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Biomedical subjects

A Dor

Publications and source records attributed to A Dor.

At least 19 recordsLinked to original sources
PubMed2001

Lack of health insurance and decline in overall health in late middle age.

BACKGROUND: The number of adults in their 50s and 60s in the United States who do not have health insurance is increasing. This group may be particularly vulnerable to the ill effects of being uninsured. METHODS: We conducted a prospective cohort study using files from the Health and Retirement Study, a national survey of adults who were 51 to 61 years old in 1992. We determined the risks of a major decline in overall health and of the development of new physical difficulties between 1992 and 1996 for participants who were continuously uninsured (uninsured in 1992 and in 1994), those who were intermittently uninsured (uninsured either in 1992 or in 1994), and those who were continuously insured. We used logistic regression to determine the independent effects of being uninsured on health outcomes after adjustment for base-line sociodemographic factors, preexisting medical conditions, and types of health-related behavior such as smoking and alcohol use. RESULTS: We analyzed data for 7577 participants. The 717 continuously uninsured participants and the 825 intermittently uninsured participants were more likely than the 6035 continuously insured participants to have a major decline in overall health between 1992 and 1996 (21.6 percent, 16.1 percent, and 8.3 percent of the three groups, respectively; P<0.001 for both comparisons). According to a multivariate analysis, the adjusted relative risk of a major decline in overall health was 1.63 (95 percent confidence interval, 1.26 to 2.08) for continuously uninsured participants and 1.41 (95 percent confidence interval, 1.11 to 1.78) for intermittently uninsured participants, as compared with continuously insured participants. A new difficulty in walking or climbing stairs was also more likely to develop in the continuously or intermittently uninsured participants than in the continuously insured participants (28.8 percent, 26.4 percent, and 17.1 percent of the three groups, respectively; P<0.001 for both comparisons). The adjusted relative risk of such a new physical difficulty was 1.23 (95 percent confidence interval, 1.02 to 1.47) for the continuously uninsured participants and 1.26 (95 percent confidence interval, 1.01 to 1.54) for the intermittently uninsured participants. CONCLUSIONS: The lack of health insurance is associated with an increased risk of a decline in overall health among adults 51 to 61 years old.

Activities of Daily Living↗
PubMed2001

Morbidity and cost implications of inadequate hemodialysis.

American hemodialysis patients have short lifespans, frequent hospitalizations, and aggregate Medicare inpatient expenditures of $4 billion/year. Dose of dialysis, as quantified by the parameter, Kt/V, corresponds strongly with survival and is estimated to be inadequate (Kt/V <1.2) in one fourth of patients. However, little is known about the morbidity and cost implications of inadequate dialysis. We sought to determine the independent relationship between dose of dialysis and (1) number of hospitalizations, (2) hospital days, and (3) Medicare inpatient reimbursements. We randomly selected 674 patients from all 22 hemodialysis units in northeast Ohio and examined hospitalizations, hospital days, and Medicare inpatient reimbursements for a 6-month interval following a 90-day quantification of dialysis dose. Every 0.1 decrease in Kt/V was independently associated with more hospitalizations (rate ratio, 1.11; 95% confidence interval [CI], 1.07 to 1.15), increased hospital days (rate ratio, 1.12; 95% CI, 1.03 to 1.22), and higher Medicare inpatient expenditures ($940; 95% CI, $450 to $1,440) after adjustment for patient age, sex, race, cause of renal failure, number of years on dialysis, and number of comorbid conditions. We estimate that increasing dialysis doses to a Kt/V of 1.2 for all patients nationally may decrease Medicare inpatient expenditures by $150 million annually. In conclusion, inadequate dialysis dose is independently associated with increased hospitalizations, hospital days, and Medicare inpatient expenditures. Improving dialysis adequacy may both improve patient morbidity and lessen health care costs.

Adult↗
PubMed1999

Practice patterns, case mix, Medicare payment policy, and dialysis facility costs.

