Biomedical subjects

S D Horn

Publications and source records attributed to S D Horn.

12 recordsLinked to original sources

PubMed1979

The relationship between infant mortality rates and medical care and socio-economic variables, Chile 1960-1970.

Infant mortality rates (IMR) have traditionally been considered useful as health status indicators, and changes in these rates are thought to reflect changes in both medical care services and socio-economic circumstances. In order to explore this relationship of IMR with medical core and socio-economic factors in a developing country, Chilean health zone data for the decade 1960--1970 were used to construct 25 variables which were then classified into groups representing antenatal-obstetric services, acute and preventive medical services and socio-economic variables. In an analysis which involved developing a series of linear multiple regression equations for each year of the decade 1960--1970 with IMR as the dependent variable, the percentage of births with professional attention proved to be the stronger variable.

Child Health Services↗

PubMed1979

Validity of medical staff judgments in establishing quality assurance priorities.

The validation of a structured group judgment procedure to establish priorities for quality assurance activities was undertaken in six medical institutions in the United States. Validation focused on the extent to which health improvement could be documented by outcome-based projects focusing on priority topics. Predictive (criterion-related) validity was sought by analyzing five successively more stringent levels of evidence: 1) feasibility of implementing a quality assessment project within the topic areas selected by the prioity procedure; 2) accuracy of identifying health deficiencies or strengths; 3) verification of establishing correctable causes of health deficiencies; 4) capability of effecting significant improvement of health deficiencies; and 5) credibility of evidence that improvement achieved is directly attributable to corrective actions taken. Within the limits of generalizability, predictive validity was documented at every level of analysis. It is recommended that the structured group judgment process used in this study be more thoroughly evaluated and considered for quality assurance planning purposes.

Decision Making↗

PubMed1979

An analysis of case mix complexity using information theory and diagnostic related grouping.

Case mix complexity measurements are essential to determine health care efficiency and effectiveness. Measures of patient care processes and outcomes must be adjusted for case mix before valid comparisons can be made. Hospital reimbursement, particularly prospective reimbursement, must take into account differences in case mix. In addition, a key variable for hospital classification is case mix. There are, however, no widely accepted easily computed case mix measures. Information theory measures of case mix have been developed but their acceptance has been limited by a lack of verification of their basic assumption that concentration of disease is related to clinical complexity. We discuss the rationale underlying the mathematical computaton of information theory measures and demonstrate a statistically significant relationship between clinical measures of case mix complexity and information theory measures of case mix complexity.

Costs and Cost Analysis↗

PubMed1979

Hospital cost per case: analyses using a statewide data system.

In this paper, we establish relationships between hospital cost per case and the independent variables; case mix complexity, case mix severity, factor input prices, and hospital characteristics. Two hundred and sixteen thousand discharges from Maryland's acute general hospitals are grouped into 383 Diagnostic Related Groups which are used to compute an information theoretic measure of case mix complexity. Multiple linear regression equations are developed which predict up to 88% of the variance of between-hospital cost per case. The most highly significant predictors of cost per case are complexity, patient age, proportion of high risk patients, average length of stay, and nonphysician salary levels. Two distinct groups of hospitals, metropolitan and rural, are defined and models are developed for each. We discuss the implications of these findings for the identification and regulation of unexpectedly high cost hospitals and for prospective cost per case reimbursement.

Analysis of Variance↗

PubMed1979

Variations in utilization of health services by children.

In this longitudinal study in two prepaid group practices, many more children stayed at the same level of use of services over a six- to ten-year period than would be expected if use of services had distributed randomly. Overall, about 13% remained consistently in the highest third of the distribution of use, and another 13% remained consistently in the middle or lowest third. If use of services had distributed randomly, 4% and 7%, respectively, would have been in these groups. Conversely, many fewer children (25%) showed fluctuating patterns of use over time than would be expected by chance alone (37%). Although the reasons for this phenomenon are unknown (and may be multiple), the findings have implications both for clinical care and for development of policy regarding the organization and financing of health services for children.

Adolescent↗

PubMed1978

Selection of regression models for health care data.

We discuss several linear and nonlinear regression models and their appropriateness in modeling a set of data from a cohort study of the use of medical services in a prepaid medical plan. Although computational considerations once forced researchers to use linear models almost exclusively, modern computer hardware and efficient algorithms have made it possible to use nonlinear models almost as easily as linear ones. Thus, in choosing a regression model, a researcher should give strong consideration to how well the model reflects (presumed) intrinsic properties of the phenomena under study, even if the consideration leads to the choice of a nonlinear model. Modern computer programs for nonlinear minimization should be employed to fit the model. The model should be judged on how well it describes the data and how reasonably it predicts the future.

Health Maintenance Organizations↗

PubMed1978

Priority setting in quality assurance: reliability of staff judgments in medical institutions.

