Understanding uncertainty

The rat frontal orienting field dynamically encodes value for economic decisions under risk

Frontal and parietal cortex are implicated in economic decision-making, but their causal roles are untested. Here we silenced the frontal orienting field (FOF) and posterior parietal cortex (PPC) while rats chose between a cued lottery and a small stable surebet. PPC inactivations produced minimal short-lived effects. FOF inactivations reliably reduced lottery choices. A mixed-agent model of choice indicated that silencing the FOF caused a change in the curvature of the rats' utility function (U = Vρ). Consistent with this finding, single-neuron and population analyses of neural activity confirmed that the FOF encodes the lottery value on each trial. A dynamical model, which accounts for electrophysiological and silencing results, suggests that the FOF represents the current lottery value to compare against the remembered surebet value. These results demonstrate that the FOF is a critical node in the neural circuit for the dynamic representation of action values for choice under risk.

Fear and anxiety in the face of COVID-19: Negative dispositions towards risk and uncertainty as vulnerability factors

In the face of the COVID-19 pandemic it is important to identify factors that make people particularly vulnerable of developing mental-health issues in order to provide case-specific treatments. In this article, we examine the roles of two psychological constructs - originally put forth in the behavioral decision sciences - in predicting interindividual differences in fear responses: general risk aversion (GRA) and intolerance of uncertainty (IU). We first provide a review of these constructs and illustrate why they may play important roles in shaping anxiety-related disorders. Thereafter we present an empirical study that collected survey data from 550 U.S. residents, comprising self-assessments of dispositions towards risk and uncertainty, anxiety- and depression levels, as well as demographic variables - to thus test the extent to which these psychological constructs are predictive of strong fear responses related to COVID-19 (i.e., mortal fear, racing heart). The results from Bayesian multi-model inference analyses showed that GRA and IU were more powerful predictors of fear responses than demographic variables. Moreover, the predictive power of these constructs was independent of general anxiety- and depression levels. Subsequent mediation analyses showed that the effects of GRA and IU were both direct and indirect via anxiety. We conclude by discussing possible treatment options, but also highlight that future research needs to further examine causal pathways and conceptual overlaps.

The Evolution of Communicating the Uncertainty of Climate Change to Policymakers: A Study of IPCC Synthesis Reports

The Intergovernmental Panel on Climate Change (IPCC) reports on climate change have served to alert both the public and policymakers about the scope of the predicted changes and the effects they would have on natural and economic systems. The first IPCC report was published in 1990, since which time a further four have been produced. The aim of this study was to conduct a content analysis of the IPCC Summaries for Policymakers in order to determine the degree of certainty associated with the statements they contain. For each of the reports we analyzed all statements containing expressions indicating the corresponding level of confidence. The aggregated results show a shift over time towards higher certainty levels, implying a “Call to action” (from 32.8% of statements in IPCC2 to 70.2% in IPCC5). With regard to the international agreements drawn up to tackle climate change, the growing level of confidence expressed in the IPCC Summaries for Policymakers reports might have been a relevant factor in the history of decision making.

Following the algorithm: How epidemiological risk-scores do accountability

Epidemiological risk scores are calculative devices that mediate and enact versions of accountability in public health and preventive medicine. This article focuses on practices of accountability by following a cardiovascular risk score widely used in medical counselling in Germany. We follow the risk score in the making, in action, and in circulation to explore how the score performs in doctor-patient relations, how it recombines epidemiological results, and how it shapes knowledge production and healthcare provision. In this way, we follow the risk score's various trajectories - from its development at the intersection of epidemiology, general medicine and software engineering, to its usage in general practitioners' offices, and its validation infrastructures. Exploring the translations from population to individual and back that are at work in the risk score and in the primary prevention of cardiovascular disease, we examine how versions and distributions of accountability are invoked and practiced as the score is developed and put to use. The case of a simple risk score used in everyday counselling brings into relief some key shifts in configurations of accountability with emerging versions of 'health by the algorithm'. While there is an increasing authority of algorithmic tools in the fabric of clinical encounters, risk scores are interwoven with local specificities of the healthcare system and continue to be in the making.

