A weight of evidence approach to causal inference

ObjectiveThe Bradford Hill criteria are the best available criteria for causal inference. However, there is no information on how the criteria should be weighed and they cannot be combined into one probability estimate for causality. Our objective is to provide an empirical basis for weighing the Bradford Hill criteria and to develop a transparent method to estimate the probability for causality.Study Design and SettingAll 159 agents classified by International Agency for Research of Cancer as category 1 or 2A carcinogens were evaluated by applying the nine Bradford Hill criteria. Discriminant analysis was used to estimate the weights for each of the nine Bradford Hill criteria.ResultsThe discriminant analysis yielded weights for the nine causality criteria. These weights were used to combine the nine criteria into one overall assessment of the probability that an association is causal. The criteria strength, consistency of the association and experimental evidence were the three criteria with the largest impact. The model correctly predicted 130 of the 159 (81.8%) agents.ConclusionThe proposed approach enables using the Bradford Hill criteria in a quantitative manner resulting in a probability estimate of the probability that an association is causal.     

Contrasting case definitions for chronic fatigue syndrome, Myalgic Encephalomyelitis/chronic fatigue syndrome and myalgic encephalomyelitis

This article uses data from patients recruited using the 1994 case definition of chronic fatigue syndrome (CFS) to contrast those meeting criteria for the Myalgic Encephalomyelitis/chronic fatigue syndrome (ME/CFS) Canadian case definition with those that did not meet these criteria. The study also contrasts those meeting criteria for Myalgic Encephalomyelitis (ME) based on criteria from Ramsay and other theorists with those that did not meet the ME criteria. The ME/CFS case definition criteria identified a subset of patients with more functional impairments and physical, mental, and cognitive problems than the subset not meeting these criteria. The ME subset had more functional impairments, and more severe physical and cognitive symptoms than the subset not meeting ME criteria. When applied to a population meeting the 1994 CFS case definition, both ME/CFS and ME criteria appear to select a more severe subset of patients.     

Comparability of old and new World Health Organization criteria for definite myocardial infarction

New epidemiological criteria for definite myocardial infarction are now in use as part of the international study of trends and determinants of cardiovascular disease coordinated by the World Health Organization (MONICA Project). In this paper we use data from a myocardial infarction register to assess the comparability of the old and new World Health Organization criteria for definite myocardial infarction. The new criteria were applied to 905 cases who had been categorized as definite myocardial infarction on the old criteria. 739 (82%) of these cases met the new criteria for definite myocardial infarction; a further 157 cases (17%) met the new criteria for possible myocardial infarction. This study indicates that the two sets of criteria produce results that are too dissimilar for reliable comparisons to be made between studies using different criteria for definite myocardial infarction.     

Developing nutrient criteria for food-specific dietary guidelines for the general public

Consumers are asking for specific information about which foods and, in particular, which brands of packaged foods to choose when they eat or purchase food. Point-of-purchase nutrition intervention programs that identify specific foods in restaurants and grocery stores are particularly promising community-based strategies for providing that type of information. However, such strategies demand consistent criteria for determining which foods and/or products should be labeled. This article describes the process of developing and validating criteria and the subsequent uses of the criteria in community nutrition intervention programs. Steps in the process include (a) identifying the scientific basis for the criteria, (b) developing food-group-specific nutrient criteria based on a referent meal pattern, (c) developing the eligibility of single servings of specific foods for labeling based on the nutrient criteria of the food group to which the specific food belongs, and (d) validating the criteria by reviewing actual food products in the grocery stores and restaurants. We conclude that the use of criteria provides a consistent standard for evaluating specific foods and food items in nutrition evaluation programs.     

New Zealand and United Kingdom experiences with the RAND modified Delphi approach to producing angina and heart failure criteria for quality assessment in general practice

