The Application of Non-Default Uncertainty Factors in the U.S. EPA's Integrated Risk Information System (IRIS). Part I: UF L,UF S,and “Other Uncertainty Factors”

The United States Environmental Protection Agency's Integrated Risk Information System (IRIS) includes hazard identification and dose-response assessment values developed by Agency scientists. Uncertainty factors (UFs) are used in the development of IRIS values to address the lack of information in five main areas. The standard UFs account for interspecies uncertainty (UF_A) and intraspecies variability (UF_H). The UF_A addresses uncertainty related to the extrapolation of data from animals to humans, whereas the UF_H addresses variability amongst individuals (i.e., intrahuman). Additional UFs have been employed to account for database incompleteness, extrapolations from a lowest-observed-adverse-effect level in the absence of a no-observed-adverse-effect level (UF_L), and subchronic-to-chronic extrapolation (UF_S). A sixth UF designated as “other uncertainty factors” (UF_O) has also been applied in place of the UF_L to account for uncertainty with the adversity of points of departure obtained using benchmark dose modeling. This review will discuss how UF_L, UF_S, and UF_O have been applied in IRIS assessments, along with the rationale used to describe the choice of UF values that deviate from the standard default of 10.     

Shape and mechanics in thalattosuchian (Crocodylomorpha) skulls: implications for feeding behaviour and niche partitioning

Variation in modern crocodilian and extinct thalattosuchian crocodylomorph skull morphology is only weakly correlated with phylogeny, implying that factors other than evolutionary proximity play important roles in determining crocodile skull shape. To further explore factors potentially influencing morphological differentiation within the Thalattosuchia, we examine teleosaurid and metriorhynchid skull shape variation within a mechanical and dietary context using a combination of finite element modelling and multivariate statistics. Patterns of stress distribution through the skull were found to be very similar in teleosaurid and metriorhynchid species, with stress peaking at the posterior constriction of the snout and around the enlarged supratemporal fenestrae. However, the magnitudes of stresses differ, with metriorhynchids having generally stronger skulls. As with modern crocodilians, a strong linear relationship between skull length and skull strength exists, with short‐snouted morphotypes experiencing less stress through the skull than long‐snouted morphotypes under equivalent loads. Selection on snout shape related to dietary preference was found to work in orthogonal directions in the two families: diet is associated with snout length in teleosaurids and with snout width in metriorhynchids, suggesting that teleosaurid skulls were adapted for speed of attack and metriorhynchid skulls for force production. Evidence also indicates that morphological and functional differentiation of the skull occurred as a result of dietary preference, allowing closely related sympatric species to exploit a limited environment. Comparisons of the mechanical performance of the thalattosuchian skull with extant crocodilians show that teleosaurids and long‐snouted metriorhynchids exhibit stress magnitudes similar to or greater than those of long‐snouted modern forms, whereas short‐snouted metriorhynchids display stress magnitudes converging on those found in short‐snouted modern species. As a result, teleosaurids and long‐snouted metriorhynchids were probably restricted to lateral attacks of the head and neck, but short‐snouted metriorhynchids may have been able to employ the grasp and shake and/or ‘death roll’ feeding and foraging behaviours.     

An Assessment of Dental Treatment Need: An Overview of Available Methods and Suggestions for a New, Comparative Summative Index

Objective: The aims were to give an overview and consider advantages and disadvantages of different approaches used to evaluate dental treatment need and to suggest an alternate Quantitative Summative Dental Treatment Need Index. Methods: The Medline Ovid database was searched for relevant articles published during the last three decades combining the terms "needs assessment,""dental care,""health services needs and demand." Results: There were substantial differences in methods used. Different modifications of the Decayed, Missing, Filled Teeth/Surfaces indices, complex quantitative summative indices, or simplified approaches were used to assess dental treatment need. Differing advantages and disadvantages of these methods can be identified. Previously used approaches have a common limitation for use in oral epidemiology. Conclusions: The suggested alternate Quantitative Summative Dental Treatment Needs Index focuses on an ability to compare both the total burden of treatment need as well as to make a distinction among specific treatment needs across populations. This new approach is an attempt to develop a comprehensive index for use in oral epidemiology with further revisions anticipated.     