A Balanced Risk-Benefit Analysis to Determine Human Risks Associated with Pyrrolizidine Alkaloids (PA)-The Case of Herbal Medicinal Products Containing St. John's Wort Extracts (SJW)

OBJECTIVES

Pyrrolizidine alkaloids (PA) exist ubiquitously in our environment. More than 6000 plants, about 3% of the world’s flowering plants, are known to synthesize PA. As a consequence, many herbal ingredients, including St. John’s wort (SJW), are contaminated with PA that can possess acute and subchronic toxic effects as well as mutagenic and genotoxic properties. Therefore, the possible benefits of SJW as an herbal remedy against depression need to be weighed against the possible risks of unwanted PA intake.

METHODS

We searched the literature regarding the current knowledge on PA and evaluated the evidence on the antidepressant effects of quantified SJW extract based on a Cochrane Review and the current practice guidelines on depression. Risks are depicted in form of a risk ladder and benefits in form of an icon array.

RESULTS

Evidence from clinical studies indicates that quantified SJW extract is an effective treatment option for mild to moderate depression with fewer side effects than conventional antidepressants. Health statistics from different countries do not quantify cases of death caused by PA intake. However, deaths due to suicide, often triggered by depression, are common (11 in 1000 in Germany in 2015) and rank between fatalities due to liver diseases (16 in 1000) and household accidents (10 in 1000).

CONCLUSIONS

Quantified SJW extract is a safe and effective treatment option, and its potential of treating depression outweighs the (hypothetical) risk of unwanted PA intake.

Visualizing risks in cancer communication: A systematic review of computer-supported visual aids

OBJECTIVE

Health websites are becoming important sources for cancer information. Lay users, patients and carers seek support for critical decisions, but they are prone to common biases when quantitative information is presented. Graphical representations of risk data can facilitate comprehension, and interactive visualizations are popular. This review summarizes the evidence on computer-supported graphs that present risk data and their effects on various measures.

METHODS

The systematic literature search was conducted in several databases, including MEDLINE, EMBASE and CINAHL. Only studies with a controlled design were included. Relevant publications were carefully selected and critically appraised by two reviewers.

RESULTS

Thirteen studies were included. Ten studies evaluated static graphs and three dynamic formats. Most decision scenarios were hypothetical. Static graphs could improve accuracy, comprehension, and behavioural intention. But the results were heterogeneous and inconsistent among the studies. Dynamic formats were not superior or even impaired performance compared to static formats.

CONCLUSIONS

Static graphs show promising but inconsistent results, while research on dynamic visualizations is scarce and must be interpreted cautiously due to methodical limitations.

PRACTICE IMPLICATIONS

Well-designed and context-specific static graphs can support web-based cancer risk communication in particular populations. The application of dynamic formats cannot be recommended and needs further research.

A Balanced Risk-Benefit Analysis to Determine Human Risks Associated with Pyrrolizidine Alkaloids (PA)-The Case of Tea and Herbal Infusions

Humans are exposed to pyrrolizidine alkaloids (PA) through different sources, mainly from contaminated foodstuff. Teas and herbal infusions (T&HI) can be contaminated by PA producing weed. PA can possess toxic, mutagenic, genotoxic, and carcinogenic properties. Thus, possible health risks for the general population are under debate. There is a strong safety record for T&HI and additionally epidemiological evidence for the preventive effects of regular tea consumption on cardiovascular events and certain types of cancer. There is no epidemiological evidence, however, for human risks of regular low dose PA exposure. Recommended regulatory PA-threshold values are based on experimental data only, accepting big uncertainties. If a general risk exists through PA contaminated T&HI, it must be small compared to other frequently accepted risks of daily living and the proven health effects of T&HI. Decision making should be based on a balanced riskbenefit analysis. Based on analyses of the scientific data currently available, it is concluded that the benefits of drinking T&HI clearly outweigh the negligible health risk of possible PA contamination. At the same time, manufacturers must continue their efforts to secure good product quality and to be transparent on their measures of quality control and risk communication.