OBJECTIVES: (1) To describe the development of minimum review criteria for the general practice management in New Zealand (NZ) of two chronic diseases: stable angina and systolic heart failure, and (2) to compare the NZ angina criteria with a set produced in Manchester to assess the extent to which use of the same approach to criteria development yields similar criteria. METHODS: A modified Delphi approach, based on the RAND consensus panel method, was used to produce minimum criteria for reviewing the recorded management of heart failure and angina in NZ general practice. The criteria for angina were compared with those produced in the UK, including assessment of the extent to which each set describes actions that the other panel agrees are necessary to record. RESULTS: For each condition we report minimum criteria describing actions rated as (a) necessary to record and (b) inappropriate to take but, if taken, necessary to record. Although strong scientific evidence underpins approximately one quarter and one third, respectively, of the final sets of NZ and UK angina criteria for actions necessary to record, the NZ criteria agree strongly with the UK criteria (33 of 39 criteria, 85%) but there is less UK agreement with the NZ angina criteria (28 of 40 criteria, 70%). CONCLUSION: Despite the lack of scientific evidence for up to three quarters of angina care in general practice, the RAND based approach to criteria development was used in NZ to reproduce most of the UK angina criteria for actions rated as necessary to record in general practice. It is important to make explicit whether ratings of necessity and appropriateness apply to the recording of actions or to the actions themselves.     

Physician attitudes, self-estimated performance and actual compliance with locally peer-defined quality evaluation criteria.

BACKGROUND: Physicians' agreement with quality evaluation criteria, and estimates of their own and their colleagues' compliance with these criteria were compared with actual compliance. METHODS: Physicians practicing in 10 health centers in Spain defined 13 quality evaluation criteria for two patient conditions (upper respiratory infections and high serum cholesterol). Compliance with criteria was measured by an external team, using random samples of medical records stratified by condition in each health center (n= 1,000). Concurrently, physicians were surveyed regarding agreement with the criteria, and were asked to estimate their own and their health center's rate of compliance with these criteria. RESULTS: Agreement ratings varied from 5.9 to 9.1 on a 10-point scale. Actual compliance rates ranged from 1.8 to 91.7% of records. Agreement correlated significantly with self-reported compliance but not with actual compliance. Estimates of one's own and one's health center compliance were positive and significantly correlated for all criteria, but were significantly higher for oneself than for one's health center for six of 13 criteria. CONCLUSIONS: Wide variation in physicians' agreement on quality criteria and in actual performance reveal a lack of clear guidelines. Agreement on criteria did not always translate into compliance with criteria. Physicians tended to rate their own performance as better than the average of their peers, suggesting that aggregate data may not influence physicians to change. Self-estimate of one's own or one's colleagues performance is not a good proxy for actual performance so that peer ratings are of dubious value for performance appraisal.     

Appropriateness of coronary revascularization for patients with chronic stable angina or following an acute myocardial infarction: multinational versus Dutch criteria.

OBJECTIVE: We convened a multinational panel to develop appropriateness criteria for percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass graft (CABG). To assess the applicability of these criteria, we applied them to patients referred for coronary revascularization. Finally, to understand how multinational criteria may differ from criteria developed by a panel of physicians from one country, we compared the appropriateness ratings using the multinational panel's criteria and those made using similar criteria previously developed by a panel of Dutch physicians. METHODS: We conducted a prospective survey and review of the medical records of 2363 consecutive patients presenting with chronic stable angina or following a myocardial infarction who were referred for PTCA (n=1137) or CABG (n= 1226) at ten Dutch hospitals performing coronary revascularization. Appropriateness was measured using two sets of criteria developed by: (1) a Dutch panel of cardiologists and cardiothoracic surgeons in 1991; and (2) a similarly composed European panel in 1998. RESULTS: More PTCA referrals were rated inappropriate by Dutch criteria compared with multinational criteria among both patients with chronic stable angina (34.8 versus 6.1%; P< 0.001) and those with a recent myocardial infarction (28.1 versus 0.9%; P< 0.001). Among those patients referred for bypass surgery, the Dutch criteria judged a greater proportion of cases inappropriate than multinational criteria did for patients with chronic stable angina (3.7 versus 1.5%, P< 0.001). The proportion of cases rated inappropriate for bypass surgery among patients following a myocardial infarction was similar between the two panels (3.9 versus 2.4%, respectively; P=0.40). After reclassifying the data for two of the clinical factors used in the appropriateness criteria (lesion morphology and intensity of medical therapy) based on evidence that appeared in the literature after the Dutch panel met, we found no significant differences between the Dutch and multinational panels' appropriateness ratings. CONCLUSIONS: While fewer cases were judged inappropriate using the multinational criteria compared with the Dutch criteria, the differences in ratings were related primarily to the clinical factors used by each panel. These findings support the review of appropriateness criteria, and other forms of clinical guidelines, to ensure that they are current with the clinical evidence before using them to assess clinical care. Developing such criteria using a multinational panel, in contrast to multiple single country panels, would be a more efficient use of resources.     

