Estimates of hospital and physician costs of epilepsy in the United States for 1995 comparing the provider -based survey method and a patient -based medical charts and billing method

This investigation compares two different methodologies for calculating the national cost of epilepsy: provider-based survey method (PBSM) and the patient-based medical charts and billing method (PBMC&BM). The PBSM uses the National Hospital Discharge Survey (NHDS), the National Hospital Ambulatory Medical Care Survey (NHAMCS) and the National Ambulatory Medical Care Survey (NAMCS) as the sources of utilization. The PBMC&BM uses patient data, charts and billings, to determine utilization rates for specific components of hospital, physician and drug prescriptions. ^ The 1995 hospital and physician cost of epilepsy is estimated to be $722 million using the PBSM and $1,058 million using the PBMC&BM. The difference of $336 million results from $136 million difference in utilization and $200 million difference in unit cost. ^ Utilization. The utilization difference of $136 million is composed of an inpatient variation of $129 million, $100 million hospital and $29 million physician, and an ambulatory variation of $7 million. The $100 million hospital variance is attributed to inclusion of febrile seizures in the PBSM, $−79 million, and the exclusion of admissions attributed to epilepsy, $179 million. The former suggests that the diagnostic codes used in the NHDS may not properly match the current definition of epilepsy as used in the PBMC&BM. The latter suggests NHDS errors in the attribution of an admission to the principal diagnosis. ^ The $29 million variance in inpatient physician utilization is the result of different per-day-of-care physician visit rates, 1.3 for the PBMC&BM versus 1.0 for the PBSM. The absence of visit frequency measures in the NHDS affects the internal validity of the PBSM estimate and requires the investigator to make conservative assumptions. ^ The remaining ambulatory resource utilization variance is $7 million. Of this amount, $22 million is the result of an underestimate of ancillaries in the NHAMCS and NAMCS extrapolations using the patient visit weight. ^ Unit cost. The resource cost variation is $200 million, inpatient is $22 million and ambulatory is $178 million. The inpatient variation of $22 million is composed of $19 million in hospital per day rates, due to a higher cost per day in the PBMC&BM, and $3 million in physician visit rates, due to a higher cost per visit in the PBMC&BM. ^ The ambulatory cost variance is $178 million, composed of higher per-physician-visit costs of $97 million and higher per-ancillary costs of $81 million. Both are attributed to the PBMC&BM's precise identification of resource utilization that permits accurate valuation. ^ Conclusion. Both methods have specific limitations. The PBSM strengths are its sample designs that lead to nationally representative estimates and permit statistical point and confidence interval estimation for the nation for certain variables under investigation. However, the findings of this investigation suggest the internal validity of the estimates derived is questionable and important additional information required to precisely estimate the cost of an illness is absent. ^ The PBMC&BM is a superior method in identifying resources utilized in the physician encounter with the patient permitting more accurate valuation. However, the PBMC&BM does not have the statistical reliability of the PBSM; it relies on synthesized national prevalence estimates to extrapolate a national cost estimate. While precision is important, the ability to generalize to the nation may be limited due to the small number of patients that are followed. ^

HEALTH CARE COST INCREASES IN METROPOLITAN AREAS

The research project is an extension of the economic theory to the health care field and health care research projects evaluating the influence of demand and supply variables upon medical care inflation. The research tests a model linking the demographic and socioeconomic characteristics of the population, its community case mix, and technology, the prices of goods and services other than medical care, the way its medical services are delivered and the health care resources available to its population to different utilization patterns which, consequently, lead to variations in health care prices among metropolitan areas. The research considers the relationship of changes in community characteristics and resources and medical care inflation.^ The rapidly increasing costs of medical care have been of great concern to the general public, medical profession, and political bodies. Research and analysis of the main factors responsible for the rate of increase of medical care prices is necessary in order to devise appropriate solutions to cope with the problem. An understanding of the community characteristics and resources-medical care costs relationships in the metropolitan areas potentially offers guidance in individual plan and national policy development.^ The research considers 145 factors measuring community milieu (demographic, social, educational, economic, illness level, prices of goods and services other than medical care, hospital supply, physicians resources and techological factors). Through bivariate correlation analysis, the number of variables was reduced to a set of 1 to 4 variables for each cost equation. Two approaches were identified to track inflation in the health care industry. One approach measures costs of production which accounts for price and volume increases. The other approach measures price increases. One general and four specific measures were developed to represent each of the major approaches. The general measure considers the increase on medical care prices as a whole and the specific measures deal with hospital costs and physician's fees. The relationships among changes in community characteristics and resources and health care inflation were analyzed using bivariate correlation and regression analysis methods. It has been concluded that changes in community characteristics and resources are predictive of hospital costs and physician's fees inflation, but are not predictive of increases in medical care prices. These findings provide guidance in the formulation of public policy which could alter the trend of medical care inflation and in the allocation of limited Federal funds.^

Analysis of the mechanisms that maintain coordinate production of $\alpha$- and $\beta$-tubulin in mammalian cells