The effect of bundling medication-assisted treatment for opioid addiction with mHealth: study protocol for a randomized clinical trial

BACKGROUND

Opioid dependence has devastating and increasingly widespread consequences and costs, and the most common outcome of treatment is early relapse. People who inject opioids are also at disproportionate risk for contracting the human immunodeficiency virus (HIV) and hepatitis C virus (HCV). This study tests an approach that has been shown to improve recovery rates: medication along with other supportive services (medication-assisted treatment, or MAT) against MAT combined with a smartphone innovation called A-CHESS (MAT + A-CHESS).

METHODS/DESIGN

This unblinded study will randomly assign 440 patients to receive MAT + A-CHESS or MAT alone. Eligible patients will meet criteria for having an opioid use disorder of at least moderate severity and will be taking methadone, injectable naltrexone, or buprenorphine. Patients with A-CHESS will have smartphones for 16 months; all patients will be followed for 24 months. The primary outcome is the difference between patients in the two arms in percentage of days using illicit opioids during the 24-month intervention. Secondary outcomes are differences between patients receiving MAT + A-CHESS versus MAT in other substance use, quality of life, retention in treatment, health service use, and, related to HIV and HCV, screening and testing rates, medication adherence, risk behaviors, and links to care. We will also examine mediators and moderators of the effects of MAT + A-CHESS. We will measure variables at baseline and months 4, 8, 12, 16, 20, and 24. At each point, patients will respond to a 20- to 30-min phone survey; urine screens will be collected at baseline and up to twice a month thereafter. We will use mixed-effects to evaluate the primary and secondary outcomes, with baseline scores functioning as covariates, treatment condition as a between-subject factor, and the outcomes reflecting scores for a given assessment at the six time points. Separate analyses will be conducted for each outcome.

DISCUSSION

A-CHESS has been shown to improve recovery for people with alcohol dependence. It offers an adaptive and extensive menu of services and can attend to patients nearly as constantly as addiction does. This suggests the possibility of increasing both the effectiveness of, and access to, treatment for opioid dependence.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02712034 . Registered on 14 March 2016.

Using quantitative risk information in decisions about statins: a qualitative study in a community setting

Background

A large literature informs guidance for GPs about communicating quantitative risk information so as to facilitate shared decision making. However, relatively little has been written about how patients utilise such information in practice.

Aim

To understand the role of quantitative risk information in patients’ accounts of decisions about taking statins.

Design and setting

This was a qualitative study, with participants recruited and interviewed in community settings.

Method

Semi-structured interviews were conducted with 34 participants aged >50 years, all of whom had been offered statins. Data were analysed thematically, using elements of the constant comparative method.

Results

Interviewees drew frequently on numerical test results to explain their decisions about preventive medication. In contrast, they seldom mentioned quantitative risk information, and never offered it as a rationale for action. Test results were spoken of as objects of concern despite an often-explicit absence of understanding, so lack of understanding seems unlikely to explain the non-use of risk estimates. Preventive medication was seen as ‘necessary’ either to treat test results, or because of personalised, unequivocal advice from a doctor.

Conclusion

This study’s findings call into question the assumption that people will heed and use numerical risk information once they understand it; these data highlight the need to consider the ways in which different kinds of knowledge are used in practice in everyday contexts. There was little evidence from this study that understanding probabilistic risk information was a necessary or valued condition for making decisions about statin use.

Measuring prevalence, reliability and variation in high-risk prescribing in general practice using multilevel modelling of observational data in a population database

Background

High-risk primary care prescribing is common and is known to vary considerably between practices, but the extent to which high-risk prescribing varies among individual general practitioners (GPs) is not known.

Objectives

To create prescribing safety indicators usable in existing electronic clinical data and to examine (1) variation in high-risk prescribing between patients, GPs and practices including reliability of measurement and (2) changes over time in high-risk prescribing prevalence and variation between practices.

Design

Descriptive analysis and multilevel logistic regression modelling of routine data.

Setting

UK general practice using routine electronic medical record data.