男同性恋基数估计中认定标准的探讨

目的 探讨适合于男同性恋人群基数估计的男同性恋认定标准。方法 通过小组访谈制定一套具有可操作性的男同性恋认定标准，通过现场实施确认和完善。结果 小组访谈确立了7条识别标准．“眼神”、“外形”和“行为举止”三条标准在现场确认中应用最多，在志愿评分中分别列l、2、4位。结论 在男同性恋人群基数估计中制定一套识别标准可使计数结果达到标准化；本套标准中部分条目仅适用于特定场所，具体场所应制定相应的认定标准。     

Quality criteria were proposed for measurement properties of health status questionnaires

OBJECTIVES: Recently, an increasing number of systematic reviews have been published in which the measurement properties of health status questionnaires are compared. For a meaningful comparison, quality criteria for measurement properties are needed. Our aim was to develop quality criteria for design, methods, and outcomes of studies on the development and evaluation of health status questionnaires. STUDY DESIGN AND SETTING: Quality criteria for content validity, internal consistency, criterion validity, construct validity, reproducibility, longitudinal validity, responsiveness, floor and ceiling effects, and interpretability were derived from existing guidelines and consensus within our research group. RESULTS: For each measurement property a criterion was defined for a positive, negative, or indeterminate rating, depending on the design, methods, and outcomes of the validation study. CONCLUSION: Our criteria make a substantial contribution toward defining explicit quality criteria for measurement properties of health status questionnaires. Our criteria can be used in systematic reviews of health status questionnaires, to detect shortcomings and gaps in knowledge of measurement properties, and to design validation studies. The future challenge will be to refine and complete the criteria and to reach broad consensus, especially on quality criteria for good measurement properties.     

New perspectives on adoption revelation †

An issue of international concern in early-childhood education is the question: To what extent should criteria or standards for evaluating the success of early-childhood education-programs be universal #opapplicable to programs any place at any time#cp and to what extent should criteria be culture specific #opsuitable for some societies but not for others#cp? This paper suggests an answer by means of a scheme for categorizing criteria on two tiers. Universal criteria form the upper tier. Then on the lower tier each universal criterion is altered in a manner that adapts it to particular cultural settings. The scheme is traced through the steps of: #op1#cp identifying universal standards and their supporting rationales #op2#cp proposing a process for generating culture-specific criteria under each universal standard, and #op3#cp suggesting aproaches to evaluation that utilize the criteria.     

Universal and culturally specific criteria for evaluating early-childhood-education programs

An issue of international concern in early-childhood education is the question: To what extent should criteria or standards for evaluating the success of early-childhood education-programs be universal #opapplicable to programs any place at any time#cp and to what extent should criteria be culture specific #opsuitable for some societies but not for others#cp? This paper suggests an answer by means of a scheme for categorizing criteria on two tiers. Universal criteria form the upper tier. Then on the lower tier each universal criterion is altered in a manner that adapts it to particular cultural settings. The scheme is traced through the steps of: #op1#cp identifying universal standards and their supporting rationales #op2#cp proposing a process for generating culture-specific criteria under each universal standard, and #op3#cp suggesting aproaches to evaluation that utilize the criteria.     

Reporting the study populations of clinical trials. Clear transmission or static on the line?

In contrast to attempts that have been made to measure the clarity of reporting of the methods of clinical trials in journal articles, we report here an attempt to measure the accuracy of methods reporting. We focus in this article on eligibility criteria as a test case for the reporting of clinical trial methods. We examined the reporting of eligibility criteria in the protocol, methods paper (if applicable), journal article, and Clinical Alert for articles appearing in print between January 1988 and September 1994 for which a Clinical Alert had been issued. Eligibility criteria were further classified into five categories in order to examine the content of information loss, if any. On average, 82% of protocol eligibility criteria were reported in methods papers. Journal articles and Clinical Alerts fared somewhat worse: 63% of criteria were reported in journal articles, 19% in Clinical Alerts. In all three categories of medical communication, the reporting of criteria that defined the study disease tended to be complete; reporting of criteria relating to trial precision, patient safety, legal and ethical concerns, and administrative considerations, was not complete. We found that criteria for clinical trial eligibility are frequently under-reported in medical communications. Moreover, some of the criteria omitted are of considerable clinical importance. We suggest that in the design phase of clinical trials, proposed eligibility criteria be scrutinized closely. Those criteria that survive this scrutiny and that have clinical import must be reported upon fully and accurately when communicating trial results.     

