South Florida Program on Aging and Health. Assessing the prevalence of Alzheimer's disease in three ethnic groups.

The South Florida Program on Aging and Health was initiated in 1992 with the aim to assess physical and mental health of the elderly in Dade County and provide a basis for public health policy. This report describes the methodology applied in the study and preliminary screening results in a probability sample of 2,400 African American, Cuban American and white non-Hispanic American elderly men and women. Of 2,013 participants screened by May 1995, 11.5% had cognitive impairment. An increase in prevalence from 4-7% to 25-36% with advancing age was found among men and women of each group, from the youngest (65-74) to the oldest (85+ years). Male and female prevalences were similar but vary by ethnic group and age.

A standards-based clinical information system for HIV/AIDS.

OBJECTIVE: To create a clinical data repository to interface the Veteran's Administration (VA) Decentralized Hospital Computer Program (DHCP) and a departmental clinical information system for the management of HIV patients. This system supports record-keeping, decision-making, reporting, and analysis. The database development was designed to overcome two impediments to successful implementations of clinical databases: (i) lack of a standard reference data model, and; (ii) lack of a universal standard for medical concept representation. BACKGROUND: Health Level Seven (HL7) is a standard protocol that specifies the implementation of interfaces between two computer applications (sender and receiver) from different vendors or sources of electronic data exchange in the health care environment. This eliminates or substantially reduces the custom interface programming and program maintenance that would otherwise be required. HL7 defines the data to be exchanged, the timing of the interchange, and the communication of errors to the application. The formats are generic in nature and must be configured to meet the needs of the two applications involved. The standard conceptually operates at the seventh level of the ISO model for Open Systems Interconnection (OSI). The OSI simply defines the data elements that are exchanged as abstract messages, and does not prescribe the exact bit stream of the messages that flow over the network. Lower level network software developed according to the OSI model may be used to encode and decode the actual bit stream. The OSI protocols are not universally implemented and, therefore, a set of encoding rules for defining the exact representation of a message must be specified. The VA has created an HL7 module to assist DHCP applications in exchanging health care information with other applications using the HL7 protocol. The DHCP HL7 module consists of a set of utility routines and files that provide a generic interface to the HL7 protocol for all DHCP applications. SETTING: The VA's DHCP core modules are in standard use at 169 hospitals, and the role of the VA system in health care delivery has been discussed elsewhere. This development was performed at the Miami VA Medical Center Special Immunology Unit, where a database was created for an HIV patient registry in 1987. Over 2,300 patient have been entered into a database that supports a problem-oriented summary of the patient's clinical record. The interface to the VA DHCP was designed and implemented to capture information from the patient treatment file, pharmacy, laboratory, radiology, and other modules. RESULTS: We obtained a suite of programs for implementing the HL7 encoding rules from Columbia-Presbyterian Medical Center in New York, written in ANSI C. This toolkit isolates our application programs from the details of the HL7 encoding rules, and allows them to deal with abstract messages and the programming level. While HL7 has become a standard for healthcare message exchange, SQL (Structured Query Language) is the standard for database definition, data manipulation, and query. The target database (Stitt F.W. The Problem-Oriented Medical Synopsis: a patient-centered clinical information system. Proc 17 SCAMC. 1993:88-93) provides clinical workstation functionality. Medical concepts are encoded using a preferred terminology derived from over 15 sources that include the Unified Medical Language System and SNOMed International ( Stitt F.W. The Problem-Oriented Medical Synopsis: coding, indexing, and classification sub-model. Proc 18 SCAMC, 1994: in press). The databases were modeled using the Information Engineering CASE tools, and were written using relational database utilities, including embedded SQL in C (ESQL/C). We linked ESQL/C programs to the HL7 toolkit to allow data to be inserted, deleted, or updated, under transaction control. A graphical format will be used to display the entity-rel

Using Markov processes to describe the prognosis of HIV-1 infection.

In 1989, Turner and colleagues proposed a new method for automated classification and prediction of outcomes for hospitalized patients with AIDS, based on severity of illness. The authors have confirmed this system, which includes three main stages and 20 substages, in a cohort of HIV-1-infected symptomatic patients admitted to the Miami Veteran's Affairs Medical Center (VAMC) since 1988. They propose a new model of Markov illness-and-death processes and use it to describe the disease progression of the patient cohort. The new Markov model also measures transitions between stages, including risk factors associated with the speed of transitions. Significant differences in survival experiences were found from the different disease stages. The estimated mean (median) survival times were: from stage 1, 21.0 (17.8) months; from stage 2, 10.5 (8.4) months; and from stage 3, 6.7 (4.7) months. In addition, age at HIV-1 diagnosis and homosexual behavior were significant prognostic factors for disease progression and survival. The results indicate that the combination of a severity-of-illness clinical staging system with Markov illness-and-death process modeling is particularly useful for the evaluation of prognostic factors influencing the course of HIV-1 disease progression.