Participants

(1) For analysis of variation and reliability, 398 GPs and 26,539 patients in 38 Scottish practices. (2) For analysis of change in high-risk prescribing, ≈ 300,000 patients particularly vulnerable to adverse drug effects registered with 190 Scottish practices.

Main outcome measures

For the analysis of variation between practices and between GPs, five indicators of high-risk non-steroidal anti-inflammatory drug (NSAID) prescribing. For the analysis of change in high-risk prescribing, 19 previously validated indicators.

Results

Measurement of high-risk prescribing at GP level was feasible only for newly initiated drugs and for drugs similar to NSAIDs which are usually initiated by GPs. There was moderate variation between practices in total high-risk NSAID prescribing [intraclass correlation coefficient (ICC) 0.034], but this indicator was highly reliable (> 0.8 for all practices) at distinguishing between practices because of the large number of patients being measured. There was moderate variation in initiation of high-risk NSAID prescribing between practices (ICC 0.055) and larger variation between GPs (ICC 0.166), but measurement did not reliably distinguish between practices and had reliability > 0.7 for only half of the GPs in the study. Between quarter (Q)2 2004 and Q1 2009, the percentage of patients exposed to high-risk prescribing measured by 17 indicators that could be examined over the whole period fell from 8.5% to 5.2%, which was largely driven by reductions in high-risk NSAID and antiplatelet use. Variation between practices increased for five indicators and decreased for five, with no relationship between change in the rate of high-risk prescribing and change in variation between practices.

Conclusions

High-risk prescribing is common and varies moderately between practices. High-risk prescribing at GP level cannot be easily measured routinely because of the difficulties in accurately identifying which GP actually prescribed the drug and because drug initiation is often a shared responsibility with specialists. For NSAID initiation, there was approximately three times greater variation between GPs than between practices. Most GPs with above average high-risk prescribing worked in practices which were not themselves above average. The observed reductions in high-risk prescribing between 2004 and 2009 were largely driven by falls in NSAID and antiplatelet prescribing, and there was no relationship between change in rate and change in variation between practices. These results are consistent with improvement interventions in all practices being more appropriate than interventions targeted on practices or GPs with higher than average high-risk prescribing. There is a need for research to understand why high-risk prescribing varies and to design and evaluate interventions to reduce it.

Funding

Funding for this study was provided by the Health Services and Delivery Research programme of the National Institute for Health Research.

Cancer risk assessment tools in primary care: a systematic review of randomized controlled trials

PURPOSE

We conducted this review to identify published randomized controlled trials (RCTs) of cancer risk assessment tools used in primary care and to determine their impact on clinical utility (clinicians), screening uptake (patients), and psychosocial outcomes (patients).

METHODS

We searched EMBASE, PubMed and the Cochrane databases for RCTs of cancer risk assessment tools in primary care up to May 2014. Only studies set in primary care, with patients eligible for screening, and English-language articles were included.

RESULTS

The review included 11 trials of 7 risk tools. The trials were heterogeneous with respect to type of tool that was used, type(s) of cancer assessed, and outcomes measured. Evidence suggested risk tools improved patient risk perception, knowledge, and screening intentions, but not necessarily screening behavior. Overall, uptake of a tool was greater if initiated by patients, if used by a dedicated clinician, and when combined with decision support. There was no increase in cancer worry. Health promotion messages within the tool had positive effects on behavior change. Trials were limited by low-recruitment uptake, and the heterogeneity of the findings necessitated a narrative review rather than a meta-analysis.

CONCLUSIONS

Risk tools may increase intentions to have cancer screening, but additional interventions at the clinician or health system levels may be needed to increase risk-appropriate cancer screening behavior.

Violence risk assessment in clinical settings: being sure about being sure

Psychiatrists and psychologists have available structured risk assessment instruments to assess the risk of patient violence. These instruments are also used to help make important legal decisions, including which prisoners will be evaluated for continued detention at the end of their sentence. The predictive validity of structured instruments has been demonstrated in operationally defined groups. Their application to individual cases has led to objections that the standard deviations for the risk categories generated by the instruments overlap significantly. This debate has paid insufficient attention to the differences between aleatory (statistical) and epistemic (degree of confirmation) approaches to uncertainty. The approach to uncertainty in psychiatric violence risk assessment is, of necessity, largely epistemic. Providing statistical data can only be part of establishing the precision of an estimate of the probability of someone acting violently.