OBJECTIVE: To evaluate the effects of case mix, practice patterns, features of the payment system, and facility characteristics on the cost of dialysis. DATA SOURCES/STUDY SETTING: The nationally representative sample of dialysis units in the 1991 U.S. Renal Data System's Case Mix Adequacy (CMA) Study. The CMA data were merged with data from Medicare Cost Reports, HCFA facility surveys, and HCFA's end-stage renal disease patient registry. STUDY DESIGN: We estimated a statistical cost function to examine the determinants of costs at the dialysis unit level. PRINCIPAL FINDINGS: The relationship between case mix and costs was generally weak. However, dialysis practices (type of dialysis membrane, membrane reuse policy, and treatment duration) did have a significant effect on costs. Further, facilities whose payment was constrained by HCFA's ceiling on the adjustment for area wage rates incurred higher costs than unconstrained facilities. The costs of hospital-based units were considerably higher than those of freestanding units. Among chain units, only members of one of the largest national chains exhibited significant cost savings relative to independent facilities. CONCLUSIONS: Little evidence showed that adjusting dialysis payment to account for differences in case mix across facilities would be necessary to ensure access to care for high-cost patients or to reimburse facilities equitably for their costs. However, current efforts to increase dose of dialysis may require higher payments. Longer treatments appear to be the most economical method of increasing the dose of dialysis. Switching to more expensive types of dialysis membranes was a more costly means of increasing dose and hence must be justified by benefits beyond those of higher dose. Reusing membranes saved money, but the savings were insufficient to offset the costs associated with using more expensive membranes. Most, but not all, of the higher costs observed in hospital-based units appear to reflect overhead cost allocation rather than a difference in real resources devoted to treatment. The economies experienced by the largest chains may provide an explanation for their recent growth in market share. The heterogeneity of results by chain size implies that characterizing units using a simple chain status indicator variable is inadequate. Cost differences by facility type and the effects of the ongoing growth of large chains are worthy of continued monitoring to inform both payment policy and antitrust enforcement.

Ambulatory Care Facilities↗
PubMed1999

[Comparison of exercise and histamine provocation tests in patients with bronchial asthma].

Fifty-eight asthmatic patients (22 men and 36 women), aged 17 to 61 years, participated in this study. Thirty-two of them had atopic asthma. Exercise test and histamine inhalation challenge test were performed in all subjects. Patients exercised on a bicycle ergometer for 6-8 min. to increase the heart rate to 80% of predicted maximal heart rate. Twenty-three patients had a bronchospasm following exercise. The PC20 values in patients with exercise induced asthma (Me = 0.35 mg/ml) were significantly lower (p = 0.006) than in subjects without exercise induced asthma (Me = 1.89 mg/ml). There was low but statistically significant correlation between PC20 and delta FEV1 after exercise (R(s) = 0.32; p = 0.01). These results suggest that there are not only similarities but also differences in pathomechanisms of bronchial hyperreactivity to histamine and exercise-induced bronchoconstriction. The lack of statistically significant correlation between diurnal PEF variation and PC20 values suggest that the former parameter cannot be considered as an useful marker of nonspecific bronchial hyperreactivity.

Adolescent↗
PubMed1998

First International Pharmacoeconomic Conference on Alzheimer's Disease: report and summary.

The First International Pharmacoeconomic Conference on Alzheimer's Disease (AD) was held in Amsterdam in July 1998. The meeting was held under the auspices of the International Working Group for Harmonization of Dementia Drug Guidelines (http://dementia.ion.ucl.ac.uk/harmon), bringing together academics, clinicians, purchasers, and representatives from industry. Presentations were given on the methodology of pharmacoeconomic studies in AD, particularly focusing on caregiver burden, quality of life (QOL), and resource utilization. Three economic models of AD were presented based on data from the United States, Canada, and the United Kingdom. In two studies, these data were then used to model the cost-effectiveness and effect on cost of treatment with donepezil. Both studies suggested a possible cost advantage for the use of donepezil, when compared with no placebo or treatment, particularly when donepezil is used appropriately in mild-to-moderate AD. These data need to be interpreted with care, as none of the cost or utility information were collected during the clinical trials. Additional data from a 2-year clinical trial of selegiline and vitamin E suggest that cognitive measures may be poor predictors of economic outcome, which is better measured directly. Both economic models of donepezil rely on short-term cognitive data to predict long-term outcome, a methodf that may not be useful in predicting economic savings. The issues facing pharmacoeconomists, researchers, clinicians, and families in the future were addressed in a series of workshops using a method of strategic futuring. The workshops attempted to see 7 years into the future for a range of areas, including consumer and caregiver use of pharmacoeconomic data; early detection and prevention; Japanese perspectives; activities of daily life and what will be daily life activities; caregiver burden; QOL at the end of life; new uses for new information and communication technology in clinical research; and physicians' use of pharmacoeconomic data. A range of exciting futures were predicted, although common themes that arose when considering barriers to achieving these futures included cost, education, political will, confidentiality, privacy, and ethics. The first conference was deemed to have been a success, having attracted more than 160 delegates and many distinguished speaker. A second conference is planned for the year 2000. Over the next 2 years, research needs to be broadened particularly in the methodological areas of resource utilization, QOL, and caregiver burden. Data from clinical trials with relevant economic and QOL outcomes will be needed by purchasers if drug treatments for dementia are to gain widespread use. It is also hoped that the models described at the meeting may become more freely available to politicians, purchasers, clinicians, and caregivers to help them make better decisions about treatment.