Comparison of the GLIM,ESPEN and ICD-10 Criteria to Diagnose Malnutrition and Predict 30-Day Outcomes: An Observational Study in an Oncology Population

The Global Leadership Initiative on Malnutrition (GLIM) criteria are consensus criteria for the diagnosis of malnutrition. This study aimed to investigate and compare the prevalence of malnutrition using the GLIM, European Society for Clinical Nutrition and Metabolism (ESPEN) and International Statistical Classification of Diseases version 10 (ICD-10) criteria; compare the level of agreement between these criteria; and identify the predictive validity of each set of criteria with respect to 30-day outcomes in a large cancer cohort. GLIM, ESPEN and ICD-10 were applied to determine the prevalence of malnutrition in 2794 participants from two cancer malnutrition point prevalence studies. Agreement between the criteria was analysed using the Cohen’s Kappa statistic. Binary logistic regression models were used to determine the ability of each set of criteria to predict 30-day mortality and unplanned admission or readmission. GLIM, ESPEN and ICD-10 criteria identified 23.0%, 5.5% and 12.6% of the cohort as malnourished, respectively. Slight-to-fair agreement was reported between the criteria. All three criteria were predictive of mortality, but only the GLIM and ICD-10 criteria were predictive of unplanned admission or readmission at 30 days. The GLIM criteria identified the highest prevalence of malnutrition and had the greatest predictive ability for mortality and unplanned admission or readmission in an oncology population.     

Nursing facility and home and community based service need criteria in the United States

Over the past two decades states have expanded the delivery of long term care from institutions to the home and community. Although state Medicaid need criteria for the home and community based services (HCBS) waiver program must be equivalent to those for nursing facility (NF) criteria, other screening procedures for these services are not specified. This study examined variations in need criteria, methods for determining need, and assessment forms for NF and HCBS across the states, and identified whether these procedures were more stringent for HCBS than for NFs. The NF minimum need criteria was most often (31 states) based on a combination of nursing, medical, functional, or other psychosocial criteria, 10 states used nursing criteria, and 10 states used limitations in functional activities criteria. The method used for determining need for NF was based on explicit criteria in 25 states, point systems in seven states, and 19 states used guidelines that allowed for judgment by those conducting the assessment. The average length of a NF assessment form was six and one-half pages, which was four pages shorter than the average HCBS form. Within some states the HCBS waivers have higher need criteria, more comprehensive need determination, and longer assessment forms than NFs. Wide variability in screening procedures creates potential inequities to LTC services across the states. Within states, more restrictive screening procedures for HCBS than for NF may limit access to community based long term care.     

Depressive states and health problems in caregivers of the disabled elderly at home

This study investigated the prevalence of depression and health problems in caregivers for the disabled elderly at home, and identified factors associated with the risk of depression. Four hundred thirty-four caregivers for disabled elderly persons in a suburban city were surveyed by in-home interviews. Two hundred ten non-caregivers were also interviewed as an age and gender-matched control group. Overall, 16.8% of caregivers met the DSM-III-R criteria for major depression and 10.6% met the criteria for depressive disorders not otherwise specified, for a total of 27.4% meeting the criteria for affective disorders, while 8.6% of controls met the criteria for depressive disorders not otherwise specified. The prevalence of major depression in caregivers was associated with mental problems and ADL limitations of the elderly. Moreover, non-cooperation by other family members or relatives contributed to an increase in the prevalence of depression. Caregivers who met the criteria for major depression had a higher frequency and longer duration of upper respiratory infections than other caregivers or controls, and showed greater fatigue than the other caregivers or controls. Approximately 90% of caregivers who met the criteria for major depression had also insomnia. Overall, it was shown that caregivers who met the criteria for major depressin had not only emotional distress but also higher morbidity.     

Enhancing credibility of chemical safety studies: emerging consensus on key assessment criteria

Objectives

We examined the extent to which consensus exists on the criteria that should be used for assessing the credibility of a scientific work, regardless of its funding source, and explored how these criteria might be implemented.