Cardiovascular risk

Cardiovascular disease is a major, growing, worldwide problem. It is important that individuals at risk of developing cardiovascular disease can be effectively identified and appropriately stratified according to risk. This review examines what we understand by the term risk, traditional and novel risk factors, clinical scoring systems, and the use of risk for informing prescribing decisions. Many different cardiovascular risk factors have been identified. Established, traditional factors such as ageing are powerful predictors of adverse outcome, and in the case of hypertension and dyslipidaemia are the major targets for therapeutic intervention. Numerous novel biomarkers have also been described, such as inflammatory and genetic markers. These have yet to be shown to be of value in improving risk prediction, but may represent potential therapeutic targets and facilitate more targeted use of existing therapies. Risk factors have been incorporated into several cardiovascular disease prediction algorithms, such as the Framingham equation, SCORE and QRISK. These have relatively poor predictive power, and uncertainties remain with regards to aspects such as choice of equation, different risk thresholds and the roles of relative risk, lifetime risk and reversible factors in identifying and treating at-risk individuals. Nonetheless, such scores provide objective and transparent means of quantifying risk and their integration into therapeutic guidelines enables equitable and cost-effective distribution of health service resources and improves the consistency and quality of clinical decision making.

Tinkering and tailoring individual consultations: how practice nurses try to make cardiovascular risk communication meaningful

AIMS AND OBJECTIVES

To explore the perspectives of practice nurses in their role of communicating cardiovascular risk to patients.

BACKGROUND

Nurses in primary care have for some time been engaged in cardiovascular risk discussions with patients. With the recent introduction of the NHS Health Checks, the focus on this work is set to increase.

DESIGN

Qualitative using a framework approach.

METHODS

Two focus groups and 16 semi-structured interviews were conducted with nurses purposively sampled from those working in primary care.

RESULTS

The nurses' accounts revealed the need to develop a relationship of trust and establish a level of relevance with each individual patient whilst discussing cardiovascular risk. Potential aspects of these discussions were as follows: working within a highly structured data-collecting task; time constraints and consideration of the individual's context. We used the idea of tailoring to describe how nurses navigate and constantly modify and pitch their approach for each patient they see in response to these constraints.

CONCLUSION

We suggest that in order for risk to be made meaningful to patients, practice nurses recognise the need for such information to be embedded in the more reciprocal dynamics of nurse-patient consultations. From their perspective, success is often as much about not saying something, or saying it in a particular way, as saying anything accurately or consistently.

RELEVANCE TO CLINICAL PRACTICE

For practice nurses to be instrumental in the successful delivery of health prevention policy initiatives such as the NHS Health Checks, it is important to acknowledge their views and perspectives in undertaking this work. This study suggests that the nurses recognised the need for further skills and a refinement of approach for those health professionals involved.

Varieties of uncertainty in health care: a conceptual taxonomy

Uncertainty is a pervasive and important problem that has attracted increasing attention in health care, given the growing emphasis on evidence-based medicine, shared decision making, and patient-centered care. However, our understanding of this problem is limited, in part because of the absence of a unified, coherent concept of uncertainty. There are multiple meanings and varieties of uncertainty in health care that are not often distinguished or acknowledged although each may have unique effects or warrant different courses of action. The literature on uncertainty in health care is thus fragmented, and existing insights have been incompletely translated to clinical practice. This article addresses this problem by synthesizing diverse theoretical and empirical literature from the fields of communication, decision science, engineering, health services research, and psychology and developing a new integrative conceptual taxonomy of uncertainty. A 3-dimensional taxonomy is proposed that characterizes uncertainty in health care according to its fundamental sources, issues, and locus. It is shown how this new taxonomy facilitates an organized approach to the problem of uncertainty in health care by clarifying its nature and prognosis and suggesting appropriate strategies for its analysis and management.

