developed cities in China, further studies with better representative samples would be needed.ConclusionsPatients with AF in China were mainly concerned about the safety and effectiveness of oral anticoagulant therapy. The preference weighting on food–drug interaction varied widely. Patients with lower educational attainment or income levels and less experience of bleeding or stroke had more reservations about paying for oral anticoagulant therapies with superior efficacy, safety, and convenience of use.

In a discrete choice experiment, Jiaxi Zhao and colleagues investigate the importance of attributes of oral anticoagulant therapy and willingness-to-pay in patients with atrial fibrillation in China.     

Societal preferences for the return of incidental findings from clinical genomic sequencing: a discrete-choice experiment

Background:An important challenge with the application of next-generation sequencing technology is the possibility of uncovering incidental genomic findings. A paucity of evidence on personal utility for incidental findings has hindered clinical guidelines. Our objective was to estimate personal utility for complex information derived from incidental genomic findings.Methods:We used a discrete-choice experiment to evaluate participants’ personal utility for the following attributes: disease penetrance, disease treatability, disease severity, carrier status and cost. Study participants were drawn from the Canadian public. We analyzed the data with a mixed logit model.Results:In total, 1200 participants completed our questionnaire (available in English and French). Participants valued receiving information about high-penetrance disorders but expressed disutility for receiving information on low-penetrance disorders. The average willingness to pay was $445 (95% confidence interval [CI] $322–$567) to receive incidental findings in a scenario where clinicians returned information about high-penetrance, medically treatable disorders, but only 66% of participants (95% CI 63%–71%) indicated that they would choose to receive information in that scenario. On average, participants placed an important value ($725, 95% CI $600–$850) on having a choice about what type of findings they would receive, including receipt of information about high-penetrance, treatable disorders or receipt of information about high-penetrance disorders with or without available treatment. The predicted uptake of that scenario was 76% (95% CI 72%–79%).Interpretation:Most participants valued receiving incidental findings, but personal utility depended on the type of finding, and not all participants wanted to receive incidental results, regardless of the potential health implications. These results indicate that to maximize benefit, participant-level preferences should inform the decision about whether to return incidental findings.Clinical genomic sequencing technologies are on the verge of allowing individualized care at reasonable cost.¹ Patients and their families will soon receive information from clinical sequencing that has implications for clinical care, including information on consequences related to disease prognosis, treatment response or hereditary risk for disease.² Clinical sequencing can also generate incidental findings, which are clinically relevant genetic variants for disorders unrelated to the reason for ordering the genetic testing. The decision of whether to provide information about incidental findings is complex because such results will have varying clinical validity (whether the genetic variant causes the disorder) and utility (whether effective medical treatment is available for the disorder).^3,4 For example, although effective medical treatment may be available for some validated incidental findings, other incidental findings may not be validated as causing the disorder, and still others will be validated but not associated with effective treatment options.To address in part the challenges surrounding the return of incidental findings, the American College of Medical Genetics and Genomics published recommendations for reporting incidental findings from clinical sequencing.⁵ The statement lists a minimum of 56 genes that laboratories should examine, with results reported to patients through the managing physician. This list includes genes with high-penetrance mutations (i.e., a high proportion of individuals with the mutation will exhibit clinical symptoms) validated to be associated with disorders for which medical interventions are available.The original version of this statement did not “favour offering the patient a preference” for which results would be returned. The reasoning was that clinicians have a duty to prevent potential harm by telling patients about incidental findings. The working group that developed the recommendations further stated that it is impractical to provide the level of genetic counselling required for informed preference on all potential disorders.⁵ As such, the working group recommended that clinicians discuss with patients the possibility of receiving incidental findings from the list. It was argued that patient autonomy is preserved because patients can decline clinical sequencing if they prefer to not receive information about incidental findings.⁵ However, this rationale has been subject to debate because of its “all-or-none” nature, whereby patients must agree to receive information about incidental findings or clinical sequencing is not provided.^6–9 In April 2014, in response to the ongoing debate, the statement was amended to include an “opt-out” option for patients who do not want to receive information about incidental findings.¹⁰Notwithstanding the ethical debate, there is a lack of quantitative, preference-based economic evidence for the return of incidental genomic findings.⁸ It has been argued⁸ that this gap in evidence hindered development of the working group’s recommendation statement. More generally, evidence on preferences for the return of incidental findings is crucial for health policy, for health systems planning and for informing future lists that may include “many more genes.”⁸ We aimed to generate evidence on the personal utility that study participants from the Canadian public ascribe to the return of incidental genomic findings in the clinical setting. We chose participants from the general public because the public is the largest stakeholder in Canada’s publicly funded health care system.     

Public preferences for health care: prioritisation in the United Kingdom

The Government in the UK is encouraging consumerism within health care and is requiring Health Authorities to consult with the public on prioritisation of resources. Public consultation within the National Health Service (NHS) has had limited success in the past. Many of the techniques used are flawed. Despite the limited scope of the public surveys conducted so far, a number of themes have emerged: a willingness to pay for experimental, 'high-tech' life-saving treatments rather than more cost-effective treatments which will improve quality of life, which are more likely to maximise utility from the scarce resources available; preference for treating the young rather than the old; preference for treating patients with dependents (e.g. spouse, children) rather than those who have none; a willingness to discriminate against those patients who were partially responsible for their illness due to choice of 'unhealthy' lifestyle (e.g. smoking cigarettes, drinking excess alcohol). These public preferences raise ethical problems. For example, is it just to spend more on heroic treatments which are likely to fail? Is there a right to health care irrespective of whether you have had 'a fair innings' or whether a patient is in part responsible for their illness due to an unhealthy lifestyle? If there are ethical concerns about these preferences, should health authorities consult with the public at all? Is human life and suffering incommensurable, and hence is it impossible to prioritise anyway? Some of the ethical consequences of using empirical data on public preferences are discussed.     