Long term outcome of elective day case percutaneous coronary intervention in patients with stable angina

Patients undergoing elective PCI are traditionally admitted overnight, however day case PCI cuts costs and has been proposed as a safe method for selected patients. We evaluated the success and long term clinical outcomes of day case percutaneous coronary intervention (PCI) for outpatients with stable angina.In total, 484 consecutive patients treated over a five year period with planned day case PCI were studied and followed up for 12 months. Successful PCI with same day discharge was performed in 463 patients (95.7%). There were 21 patients (4.3%) who required hospital admission. Reasons for failed discharge were hematoma formation (n = 7, 1.4%), coronary dissection (n = 4, 0.8%), post-procedural chest pain (n = 3, 0.6%), prolonged procedure (n = 2, 0.4%), and 1 each of acute stent thrombosis, coronary perforation, anaphylaxis, minor drug reaction and a functional study for untreated disease. One year follow up was complete for 439/484 (90.7%). At 12 months there were 6 hospitalizations for angina (1.2%, 95% CI 0.6–3.0%), 20 repeat revascularisations (4.1%, 95% CI 2.7–6.3%), 3 myocardial infarctions (0.6%, 95% CI 0.2–2.1%) and 2 deaths (0.4%, 95% CI 0.1–1.6%). Event free survival at 1 year follow up was 93.6% (95% CI 90.7–95.6%).Selecting patients for day case PCI is safe, and can achieve a high rate of success with excellent long term outcomes.     

A randomised study of outcomes in a defined group of acutely ill elderly patients managed in a geriatric assessment unit or a general medical unit

The aim of this study was to identify differences in the medical management and clinical outcome in a group of elderly patients admitted to a designated geriatric assessment unit (GAU) or to two general medical units (GMUs). A prospective randomised controlled trial was undertaken in 267 patients aged 70 years and over (mean age = 78.3 years). Following discharge from hospital, patients were followed up at three monthly intervals for a total of 12 months. At the time of discharge, no significant differences were found in inpatient management, length of stay, mortality rates, discharge rates to institutional care or utilisation of community services in patients admitted to the GAU and the GMUs. Similarly, no significant differences were found at three, six, nine, and 12 month follow up in case fatality, activities of daily living indices, mental health status, rates of institutional referral and the level of community service support in patients admitted to the GAU and the GMUs studied. These findings do not show any advantage for the unselected 70 + acutely ill elderly patient who is admitted to a designated geriatric assessment unit rather than to a general medical unit. Therefore, an admission policy to GAU, based solely on age 70 + is medically inappropriate and cost-inefficient. Evidence from other sources suggests that an age cohort of acutely admitted patients beyond 80 years may well have returned more optimistic findings for the GAU. In future, GAUs will require a more selective admission policy to maximise the benefits of their rehabilitative and interdisciplinary approach. (Aust NZ J Med 1991; 21: 230–234.)     

国人缺血性心血管病发病危险的评估方法及简易评估工具的开发研究

目的 研究开发适合我国人群疾病特点且方便临床使用的心血管病发病危险度评估方法和评估工具。方法 依据中美心肺血管疾病流行病学合作研究队列随访资料，采用Cox比例风险模型拟合最优预测模型，并校正人群危险因素长期变化趋势的影响，采用独立人群回代检验和计算ROC曲线下面积来检验模型的预测能力。进一步建立简易预测模型，并据此制定适合我国人群的心血管病综合危险度简易评估工具。结果 中美心肺血管疾病流行病学合作研究1983～1984年基线调查年龄35～59岁，剔除基线患有冠心病、脑卒中及主要危险因素资料不全者后男女共计9903人，截止到2000年平均随访15．1年，共发生冠心病事件105例、缺血性脑卒中266例、缺血性心血管病360例。基线年龄、性别、血压、血清总胆固醇、体重指数、吸烟和糖尿病与冠心病、缺血性脑卒中和缺血性心血管病(ischemic cardiovascular diseases，ICVD)事件发病有互相独立的显著关联，且联系的方向和规律一致。据此建立的分性别ICVD事件10年发病危险预测模型，经过校正人群危险因素的长期变化趋势，证明能够很好地用于1992～1994年新建立队列的ICVD发病预测，其ROC曲线下面积(AUC)男性最优模型为0．799，女性最优模型为0．844。简易模型的AUC与最优模型几乎相同。结论 初步开发的ICVD事件10年发病危险预测模型和简易评估工具具有令人满意的预测能力，也能够较好地反映国人发生心血管病的综合危险。     

Patient acceptable symptom state and minimal clinically important difference for patient-reported outcomes in systemic sclerosis: A secondary analysis of a randomized controlled trial comparing personalized physical therapy to usual care

Background

To estimate patient acceptable symptom state (PASS) and minimal clinically important difference (MCID) for patient-reported outcomes in systemic sclerosis (SSc).