Why two smoking cessation agents work better than one: role of craving suppression

OBJECTIVE

This research examined why smokers receiving combination medication for smoking cessation are more likely to quit smoking than are those who receive either single agent (monotherapy) or placebo.

METHOD

Data were collected from 1,504 current smokers (58.2% women, 83.9% White; mean age = 44.67 years, SD = 11.08) participating in a cessation clinical trial who were randomized to 1 of 6 cessation pharmacotherapy conditions (placebo, nicotine patch, nicotine lozenge, bupropion, nicotine patch + nicotine lozenge, and bupropion + nicotine lozenge). Participants completed ecological momentary assessments 4 times a day, concerning 5 hypothesized mediators (negative affect, positive affect, craving, smoking expectations, and withdrawal) of pharmacotherapy effects. Medications were provided for 8-12 weeks post-quit along with 6 individual counseling sessions. Mediational paths were estimated via a novel Bayesian approach with estimation of multiple mediator models.

RESULTS

Biochemically confirmed 8-week abstinence was the outcome variable, with the monotherapy and combination pharmacotherapy composites producing 45% (n = 689) and 54% (n = 478) abstinence rates, respectively. The univariate models suggested that the combination treatments produced higher abstinence rates than the monotherapies because of greater suppression of withdrawal, craving, and smoking expectations. However, multiple mediator models showed that the suppression of craving on the quit day produced the strongest mediational effects and could account for the mediational effects of other tested variables.

CONCLUSION

Suppression of craving on the quit day significantly mediates the clinical effects of monotherapies and combination smoking pharmacotherapies, and the higher abstinence rates for combination therapy versus monotherapies appear primarily due to greater craving suppression.

Risk of placenta previa in second birth after first birth cesarean section: a population-based study and meta-analysis

BACKGROUND

OBJECTIVE

To compare the risk of placenta previa at second birth among women who had a cesarean section (CS) at first birth with women who delivered vaginally.

METHODS

Retrospective cohort study of 399,674 women who gave birth to a singleton first and second baby between April 2000 and February 2009 in England. Multiple logistic regression was used to adjust the estimates for maternal age, ethnicity, deprivation, placenta previa at first birth, inter-birth interval and pregnancy complications. In addition, we conducted a meta-analysis of the reported results in peer-reviewed articles since 1980.

RESULTS

The rate of placenta previa at second birth for women with vaginal first births was 4.4 per 1000 births, compared to 8.7 per 1000 births for women with CS at first birth. After adjustment, CS at first birth remained associated with an increased risk of placenta previa (odds ratio = 1.60; 95% CI 1.44 to 1.76). In the meta-analysis of 37 previously published studies from 21 countries, the overall pooled random effects odds ratio was 2.20 (95% CI 1.96-2.46). Our results from the current study is consistent with those of the meta-analysis as the pooled odds ratio for the six population-based cohort studies that analyzed second births only was 1.51 (95% CI 1.39-1.65).

CONCLUSIONS

There is an increased risk of placenta previa in the subsequent pregnancy after CS delivery at first birth, but the risk is lower than previously estimated. Given the placenta previa rate in England and the adjusted effect of previous CS, 359 deliveries by CS at first birth would result in one additional case of placenta previa in the next pregnancy.

The effects of absolute risks, relative risks, frequencies, and probabilities on decision quality

It is important to understand how the quality of people's decision making may be affected by the format used to present treatment benefits. Two experiments compared the accuracy of presenting the benefits of cancer screening tests or vaccines using either absolute or relative risk formats that included baseline risk information. Moreover, the absolute and/or baseline risks were presented using either natural frequencies or probabilities. In both experiments, accuracy was measured by the sensitivity of choices to differences in absolute rather than relative risks. Experiment 1 showed no significant differences in sensitivity between the relative and absolute risk formats when the risks were presented as natural frequencies. Sensitivity was, however, poor in both probability versions. Experiment 2 tested the natural frequency versions more stringently by presenting choices with different levels of difficulty. The author found that decision quality was significantly less affected by increases in difficulty in the absolute risk format. Presenting baseline risks using natural frequencies may help to reduce the biasing effects of relative risks but decision quality may not be on a par with the accuracy of decisions made when absolute risks are presented in natural frequency formats.

