Imputing Risk Tolerance from Survey Responses

Economic theory assigns a central role to risk preferences. This paper develops a measure of relative risk tolerance using responses to hypothetical income gambles in the Health and Retirement Study. In contrast to most survey measures that produce an ordinal metric, this paper shows how to construct a cardinal proxy for the risk tolerance of each survey respondent. The paper also shows how to account for measurement error in estimating this proxy and how to obtain consistent regression estimates despite the measurement error. The risk tolerance proxy is shown to explain differences in asset allocation across households.

Monitoring aquifer recharge using repeated high-precision gravity measurements: a pilot study in South Weber, Utah

Journal ArticleRepeated high-precision gravity surveys were conducted over two infiltration cycles on an alluvial-fan aquifer system at the mouth of Weber Canyon in northern Utah as part of the Weber River Basin Aquifer Storage and Recovery Pilot Project (WRBASR). Gravity measurements collected before, during, and after infiltration events indicate that a perched groundwater mound formed during infiltration events and decayed smoothly following infiltration. Data also suggest the groundwater mound migrated gradually south-southwest from the surface infiltration site

Competition of fusion and quasi-fission in the reactions leading to production of the superheavy elements

The mechanism of fusion hindrance, an effect observed in the reactions of cold, warm and hot fusion leading to production of the superheavy elements, is investigated. A systematics of transfermium production cross sections is used to determine fusion probabilities. Mechanism of fusion hindrance is described as a competition of fusion and quasi-fission. Available evaporation residue cross sections in the superheavy region are reproduced satisfactorily. Analysis of the measured capture cross sections is performed and a sudden disappearance of the capture cross sections is observed at low fusion probabilities. A dependence of the fusion hindrance on the asymmetry of the projectile-target system is investigated using the available data. The most promising pathways for further experiments are suggested.Comment: 8 pages, 7 figures, talk presented at 7th International School-Seminar on Heavy-Ion Physics, May 27 - June 1, 2002, Dubna, Russi

Risk Preferences in the PSID: Individual Imputations and Family Covariation

Survey measures of preference parameters provide a means for accounting for otherwise unobserved heterogeneity.This paper presents measures of relative risk tolerance based on responses to survey questions about hypothetical gambles over lifetime income.It discusses how to impute estimates of utility function parameters from the survey responses using a statistical model that accounts for survey response error. There is substantial heterogeneity in true preference parameters even after survey response error is taken into account.The paper discusses how to use the preference parameters imputed from the survey responses in regression models as a control for differences in preferences across individuals. This paper focuses on imputations for respondents in the Panel Study of Income Dynamics (PSID).It also studies the covariation of risk preferences among members of households.It finds fairly strong covariation in attitudes about risk -- between parents and children and especially between siblings and between spouses.

Prevalence of antimicrobial resistance in bacteria isolated from central nervous system specimens as reported by U.S. hospital laboratories from 2000 to 2002

BACKGROUND: Bacterial infections of the central nervous system, especially acute infections such as bacterial meningitis require immediate, invariably empiric antibiotic therapy. The widespread emergence of resistance among bacterial species is a cause for concern. Current antibacterial susceptibility data among central nervous system (CNS) pathogens is important to define current prevalence of resistance. METHODS: Antimicrobial susceptibility of pathogens isolated from CNS specimens was analyzed using The Surveillance Database (TSN(®)) USA Database which gathers routine antibiotic susceptibility data from >300 US hospital laboratories. A total of 6029 organisms derived from CNS specimen sources during 2000–2002, were isolated and susceptibility tested. RESULTS: Staphylococcus aureus (23.7%) and Streptococcus pneumoniae (11.0%) were the most common gram-positive pathogens. Gram-negative species comprised approximately 25% of isolates. The modal patient age was 1 or <1 year for most organisms. Prevalence of MRSA among S. aureus from cerebrospinal fluid (CSF) and brain abscesses were 29.9–32.9%. Penicillin resistance rates were 16.6% for S. pneumoniae, 5.3% for viridans group streptococci, and 0% for S. agalactiae. For CSF isolates, ceftriaxone resistance was S. pneumoniae (3.5%), E. coli (0.6%), Klebsiella pneumoniae (2.8%), Serratia marcescens (5.6%), Enterobacter cloacae (25.0%), Haemophilus influenzae (0%). Listeria monocytogenes and N. meningitidis are not routinely susceptibility tested. CONCLUSIONS: Resistance is commonly detected, albeit still at relatively low levels for key drugs classes such as third-generation cephalosporins. This data demonstrates the need to consider predominant resistance phenotypes when choosing empiric therapies to treat CNS infections