Application of discrete choice experiments to enhance stakeholder engagement as a strategy for advancing implementation: a systematic review

Background

One of the key strategies to successful implementation of effective health-related interventions is targeting improvements in stakeholder engagement. The discrete choice experiment (DCE) is a stated preference technique for eliciting individual preferences over hypothetical alternative scenarios that is increasingly being used in health-related applications. DCEs are a dynamic approach to systematically measure health preferences which can be applied in enhancing stakeholder engagement. However, a knowledge gap exists in characterizing the extent to which DCEs are used in implementation science.

Methods

We conducted a systematic literature search (up to December 2016) of the English literature to identify and describe the use of DCEs in engaging stakeholders as an implementation strategy. We searched the following electronic databases: MEDLINE, Econlit, PsychINFO, and the CINAHL using mesh terms. Studies were categorized according to application type, stakeholder(s), healthcare setting, and implementation outcome.

Results

Seventy-five publications were selected for analysis in this systematic review. Studies were categorized by application type: (1) characterizing demand for therapies and treatment technologies (n?=?32), (2) comparing implementation strategies (n?=?22), (3) incentivizing workforce participation (n?=?11), and (4) prioritizing interventions (n?=?10). Stakeholders included providers (n?=?27), patients (n?=?25), caregivers (n?=?5), and administrators (n?=?2). The remaining studies (n?=?16) engaged multiple stakeholders (i.e., combination of patients, caregivers, providers, and/or administrators). The following implementation outcomes were discussed: acceptability (n?=?75), appropriateness (n?=?34), adoption (n?=?19), feasibility (n?=?16), and fidelity (n?=?3).

Conclusions

The number of DCE studies engaging stakeholders as an implementation strategy has been increasing over the past decade. As DCEs are more widely used as a healthcare assessment tool, there is a wide range of applications for them in stakeholder engagement. The DCE approach could serve as a tool for engaging stakeholders in implementation science.

     

Identification of smallholder farmers and pastoralists' preferences for sheep breeding traits: choice model approach

Identification of breeding objective traits pertinent to specific production environments with the involvement of target beneficiaries is crucial to the success of a breed improvement program. A choice experiment was conducted in four locations representing different production systems and agro-ecologies that are habitat to four indigenous sheep breeds (Afar, Bonga, Horro and Menz) of Ethiopia with the objective of identifying farmers'/pastoralists' preferences for sheep breeding traits. Following a synthesis of secondary information and diagnostic surveys, two communities per location consisting of 60 households each having at least four breeding ewes were identified. Producers' priority attributes used in the choice sets were identified through in-depth production system studies conducted from December 2007 to March 2008. On the basis of prior information, four to seven attributes were used to design choice sets with different profiles in order to capture results that mimic real life of the different communities. The attributes and levels chosen for the sheep profile were as follows: body size (large/small), coat color (brown/white/black), tail type (good/bad) for both rams and ewes; horn (polled/horned) and libido (active/poor) for rams; and lambing interval (three lambings in 2 years/two lambings in 2 years time), mothering ability (good mother/bad mother), twinning rate (twin bearer/single bearer) and milk yield (two cups per milking/one cup per milking) for ewes. A fractional factorial design was implemented to construct the alternatives included in the choice sets. The design resulted in a randomized selection of 48 sheep profiles (24 sets) for both sexes, which were grouped into four blocks with six choice sets each. An individual respondent was presented with one of the four blocks to make his/her choices. Results indicate that producers' trait preferences were heterogeneous except for body size in rams and mothering ability in ewes where nearly homogeneous preferences were investigated. In the pastoral production system, attention was given to coat color of both breeding rams and ewes, favoring brown and white colors over black. Ram libido influenced producers' decisions in Bonga, Horro and Menz areas. The influence of milk yield and twinning on respondents' decision making was high in Afar and Horro, respectively. Breeders in all areas attempt to combine production and reproduction traits as well as they can in order to maximize benefits from their sheep. The elicited measurable objective traits were used to design alternative community-based sheep breeding plans for the four indigenous sheep breeds in their production environments that have been implemented since.     

Density-dependence across dispersal stages in a hermaphrodite land snail: insights from discrete choice models

Dispersal movements, i.e. movements leading to gene flow, are key behaviours with important, but only partially understood, consequences for the dynamics and evolution of populations. In particular, density-dependent dispersal has been widely described, yet how it is determined by the interaction with individual traits, and whether density effects differ between the three steps of dispersal (departure, transience, and settlement), remains largely unknown. Using a semi-natural landscape, we studied dispersal choices of Cornu aspersum land snails, a species in which negative effects of crowding are well documented, and analysed them using dispersal discrete choice models, a new method allowing the analysis of dispersal decisions by explicitly considering the characteristics of all available alternatives and their interaction with individual traits. Subadults were more dispersive than adults, confirming existing results. In addition, departure and settlement were both density dependent: snails avoided crowded patches at both ends of the dispersal process, and subadults were more reluctant to settle into crowded patches than adults. Moreover, we found support for carry-over effects of release density on subsequent settlement decisions: snails from crowded contexts were more sensitive to density in their subsequent immigration choices. The fact that settlement decisions were informed indicates that costs of prospecting are not as important as previously thought in snails, and/or that snails use alternative ways to collect information, such as indirect social information (e.g. trail following). The observed density-dependent dispersal dynamics may play an important role in the ability of C. aspersum to successfully colonise frequently human-disturbed habitats around the world.