Aged↗
PubMed1998

[Diagnostic standard for differentiation between bronchial asthma and chronic obstructive pulmonary disease].

The aim of this study was to work out the simplified standard for distinguishing COPD from bronchial asthma. An overall sample of 150 individuals was used for statistical analysis. Sixty one were diagnosed as having COPD and 89 as suffering from asthma. For each patient the modified ATS-DLD-75-C questionnaire was filled out, and laboratory tests results were collected. Laboratory findings included: basic spirometry and flow-volume curve parameters, diurnal PEF variation, tests with bronchodilators (salbutamol, ipratropium bromide and corticosteroids), challenges with histamine and exercise, blood gas analysis, skin tests, chest X-ray, ECG, blood cell count, blood and sputum eosinophilia. Continuous variables were transformed into discrete (dichotomous) ones using commonly accepted threshold values. Then, sensitivity, specificity and accuracy indexes were calculated for each variable and for all possible sets of 2, 3 and 4 variables. Finally, 2 sets of 4 signs and symptoms were selected as the most characteristic of the diseases of interest. Asthma was diagnosed if 3 out of 4 following conditions were present: 1) episodes of shortness of breath and wheezing, 2) smoking index (cigarettes number per day x years of smoking) < or = 200, 3) PC20 < or = 8 mg/ml or delta FEV1 after bronchodilator > or = 15% predicted, 4) diurnal PEF variation > or = 20% predicted. COPD was recognised in the same way on the basis of: 1) productive cough, 2) smoking index > 200, 3) signs of emphysema on the chest X-ray, 4) maximal FEV1 < 80% predicted (after treatment). Diagnosis established using this model was correct in 76% and false (what was very important) in only 2.6% of cases. In the remaining 21% of patients it was uncertain (e.g. both of the diseases confirmed).

Adult↗
PubMed1998

[Specificity and sensitivity of some signs, symptoms and basic laboratory findings for differentiation between bronchial asthma and chronic obstructive pulmonary disease].

The aim of this study was to asses the importance of the most frequently observed signs and symptoms, as well as commonly used laboratory tests for differentiation between bronchial asthma and chronic obturative pulmonary disease (COPD). Sensitivity(Se) and specificity (Sp) indices were calculated for 140 analysed variables. Sixty one patients diagnosed as having COPD and 89 as suffering from asthma were analysed. For each patient the modified ATS-DLD-75-C questionnaire was filled out, and laboratory tests results were collected. Laboratory findings included: basic spirometry, diurnal PEF variation, bronchodilator tests with salbutamol, ipratropium bromide and corticosteroids, challenges with histamine and exercise, blood gas analysis, skin tests, chest X ray, ECG, blood cell count, blood and sputum eosinophilia. The results obtained have shown that there is no single parameter characterised by specificity and sensitivity that enable to differentiate between the diseases of interest with sufficient accuracy. Sputum expectoration for et least 3 months of the year (Se = 84%, Sp = 69%), smoking index (cigarettes number per day x years of smoking) > or = 200 (Se = 89%, Sp = 74%), have appeared to have the highest sensitivity and specificity for COPD. Most typical of asthma are: intermittent episodes of wheezing (Se = 89%, Sp = 69%), positive bronchodilator tests: with salbutamol (Se--73%, Sp--93%), with ipratropium bromide and with corticosteroids (Se--66%, Sp--94%) and diurnal variation of PEF > or = 20% predicted (Se--64%, Sp--92%). Challenge test with histamine is of limited value for differentiation bronchial asthma from COPD (Se--96%, Sp--40%), while blood eosinophilia, resting spirometry or blood gases are useless for this purpose.

Adult↗
PubMed1997

Hospital-insurer bargaining: an empirical investigation of appendectomy pricing.

Employers' increased sensitivity to health care costs has forced insurers to seek ways to lower costs through effective bargaining with providers. What factors determine the prices negotiated between hospitals and insurers? The hospital-insurer interaction is captured in the context of a bargaining model, in which the gains from bargaining are explicitly defined. Appendectomy was chosen because it is a well-defined procedure with little clinical variation. Our results show that certain hospital institutional arrangements (e.g. hospital affiliations), HMO penetration, and greater hospital concentration improve hospitals' bargaining position. Furthermore, hospitals' bargaining effectiveness has diminished over time and varies across states.

