Approximate cross-validatory predictive checks in disease mapping models.

When fitting complex hierarchical disease mapping models, it can be important to identify regions that diverge from the assumed model. Since full leave-one-out cross-validatory assessment is extremely time-consuming when using Markov chain Monte Carlo (MCMC) estimation methods, Stern and Cressie consider an importance sampling approximation. We show that this can be improved upon through replication of both random effects and data. Our approach is simple to apply, entirely generic, and may aid the criticism of any Bayesian hierarchical model.

A Bayesian hierarchical approach to comparative audit for carotid surgery.

OBJECTIVES: the aim of this study was to illustrate how a Bayesian hierarchical modelling approach can aid the reliable comparison of outcome rates between surgeons. DESIGN: retrospective analysis of prospective and retrospective data. MATERIALS: binary outcome data (death/stroke within 30 days), together with information on 15 possible risk factors specific for CEA were available on 836 CEAs performed by four vascular surgeons from 1992-99. The median patient age was 68 (range 38-86) years and 60% were men. METHODS: the model was developed using the WinBUGS software. After adjusting for patient-level risk factors, a cross-validatory approach was adopted to identify "divergent" performance. A ranking exercise was also carried out. RESULTS: the overall observed 30-day stroke/death rate was 3.9% (33/836). The model found diabetes, stroke and heart disease to be significant risk factors. There was no significant difference between the predicted and observed outcome rates for any surgeon (Bayesian p -value>0.05). Each surgeon had a median rank of 3 with associated 95% CI 1.0-5.0, despite the variability of observed stroke/death rate from 2.9-4.4%. After risk adjustment, there was very little residual between-surgeon variability in outcome rate. CONCLUSIONS: Bayesian hierarchical models can help to accurately quantify the uncertainty associated with surgeons' performance and rank.

Supply, distribution, and capacity of optometrists in Indiana.

BACKGROUND: The Indiana Optometric Association and the Indiana Health Care Professional Development Commission identified a need to collect and analyze data on the health professions workforce for formulating goals and strategies to accommodate demands for health care services in Indiana. This study looks at the supply, distribution, and services of optometrists practicing in Indiana. METHODS: Data compiled by the Indiana State Department of Health, Indiana Health Care Development Commission, and the Project HOPE Center for Health Affairs were analyzed with the results of a survey of practitioner members of the Indiana Optometric Association. Supply, distribution, services, provider-to-population ratios, per capita demand, and optometric productivity were used to evaluate the current and future capacity of Indiana optometrists to the year 2010. RESULTS: An estimated 893 optometrists practiced in 86 of 92 counties and comprised 77% of the state's licensed eye and vision care workforce in 1995. Optometric workforce capacity appeared to be related to county population, but unrelated to the urban/rural classification or the per-capita income of Indiana counties. Contact lenses, disease, geriatrics, and pediatrics were the most prevalent areas of practice specialty. CONCLUSIONS: Optometrist capacity in Indiana is sufficient at both the state and county levels, and optometric services are appropriately distributed such that patient access to optometric care is geographically unburdened. Estimates regarding supply are elastic, depending on the assumptions applied.

Hypertension and the eye: applications of the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure.

BACKGROUND: High blood pressure is a major risk factor for coronary artery disease, kidney disease, and stroke. More people are aware of treating and controlling their blood pressure, but overall control rates are low and the incidence of hypertension-related morbidity and mortality remains high. METHODS: The National Heart, Lung, and Blood Institute released The Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI) as the most recent national guideline to hypertension control for primary care clinicians. RESULTS: JNC VI identifies 10 hypertension-related public health challenges: (1) prevent the rise of blood pressure; (2) decrease prevalence of hypertension; (3) increase awareness and detection of hypertension; (4) improve control of hypertension; (5) reduce cardiovascular risks; (6) increase recognition of importance of isolated systolic hypertension; (7) improve recognition of importance of high-normal blood pressure; (8) reduce ethnic, socioeconomic, and regional variations; (9) improve treatment; and (10) enhance community programs. CONCLUSIONS: The eye is a target organ and retinopathy is a frequent complication--as well as a prognostic indicator--of sustained hypertension. As part of a multidisciplinary team approach, the optometrist assumes a significant role in the prevention, detection, evaluation, and treatment of high blood pressure and its associated morbidities.

Reliability of league tables of in vitro fertilisation clinics: retrospective analysis of live birth rates.