Dissemination of drinking water contamination data to consumers: a systematic review of impact on consumer behaviors

BACKGROUND

Drinking water contaminated by chemicals or pathogens is a major public health threat in the developing world. Responses to this threat often require water consumers (households or communities) to improve their own management or treatment of water. One approach hypothesized to increase such positive behaviors is increasing knowledge of the risks of unsafe water through the dissemination of water contamination data. This paper reviews the evidence for this approach in changing behavior and subsequent health outcomes.

METHODS/PRINCIPAL FINDINGS

A systematic review was conducted for studies where results of tests for contaminants in drinking water were disseminated to populations whose water supply posed a known health risk. Studies of any design were included where data were available from a contemporaneous comparison or control group. Using multiple sources >14,000 documents were located. Six studies met inclusion criteria (four of arsenic contamination and two of microbiological contamination). Meta-analysis was not possible in most cases due to heterogeneity of outcomes and study designs. Outcomes included water quality, change of water source, treatment of water, knowledge of contamination, and urinary arsenic. Source switching was most frequently reported: of 5 reporting studies 4 report significantly higher rates of switching (26-72%) among those who received a positive test result and a pooled risk difference was calculate for 2 studies (RD = 0.43 [CI0.4.0-0.46] 6-12 months post intervention) suggesting 43% more of those with unsafe wells switched source compared to those with safe wells. Strength of evidence is low since the comparison is between non-equivalent groups. Two studies concerning fecal contamination reported non-significant increases in point-of-use water treatment.

CONCLUSION

Despite the publication of some large cohort studies and some encouraging results the evidence base to support dissemination of contamination data to improve water management is currently equivocal. Rigorous studies on this topic are needed, ideally using common outcome measures.

Varieties of Uncertainty in Health Care

Uncertainty is a pervasive and important problem that has attracted increasing attention in health care, given the growing emphasis on evidence-based medicine, shared decision making, and patient-centered care. However, our understanding of this problem is limited, in part because of the absence of a unified, coherent concept of uncertainty. There are multiple meanings and varieties of uncertainty in health care that are not often distinguished or acknowledged although each may have unique effects or warrant different courses of action. The literature on uncertainty in health care is thus fragmented, and existing insights have been incompletely translated to clinical practice. This article addresses this problem by synthesizing diverse theoretical and empirical literature from the fields of communication, decision science, engineering, health services research, and psychology and developing a new integrative conceptual taxonomy of uncertainty. A 3-dimensional taxonomy is proposed that characterizes uncertainty in health care according to its fundamental sources, issues, and locus. It is shown how this new taxonomy facilitates an organized approach to the problem of uncertainty in health care by clarifying its nature and prognosis and suggesting appropriate strategies for its analysis and management.

When a man thinks he has female traits--constructing femininity and masculinity: methodological potentials and limitations

In everyday life, people are confronted with common beliefs about how women and men differ from each other. These beliefs make them wonder about their personal femininity and masculinity. But what hides behind these constructs? In this article, we will discuss the potential and limitations of different definitions. We will focus on methodological issues which can trigger new discussions about the social implications of gender differences-which are not part of this paper. One of the major questions here is whether it is methodologically justifiable (legitimate) to make individual predictions based on group differences. An issue that is not only relevant in regards to femininity and masculinity. In general, all definitions of masculinity and femininity show more limitations than potentials. They are either neglecting certain sub-groups or are based on stereotypes (either displaying common beliefs or exaggerated group differences). Individual predictions derived from these constructs are questionable due to oversimplification/reductionism (e.g., when forming groups). By pointing out that constructs like femininity and masculinity can in fact limit an individual's development, it is suggested to clearly differentiate between different types of differences and to clearly state what can and cannot be said when "measuring" an individual's masculinity and femininity. Since femininity and masculinity can be seen as example constructs, and generalizations are part of many research processes, general implications beyond these concepts are being discussed.