Alpha and beta tubulin are essential proteins in all eukaryotic cells. To study how cells maintain coordinate levels of these two interacting proteins, we have used PCR to add a 9 amino acid epitope from influenza hemagglutinin protein onto the carboxyl terminus of $\alpha$1 and $\beta$1-tubulin. The chimeric tubulin genes (HA$\alpha$1 and HA$\beta$1) were transfected into CHO cells and cell lines that stably express each gene were selected. Cells transfected with HA-tubulin do not exhibit any gross changes in growth or morphology. Immunofluorescence analysis demonstrated that HA-tubulins incorporate into both cytoplasmic and spindle microtubules. A quantitative biochemical assay was used to show that HA-tubulins incorporate into microtubules to a normal extent and do not alter the steady state distribution of endogenous tubulin between monomer and polymer pools. Two-dimensional gel analysis of pulse-labeled cells indicated that when HA$\beta$1-tubulin is expressed at high levels, it slightly represses the synthesis of the endogenous $\beta$-tubulin but produces a small increase in the synthesis of $\alpha$-tubulin. Analysis of cells labeled to steady state showed that HA$\beta$1-tubulin accumulates to a similar level as the wild-type gene product, but together these polypeptides produce only a small increase in total tubulin content consistent with the increased synthesis of $\alpha$-tubulin. It thus appears that HA$\beta$1-tubulin successfully competes with endogenous $\beta$-tubulin for heterodimer formation and that free $\beta$-tubulin subunits (endogenous and HA$\beta$1) are selectively degraded to maintain coordinate amounts of $\alpha$- and $\beta$-tubulin. In addition, the increased synthesis of $\alpha$-tubulin suggested the existence of a mechanism to ensure coordinate synthesis of $\alpha$- and $\beta$-tubulin subunits. To analyze whether reciprocal changes in endogenous tubulin synthesis occur when $\alpha$-tubulin is overexpressed, stably transfected CHO cell lines were isolated in which HA$\alpha$1-tubulin represents 50% of the total $\alpha$-tubulin, and its relative abundance can be further increased to 85-90% by treatment with sodium butyrate. In contrast with results obtained using HA$\beta$1-tubulin, transfection of HA$\alpha$1-tubulin decreased the synthesis of endogenous $\alpha$-tubulin to 60% of normal with little or no change in $\beta$-tubulin synthesis. When the transfected cells were treated with sodium butyrate to further increase HA$\beta$1-tubulin production, a larger decrease in the synthesis of endogenous $\alpha$-tubulin (to 30% of normal) was observed. The repression on the synthesis of endogenous $\alpha$-tubulin polypeptide was found to be directly proportional to the expression of HA$\alpha$1-tubulin indicating the existence of an autoregulatory loop, where $\alpha$-tubulin inhibits its own synthesis. To determine whether overproduction of HA$\alpha$1-tubulin affected the transcription, message stability or translation of endogenous $\alpha$-tubulin, the steady state levels of $\alpha$-tubulin mRNA were analyzed by ribonuclease protection assays. The results showed that the steady state level of $\alpha$-tubulin mRNA is not affected by the overexpression of HA$\alpha$1-tubulin, indicating that the repression is translational. The results are compatible with a model in which $\beta$-tubulin synthesis is largely unperturbed by overexpression of other tubulin subunits, and excess $\beta$-tubulin subunits are rapidly degraded to maintain coordinate $\alpha$- and $\beta$-tubulin levels at steady state. In contrast, free $\alpha$-tubulin represses its own synthesis at the translational level, suggesting that its level of production may be controlled by the amount of $\beta$-tubulin available for heterodimer formation. ^

Comparison of medical care costs, utilization, and satisfaction of AIDS patients with and without home care

A sample of 157 AIDS patients 17 years of age or over were followed for six months from the date of hospital discharge to derive average total cost of medical care, utilization and satisfaction with care. Those referred for home care follow-up after discharge from the hospital were compared with those who did not receive home care.^ The average total cost of medical care for all patients was $34,984. Home care patient costs averaged \$29,614 while patients with no home care averaged $37,091. Private hospital patients had average costs of \$50,650 compared with $25,494 for public hospital patients. Hospital days for the six months period averaged 23.9 per patient for the no home care group and 18.5 days for home care group. Patient satisfaction with care was higher in the home care group than no home care group, with a mean score of 68.2 compared with 61.1.^ Other health services information indicated that 98% of the private hospital patients had insurance while only 2% of public hospital patients had coverage. The time between the initial date of diagnosis with AIDS and admission to the study was longer for private hospital patients, survival time over the study period was shorter, and the number of hospitalizations prior to entering the study was higher for private hospital patients. These results suggest that patients treated in the private hospital were sicker than public hospital patients, which may explain their higher average total cost. Statistical analyses showed that cost and utilization have no significant relationship with home care or no home care when controlling for indicators of the severity of illness and treatment in public or private hospital.^ In future studies, selecting a matched group of patients from the same hospital and following them for nine months to one year would be helpful in making a more realistic comparison of the cost effectiveness of home care. ^

AN EMPIRICAL ESTIMATION OF MEDICAL AND NON-MEDICAL INPUTS IN THE PRODUCTION OF CARDIO-RESPIRATORY PHYSICAL HEALTH STATUS

The purpose of this study was to examine, in the context of an economic model of health production, the relationship between inputs (health influencing activities) and fitness.^ Primary data were collected from 204 employees of a large insurance company at the time of their enrollment in an industrially-based health promotion program. The inputs of production included medical care use, exercise, smoking, drinking, eating, coronary disease history, and obesity. The variables of age, gender and education known to affect the production process were also examined. Two estimates of fitness were used; self-report and a physiologic estimate based on exercise treadmill performance. Ordinary least squares and two-stage least squares regression analyses were used to estimate the fitness production functions.^ In the production of self-reported fitness status the coefficients for the exercise, smoking, eating, and drinking production inputs, and the control variable of gender were statistically significant and possessed theoretically correct signs. In the production of physiologic fitness exercise, smoking and gender were statistically significant. Exercise and gender were theoretically consistent while smoking was not. Results are compared with previous analyses of health production. ^