A structured procedure using the judgments of a representative group of local providers for establishing priorities for quality assurance activity in diverse medical institutions was tested for reliability. Two independent matched teams of phy sicians, nurses, administrators, and other staff in eight separate medical facilities generated 320 topics which encompassed areas where quality assurance efforts would have either considerable or little impact in terms of improving health outcomes within reasonable costs. Concordance of judgment between teams in each facility was determined by analyzing the similarity of topics content, the agreement in scaling the health impact of similar topics generated by both teams independently, and the agreement by one team in scaling the health impact of topics generated by the other team. The findings revealed 44 per cent content agreement on topics independently generated, 93 per cent agreement on dichotomous scaling of similar topics, and 87 per cent agreement on five-point scaling of similar topics. Concordance of judgment by one team in scaling the other team's topics was highly significant (p less than .001). Preliminary analysis of topic content and scaling agreement among different facilities indicated low agreement both on the content areas and on the health impact of similar topics. It is concluded that the judgments of local providers in identifying cost-effective quality assurance priorities is highly relaible in the medical institutions studied.

Cost-Benefit Analysis↗

PubMed1978

Physicians and non-physician health practitioners: the characteristics of their practices and their relationships.

Six primary care practices which utilize both physician and non-physician practitioner types were studied to measure differences between practitioner types in the care of patients. By chart review 1,369 patient-practitioner encounters were examined. Physicians identified less symptoms and signs in their patients and prescribed less non-drug therapies than did non-physicians. Likewise, at follow-up visits, physicians tended to document less follow-up of these types of problems and therapies than non-physicians. When examining the interaction between practitioners, the highest rates of follow-up of all types of problems and therapies were found when the same practitioner saw the patient at two successive visits to the same clinic. When a physician saw a patient following a previous visit to a nurse practitioner, there was a significant drop-off in the follow-up rate of problems and therapies. However, when a nurse practitioner saw the patient following a previous visit to a physician, the drop-off in follow-up rates was not as striking. These findings indicate that the skills of physician and nonphysician practitioners are potentially complementary. However, this potential is not fully exploited, particularly by physicians.

Diagnosis↗

PubMed1977

An interpretation of implicit judgments in chart review.

The effects of methods that are commonly employed to summarize implicit judgments about quality-of-care assessments, based on medical records, are examined. A sample of 250 medical records, from three outpatient clinics in a municipal hospital, was studied. Two, or three, reviewers judged the quality of both the process of care and the outcome of care, as reflected in each medical record; the reviewers were medical school faculty members. Thirty-seven combinations of the data were used to summarize the judgments made on each medical record. These combinations resulted in significant differences in interpretation within each clinic, but there were only insignificant differences in interpretation across the three clinics. Hence, the use of a single method to summarize data may distort the conclusions. These results demonstrate that data often should be summarized by several methods and that measures of association should be used to supplement tests of significance so as to develop a comprehensive understanding of a set of data.

Factor Analysis, Statistical↗

PubMed1977

Goodness-of-fit tests for discrete data: a review and an application to a health impairment scale.

We review the advantages and disadvantages of several goodness-of-fit tests which may be used with discrete data: the multinomial test, the likelihood ratio test, the X2 test, the two-stage X2 test and the discrete Kolmogorov-Smirnov test. Although the X2 test is the best known and most widely used of these tests, its use with small sample sizes is controversial. If one has data which fall into ordered categories, then the discrete Kolmogorov-Smirnov test is an exact test which uses the information from the ordering and can be used for small sample sizes. We illustrate these points with an example of several analyses of health impairment data.

Diabetes Mellitus↗

PubMed1976

Continuity and coordination in primary care: their achievement and utility.

Coordination is a hallmark of primary care. Efforts to improve primary care services should involve assessment of the extent to which coordination is achieved. Our study in three adult and three pediatric clinics demonstrates that existing information concerning patients' problems, therapies, tests, and referrals is often not recognized by primary care practitioners. Recognition of these types of information is better when the practitioner who provides follow-up care is the same from one visit to the next. Information about visits which were anticipated by the practitioner, and particularly the content of these visits, is often neglected. The largest deficit, however, is in recognition of both the occurrence and content of visits unanticipated by the primary care practitioner. Greater efforts to achieve better coordination of care, by improving either continuity of practitioner, communication among practitioners, or the information system, are required before this essential element of primary care becomes a reality.

Adult↗

PubMed1976

Information factors affecting problem follow-up in ambulatory care.

The influence of information factors on the follow-up of patient problems was studied in six ambulatory clinics providing primary patient care. By means of chart review, the encounter notes were examined for two consecutive visits to the same clinic to determine problems identified at the first visit and detect evidence of follow-up of these problems at the second visit. In those clinics using a problem list, at the front of the chart, those problems on the problem list had a higher follow-up rate than those not on the list particularly at longer intervals between patient visits. An encounter note written in the problem-oriented format did not enhance follow-up. Since information factors as well as clinical factors affect the follow-up of patient problems these factors must be carefully considered when designing information systems to serve ambulatory care.

Adult↗