The problem-oriented medical synopsis: coding, indexing, and classification sub-model.

A clinical information system consists of four major components: the clinical database, decision support, data analysis (including outcomes), and the development system. We have created such a system using generally available database methodology. The system is documented using a conceptual model, a physical model, and sub-models for individual components. A key sub-model of the clinical database, for record-keeping, has been defined for coding, indexing, and classification of the medical narrative typically encountered in medical records. We describe an approach to the development of the coding component that results in a hybrid system for recording information, locating indexed information, and summarizing it for analysis of outcomes. These are based on a primary term list--the problem glossary; SNOMed--the Systematized Nomenclature of Medicine (3rd. edition); and ICD-9-CM. The relationship with the UMLS is also discussed.

The Problem-Oriented Medical Synopsis: a patient-centered clinical information system.

A clinical information system consists of four major components: the clinical database, decision support, data analysis (including outcomes), and the development system. We have created such a system using generally available database methodology. The clinical database, for record-keeping, is called the Problem-Oriented Medical Synopsis, and is quite an old system, originating in 1966. We describe the suitability of a problem-oriented model of clinical records management to the relational model of database design, and describe our experience with the database as a departmental information system for patient care and outcomes research. Hybrid, or partially problem-oriented, databases represent an acceptable approach to clinical record-keeping.

Automated severity classification of AIDS hospitalizations.

To validate an automated AIDS severity-of-illness prognostic algorithm, 2,113 discharge summaries of HIV-infected patients were merged with the Problem-Oriented Medical Synopsis (POMS) and an HIV risk registry. The combination of a medically derived classification and staging algorithm with multivariate statistical techniques was used for automated severity-of-illness disease staging and prognostic assignment. The model correctly predicted the outcomes of 82% of all cases (death, survivorship) at discharge, and 66% of deaths.

Effect of dietary ascorbic acid on the incidence of spontaneous mammary tumors in RIII mice.

A study of the effect of different amounts of L-ascorbic acid (vitamin C), between 0.076% and 8.3%, contained in the food has been carried out with ten groups of RIII mice (seven ascorbic acid and three control groups), with 50 mice in each group. With an increase in the amount of ascorbic acid there is a highly significant decrease in the first-order rate constant for appearance of the first spontaneous mammary tumor after the lag time to detection by palpation. There is also an increase in the lag time. The mean body weight and mean food intake were not significantly different for the seven ascorbic acid groups. Striking differences were observed between the 0.076% ascorbic acid and the control groups (which synthesize the vitamin): smaller food intake, decreased lag time, and increased rate constant of appearance of the first mammary tumor. This comparison cannot be made experimentally for guinea pigs and primates because the control groups would develop scurvy.

Increasing dose of naproxen in rheumatoid arthritis: use with and without corticosteroids.

A group of 50 patients with rheumatoid arthritis (half of whom received prednisone for 12 weeks before and then during the study) participated in a double-blind trial evaluating the efficacy and safety of 3 dosages of naproxen (125, 250, and 500 mg b.i.d.). Increasing dosages of naproxen were associated with increasing levels of therapeutic response and increasing serum levels of naproxen with no evidence of toxicity. Corticosteroid patients did not exhibit the same pattern of increasing levels of efficacy. The study demonstrates a dosage-related increasing pattern of efficacy for naproxen up to 1,000 mg/day, a pattern not yet demonstrated for the other non-steroidal antinflammatory drugs.

Vigorous exercise in leisure time, coronary risk-factors, and resting electrocardiogram in middle-aged male civil servants.

During 1968 to 1970, approximately 17 000 middle-aged male executive grade civil service officers, all of them engaged in sedentary or very light work, recorded on a Monday morning their leisure time activities over the previous Friday and Saturday. In 1971 a sample of 509 of these men completed further questionnaires for medical, social, and smoking history; these men had a resting electrocardiogram, and height, weight, skinfold thickness, blood pressure, and plasma total cholesterol were measured. Vigorous exercise in leisure time had previously been reported by 125 (25%) of the men, and these as a group had significantly fewer electrocardiographic abnormalities (changes compatible with myocardial ischaemia, ectopic beats, and sinus tachycardia) than the men not reporting vigorous exercise (P less than 0-02). This difference remained when all men with any history suggestive of cardiovascular disease were excluded from the analysis. Blood pressure, plasma total cholesterol, and smoking habits were examined with respect both to vigorous exercise and to the electrocardiogram, but the only relation found was that electrocardiographic abnormality increased with increasing blood pressure. Even among men with higher pressures, however, those reporting vigorous exercise had fewer electrographic abnormalities than the others. The results provide further support for the association of habitual physical activity with coronary health.