Data sources

Three publications, all presented at a session of the 2009 annual meeting of the Society for Risk Analysis, have proposed a range of criteria for evaluating the credibility of scientific studies. At least two other similar sets of criteria have recently been proposed elsewhere.

Data extraction/synthesis

In this article we review these criteria, highlight the commonalities among them, and integrate them into a list of 10 criteria. We also discuss issues inherent in any attempt to implement the criteria systematically.

Conclusions

Recommendations by many scientists and policy experts converge on a finite list of criteria for assessing the credibility of a scientific study without regard to funding source. These criteria should be formalized through a consensus process or a governmental initiative that includes discussion and pilot application of a system for reproducibly implementing them. Formal establishment of such a system should enable the debate regarding chemical studies to move beyond funding issues and focus on scientific merit.     

妊娠期糖尿病诊断标准的探讨

目的:探讨适合我国的妊娠期糖尿病诊断标准。方法:选择2OO8年1～12月在西丽人民医院确诊的妊娠期糖尿病(GDM)患者43例,妊娠期糖耐量受损患者(GIGT)57例,用美国糖尿病协会(ADA)、世界卫生组织(WHO)和美国国家糖尿病数据组(NDDG)的诊断标准进行重新诊断,同时分析比较不同诊断标准的母儿结局。结果:《妇产科学》第6版的诊断标准与ADA诊断标准比较,GDM检出率无统计学意义(P0.05);与WHO诊断标准和NDDG诊断标准比较,GDM检出率有统计学意义(P0.05);与ADA、WHO诊断标准检出GDM的母儿结局比较无统计学意义(P0.05);与NDDG诊断标准比较,两组检出GDM的剖宫产、巨大儿、妊高征、羊水过多的发生率无统计学意义(P0.05),但被NDDG诊断标准排除的GDM患者中,包括1例因GDM死胎患者,2例GDM发生胎儿窘迫患者。结论:采用ADA诊断标作为GDM的诊断标准是可行的。     

Prevalence of anorexia nervosa and bulimia in three student populations

A confidential questionnaire, covering the DSM-III criteria for anorexia nervosa and bulimia, was administered to three samples of students, totalling 1060 individuals, at two colleges and a secondary school. Although none of the male respondents met DSM-III criteria for either disorder, 1.0% to 4.2% of women met DSM-III criteria for a history of anorexia nervosa (with or without a history of bulimia), and an additional 6.5% to 18.6% met DSM-III criteria for a history of bulimia alone. Even when allowance is made for the number of nonrespondents, possible falsepositive questionnaire responses, and the limitations of the DSM-III criteria themselves, the prevalence rates appear substantial. Taking into account the mean ages of various samples, our results agree closely with two previous studies that each examined a single sample of students. These results augment the growing evidence that the eating disorders represent a serious public health problem.     

Monitoring Quality of Nursing Care

The first phase of a cooperative project to develop and pilot-test an improved system for monitoring the quality of nursing care is described. Evaluation criteria from existing methodologies were grouped in a comprehensive framework of nursing objectives and subobjectives, and both the framework and the criteria developed were tested statistically. The master criteria list was placed in a computer file, from which criteria subsets are systematically selected for actual quality monitoring. The methodology has been used in two pilot hospitals; in the second phase of the project, now under way, the system is being implemented in a wider sample of hospitals to further test the validity of the conceptual framework and the reliability of individual criteria.     

A statistically based method for identifying hospital classification criteria

The development of valid classification criteria for U.S. hospitals. A number of bills recently introduced in the U.S. Congress call for the linkage of classification criteria to cost limits for hospitals. Such proposals have not indicated how the classification criteria should be validated or tested.A research project was therefore undertaken to determine whether 87 large community hospitals could be classified into interpretable and reproducible homogenous groups. By means of an automatic interaction detector (AID), a set of unique classification criteria were identified. These included residency and internship education programs, medical school affiliation, renal dialysis, and organ bank facilities. Application of the criteria to 1970 and 1971 data for the 87 hospitals resulted in five reproducible and stable groups of hospitals. The criteria were validated by several tests involving different types of cost comparisons and ratios.The research results indicate that an AID-based classification structure is a feasible model for grouping or classifying large hospitals for comparative purposes. Only a small number of variables are necessary to classify large hospitals, and the criteria do not need to be overly complex. Many of the variables traditionally used may be omitted.