OBJECTIVE: To determine to what extent institutions carrying out in vitro fertilisation can reasonably be ranked according to their live birth rates. DESIGN: Retrospective analysis of prospectively collected data on live birth rate after in vitro fertilisation. SETTING: 52 clinics in the United Kingdom carrying out in vitro fertilisation over the period April 1994 to March 1995. MAIN OUTCOME MEASURE: Estimated adjusted live birth rate for each clinic; their rank and its associated uncertainty. RESULTS: There were substantial and significant differences between the live birth rates of the clinics. There was great uncertainty, however, concerning the true ranks, particularly for the smaller clinics. Only one clinic could be confidently ranked in the bottom quarter according to this measure of performance. Many centres had substantial changes in rank between years, even though their live birth rate did not change significantly. CONCLUSIONS: Even when there are substantial differences between institutions, ranks are extremely unreliable statistical summaries of performance and change in performance, particularly for smaller institutions. Any performance indicator should always be associated with a measure of sampling variability.

Optometric manpower in the Commonwealth of Puerto Rico: estimates and projections, 1982-2025.

BACKGROUND: The 1982 study investigated the potential impact of the IAUPR School of Optometry on the adequacy of supply of optometrists in Puerto Rico for the years of 1980-2000. This article is designed to: (1) update the 1982 study; (2) appraise the accuracy of the 1982 projections; (3) re-evaluate the status of optometric manpower in Puerto Rico through the year 2025; and (4) provide the School of Optometry with information necessary to make informed judgments about future enrollments. METHODS: Estimates of supply are based on data from the Colegio de Optometras de Puerto Rico, the Sección de Oftalmología de la Asociación Médica de Puerto Rico, and the enrollment and graduation registries from the School of Optometry. Requirements are based on estimates of annual effective demand, provider-to-population ratios, per capita demand, and optometric productivity. RESULTS: Optometrists comprised 52.2% of Puerto Rico's actively practicing vision care manpower in 1995, with a mean optometrist-to-population ratio of 8.2 per 100,000. The number ranged from 28 in Mayagüez to 107 in San Juan. Under different assumptions regarding supply, productivity, and demand, surpluses and deficits are estimated and projected for the years 1995 to 2025. CONCLUSIONS: Depending on the assumptions used, an undersupply or an oversupply of optometrists may be found in Puerto Rico, currently and in the future. Projections of supply and demand predict a considerable range--from a surplus of 961 optometrists to a deficit of 2,085 optometrists in the year 2025.

Rationing the public's health and the optometric agenda.

BACKGROUND: Universal access to health care at an affordable price is a major issue on the current agenda of the nation's legislative, corporate and health care decision makers. METHODS: The current literature and prevailing ideologies on health service rationing and health care reform were reviewed and evaluated in the context of optometric practice. RESULTS AND CONCLUSION: The socio-political nature of the decision making process may lead to recommendations for reforms and market interventions that contravene the agenda of health care providers. To maintain quality of care and contain costs, and as a basis for allocation, judgments must be made about the value of specific services. Some services may be rationed according to the ratio of benefit to cost and their perceived net value to society. If rationing prevails, optometric services will be included in the process of prioritization and allocation.

The optometric educators' role in public health issues.

The optometric educator has a very important role in the development, analysis, interpretation, and promotion of public health issues. Because public health provides the framework for making rational decisions about the complexities of health care, the optometric educator has a high-order responsibility to educate students in the principles, concepts, and practice of public health. As both a creator and a deliverer of knowledge, the optometric educator also must ensure that the outcomes of his scientific inquiry are translated into relevant health policy and used effectively and efficiently for the benefit of all society. Advancement of the public health philosophy within the venue of optometric education should be the responsibility of all faculty, not just those members of the faculty who have direct responsibility for the public health curriculum.

Epidemiology of tumors affecting the visual system.

Cancer is a leading cause of morbidity and the second leading cause of mortality in the United States. The eye and adnexa are potential foci of neoplastic disease, either as primary sites or as sites of metastatic carcinoma. The most frequent anatomical site of ocular cancer is the eye, followed by the orbit, the conjunctiva, and the lacrimal gland. The average annual age-adjusted incidence of ocular cancer varies between 0.6 per 100,000 and 0.9 per 100,000 for the male population and between 0.5 per 100,000 and 0.8 per 100,000 for the female population. The distribution of eye cancer risk by age is bimodal, with peaks occurring during early childhood and again during adulthood. Retinoblastoma is the most common ocular malignancy in children, and uveal melanoma is the most common ocular malignancy in adults.

Disposable vs. non-disposable contact lenses-the relative risk of ocular infection.