Appendectomy↗
PubMed1996

Payment source and the cost of hospital care: evidence from a multiproduct cost function with multiple payers.

This study investigates the capacity of hospitals to vary the intensity of their services based on patients' expected sources of payment. While the concept of price discrimination by hospitals based on payer generosity ("cost-shifting") has been discussed extensively, the notion that hospitals can adjust payer-specific marginal costs to reflect differences in reimbursement policies has not been studied in depth. To examine this issue. this analysis employs a multiproduct cost function with hospital outputs defined as admissions by payment source, controlling for the distribution and severity of illness ("casemix") for each payer. Marginal costs of casemix-adjusted discharges are obtained and compared for Medicare, Medicaid, Private Payers, and a residual category that includes uncompensated care. We find that indeed, payer-specific marginal costs generally reflect payer generosity.

Cost Allocation↗
PubMed1995

[Role of the autonomic nervous system (adrenergic, cholinergic and nonadrenergic, noncholinergic) in regulation of respiratory system function].

There is now recognized that the autonomic innervation of airways consists of classic adrenergic and cholinergic nerves as well as of a "third" - nonadrenergic noncholinergic (NANC) - nervous system. Taking into account its complex regulatory role can be crucial for better understanding of various phenomena attributable to bronchial asthma.

Adrenergic Fibers↗
PubMed1994

Medicare costs in urban and rural nursing homes: are differential payments required?

Medicare makes urban or rural location a critical variable, using it to group skilled nursing facilities (SNFs) to set ceilings for payment. Cost function analysis reveals that urban and rural SNF costs do, indeed, exhibit different responses to various cost factors, although urban and rural Medicare cost ceilings have been only pennies apart in recent years. The cost functions also show that marginal cost of caring for a Medicare patient is significantly greater than average cost, and larger for rural nursing homes. Most SNFs are underpaid when they receive their average cost for care provided to Medicare beneficiaries, but the differential is greater for rural SNFs. This is likely to have implications for Medicare beneficiaries' access to care in free-standing SNFs in rural areas.

Costs and Cost Analysis↗
PubMed1994

[Effect of vaporizing high doses of ipratropium bromide on lung ventilation in patients with chronic obstructive pulmonary disease and bronchial asthma].

Authors compared efficacy of high Atrovent doses and Salbutamol on pulmonary ventilation. Examinations were performed in 20 patients with BA and 20 patients with COPD. Each drug was given on separate days in increasing doses (0.04; 0.25 and 0.5 mg) of Atrovent and 0.2 mg of Salbutamol. Bronchodilatation was assessed by measurement of FEV1; FEF25%, FEF50%, FEF75%. Maximal effect in patients with COPD was reached with doses of 0.25 and 0.5 mg of Atrovent (delta FEV1(%) +22). Salbutamol and 0.04 mg of Atrovent were significantly less effective. In patients with BA Salbutamol (delta FEV1(%) +49) are likely to be more effective bronchodilator an Atrovent (delta FEV1(%) +26).

Albuterol↗
PubMed1992

The Medicare cost of renal dialysis. Evidence from a statistical cost function.

Medicare's End Stage Renal Dialysis Program currently costs more than $6 billion per year, which covers renal dialysis, kidney transplants and other life-saving medical care for 190,000 patients of all ages suffering from chronic renal failures. Medicare reimburses dialysis units for dialysis treatments using a formula based on accounting costs reported by a small sample of facilities. However, accounting methods may obscure the true economic costs of providing the different type of dialysis treatments such as hemodialysis, continuous ambulatory peritoneal dialysis, and continuous cycling peritoneal dialysis. In this study, a multiproduct, statistical cost function approach to obtain cost estimates was used. Results obtained in this study show that the average cost and marginal cost of hemodialysis treatments are generally in line with current reimbursement rates, whereas the average and marginal costs of continuous ambulatory peritoneal dialysis treatments may be below this rate. For in-center hemodialysis, which is the mainstay of all dialysis units, the authors found evidence of decreasing economies of scale at the mean facility size, but found constant returns to scale for other modalities. Some evidence of economies of scale from chain ownership of dialysis centers was discovered. Finally, the analysis indicates that the Medicare reimbursement formula may be outdated, and further research that could lead to the design of more "rational" payment rules is suggested.

Adult↗