Inconclusiveness of psychometric testing of medication adherence questionnaires

Purpose To propose a paradigm change for the validation procedures of medication adherence questionnaires. Methods A total of 121 validation procedures of unique questionnaires for medication adherence were analyzed. Results “Construct validity” and “internal consistency” were most often assessed, and test results varied largely. A more in-depth analysis indicated that the assessment of medication non-adherence included distinct but related constructs, such as the extent to which doses are missed, and the attempt to identify different facets of medication-taking behavior. Consequently, each construct requires a different measurement approach with different psychometric tests for establishing its validity and reliability. Conclusion Results show that assessing the validity and reliability of adherence questionnaires with standard procedures including statistical tests is inconclusive. Refinement of the constructs of non-adherence is needed in pharmacy and medical practice. We suggest a distinction between the (i) extent of missed doses over the past 2 weeks, (ii) modifiable reasons for non-adherence behavior, and (iii) unmodifiable factors of non-adherence. Validation procedures and corresponding statistical methods should be selected according to the specific single constructs

Ceramic matrix composite turbine engine vane

A vane has an airfoil shell and a spar within the shell. The vane has an outboard shroud at an outboard end of the shell and an inboard platform at an inboard end of the shell. The spar has a first chamber essentially along the suction side and a second chamber along the pressure side opposite the first chamber

Development and validation of the 15-STARS - A novel self-report pharmacy-based questionnaire to screen for medication non-adherence

Background Published scales measuring medication adherence are myriad. There is a need for a tool that guides towards downstream adherence interventions. Objective To develop and validate a self-report questionnaire able to detect modifiable determinants of medication non-adherence. Methods Workshops, surveys and meetings were used to identify items. Validation was performed in French and German (Switzerland) between March and April 2022. Face validation, content validation, construct validation, internal consistency and test-retest reliability were assessed. The questionnaire was finalized in August 2022. Results The first draft in English included 13 items divided into four areas. Following translation, validation was performed with 144 patients (63 German-, 81 French-speaking) who were recruited in 35 community pharmacies. Acceptability was good (<5% missing data). Psychometric properties were acceptable with good content validity and moderate construct validity. Internal consistency was acceptable for the French version (Cronbach’s alpha = 0.71 [item 1–5] - 0.61 [item 6–9]) and less acceptable for the German version (Cronbach’s alpha = 0.43 [item 1–5] - 0.45 [item 6–9]). Test-retest was given for all items (r = 0.52 to 1.0) except item 10 in French (r = 0.25). The final instrument is a 15-item questionnaire called the 15-STARS (Screening Tool for AdheRence to medicineS) that assesses practical difficulties with medicine use, reasons for non-adherence, doses missed, and need for further help. Conclusions Our findings support the validity and clinical utility of the 15-STARS questionnaire. Reliability was inconclusive due to incoherent internal consistency, but explainable by the single-item nature of the scale. This new tool will enable the detection of patients who experience difficulties that negatively influence medication adherence. Pharmacists will be able to propose specific and tailored adherence interventions to the patients. Next steps will focus on evaluating its usefulness for developing targeted interventions that optimize medication adherence in routine care and research settings