The wearing of contact lenses is not without some risk. When prescribing contact lenses, several decisions must be made regarding the type of lens; for example, daily wear vs. extended wear and disposable or frequent replacement lenses vs. non-disposable or traditional (reusable) lenses. Often the decisions are based on issues of comfort, cost and/or the ability to fit the patient with one type or another. Consideration of a possible increase in the risk of ocular infection from contact lens wear is not necessarily a variable in the selection process, but maybe it should be. From the aspect of provider liability and as a public health issue, this paper will attempt to explore the relative risk of ocular infection associated with the wearing of disposable and traditional contact lenses.

Legislation, litigation, health policy and optometry.

Significant changes in health policy have occurred during the past 25 years. Directed primarily by congressional legislation and judicial opinion, many of these changes have resulted from efforts to control costs, improve quality and increase access. Optometric parity, reimbursement reform, freedom of choice, mandated benefits, commercial speech, self-insurance, competition and peer review are some of the issues that surround many of the more recent attempts at change in the health care market. Optometry has been and will continue to be affected by changes in health policy, especially with regard to issues of cost, quality and access.

Assurance of quality vision care in alternative health care delivery systems.

The continuing evolution of competitive arrangements in the marketing and delivery of health care services can have an adverse effect upon the quality of care. Traditional modes of health care delivery are being replaced by the more competitive alternative delivery and managed care systems. Practitioners, consumers, administrators and legislators are finding it increasingly difficult to balance the various issues that surround the desire for quality and the necessity of cost containment. Optometry must be able to establish its own standards and methods of evaluation for the assurance of quality eye care within the alternative delivery and managed care systems.

Racial differences in the presentation of chronic open-angle glaucoma.

Glaucoma is the third leading cause of blindness in the United States. A review of the literature suggests that blacks biologically are at greater risk for higher intraocular pressure, open-angle glaucoma and glaucoma-induced blindness. Although the incidence of blindness from all causes is reported to be about three times higher for nonwhites in comparison to whites, the risk of blindness from glaucoma in blacks is eight times that of whites. As the most prevalent type of glaucoma in the general population, chronic open-angle glaucoma occurs in the black population more often, at an earlier age, with greater severity, and with more damaging results.

Economic and professional aspects of disease prevention and health promotion.

The prevention of disease and the promotion of health, along with cost containment, have become major priorities in the planning for and the delivery of health care services. As the second most prevalent chronic health problem in the United States, vision disorders create a serious health and economic threat to society and, therefore, they should be considered as a prime target for inclusion in programs of disease prevention and health promotion. In recognition of the role and scope of the third largest independent health care profession and in consideration of its cost efficient delivery of eye and vision care services, optometry must become a more active participant in the development and implementation of strategies and programs for improving, maintaining and protecting the visual health of society.

Dental management of a patient with glycogen storage disease type I.

Patients with glycogen storage disease type I (GSD I) have varied medical problems, including a bleeding diathesis characterized by a prolonged bleeding time. A case of a patient with GSD I having a history of medical problems, some of which were related to oral and dental bleeding, was presented. The patient was cariesfree and had generalized moderate to severe periodontal breakdown. A treatment regimen in a hospital setting, using cryoprecipitate and aminocaproic acid, permitted dental care and control of oral bleeding and associated complications.

Report of the Graduate Medical Education National Advisory Committee to the secretary.

The Graduate Medical Education National Advisory Committee (GMENAC) was charged with the task of advising the Secretary of the Department of Health and Human Services on overall strategies on the present and future supply and requirements of physicians by specialty and geographic location. In September of 1980, GMENAC submitted its final report to the Secretary. Included in this report are policy directives that were issued in the form of recommendations; several of these recommendations are directed specifically at the independent non-physician health care professions. The potential impact of these recommendations upon the profession of optometry is monumental; and, the authority of GMENAC to issue directives regarding the supply of optometrists and the future requirements of optometric manpower must be challenged.

The optometrist's role in public health.

The scope of the optometric profession, and its relationship to the total health care system, is in a state of constant change; many of the changes are influenced by or impact upon that area of health care that is referred to as public health. Very basically, public health is "people's health" --a concern for the health and well-being of groups of people. It emphasizes the role of health care practitioners in the delivery of health care to the aggregate, as opposed to the individualized or private system of health care delivery. Fundamental to the overall philosophy of public health is the necessity to make comprehensive health care readily available and accessible to all segments of the population. Optometry must expand its efforts to recognize, evaluate and assume its role in the maintenance of the health and well-being of the public, both domestically and internationally.