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Biomedical subjects

G F Anderson

Publications and source records attributed to G F Anderson.

At least 19 recordsLinked to original sources
PubMed1992

Access to recombinant erythropoietin by Medicare-entitled dialysis patients in the first year after FDA approval.

OBJECTIVE: Examine access to recombinant human erythropoietin (rHuEPO) by dialysis-dependent end-stage renal disease (ESRD) patients during the first year after FDA approval for use in clinical practice and Medicare coverage. DESIGN: Longitudinal and cross-sectional claims data analyses. SETTING: All US providers of outpatient dialysis treatment. PATIENTS: 126,201 Medicare-entitled dialysis patients (approximately 93% of all US dialysis patients). OUTCOME MEASURES: Percentage of patients who received rHuEPO, odds of receiving rHuEPO according to patient characteristics, and cost of rHuEPO to Medicare. RESULTS: One year after FDA approval, 52% of all dialysis and 60% of in-center hemodialysis patients who regularly had Medicare-paid dialysis services received rHuEPO at a monthly cost to Medicare of $19 million (18% of Medicare ESRD outpatient expenditures and 6% of all ESRD program expenditures). Blacks were less likely than whites to receive rHuEPO (odds ratio, 0.88; 95% confidence interval, 0.86 to 0.91). Home peritoneal and hemodialysis patients were less likely than in-center hemodialysis patients to receive rHuEPO (odds ratios, 0.17 and 0.22, respectively; 95% confidence intervals, 0.16 to 0.17 and 0.20 to 0.24, respectively). Use of rHuEPO varied across geographic regions. The odds of receiving rHuEPO were lower for patients of male vs female sex, of ages 35 through 64 years vs less than 35 years and greater than 65 years, with a longer history of ESRD, with polycystic kidney disease vs other causes of ESRD, and receiving care in nonprofit vs for-profit facilities. First-month hematocrits were slightly higher (1.2 percentage points) for patients starting rHuEPO in the 12th month than in the first month after FDA approval. CONCLUSIONS: With prompt insurance coverage, the majority of Medicare-entitled dialysis patients received rHuEPO following widespread availability. Factors that may not be related to clinical need (race, setting of care, and geography) possibly influenced early patient access. More attention should be paid to monitoring the appropriate use of high-cost biotechnologic therapy.

Adolescent↗
PubMed1992

Results of colectomy in elderly patients with colon cancer, based on Medicare claims data.

Currently available estimates of outcomes following colon resection in elderly patients with colon cancer are based on series collected at academic medical centers. We used Medicare Part A claims and enrollment records of a 5% nationally random sample of elderly Medicare beneficiaries from 1983 to 1985 to estimate how patient age and sex affected perioperative mortality and 1- and 2-year survival rates among elderly patients undergoing a colon resection procedure for colon cancer. Among the 5,586 individuals in our data set, the overall perioperative mortality rate was 5.0%, ranging from 3.3% in beneficiaries 66 to 69 years of age to 9.3% in those 85 years of age and older. Men had a 31% higher perioperative mortality rate than women (5.8% versus 4.4%, p less than 0.05). The overall postoperative survival rates at 1 and 2 years were 72% and 63%, respectively, decreasing with increasing age, but were similar in men and women. This analysis provides age- and sex-specific estimates of outcomes following surgery for elderly patients with colon cancer that are more precise and have more potential for generalization than those that were available previously.

Age Factors↗
PubMed1992

Evaluation of the hoof and foot relevant to purchase.

The equine hoof and foot are the most commonly affected anatomic sites of lameness encountered during purchase examination of the performance horse. This article presents a thorough, systematic approach to the clinical evaluation of the hoof and foot relevant to the pre-purchase examination. Normal and abnormal conditions are discussed with reference to their potential effects on future performance and soundness. Proper trimming, balancing, and shoeing principles are emphasized.

Animals↗
PubMed1992

Decreased cardiorespiratory effects of neuropeptide Y in the nucleus tractus solitarius in diabetes.

It has been observed that diabetes results in increased neuropeptide Y (NPY) in various brain regions, especially the paraventricular nucleus, which projects to the nucleus of the solitary tract (NTS). Because previous studies indicated a pathophysiological relationship between diabetes and NPY, we investigated the effect of diabetes on the sensitivity of NTS-mediated responses to NPY administration. Rats were made diabetic using streptozocin (55 mg/kg iv) and maintained for 48 to 50 days. Normal and streptozocin-diabetic rats were anesthetized with urethan and alpha-chloralose, instrumented for cardiovascular and respiratory monitoring, and positioned in a stereotaxic apparatus. The brain stem was exposed surgically. NPY (0.15 nmol/kg) was microinjected into the NTS and the cardiovascular and respiratory parameters were monitored for 60 min. Diabetes increased systolic (SAP), diastolic (DAP), and mean (Pa) blood pressure but not pulse pressure (PP) and heart rate (HR). Respiratory parameters were not altered. NPY significantly decreased SAP, DAP, Pa, PP, HR, respiratory rate, and minute volume in normal animals. In diabetic animals, NPY also decreased SAP, DAP, and Pa but pronouncedly increased PP. Although NPY decreased the SAP and Pa in diabetic animals, the response was attenuated compared with normal animals. The respiratory parameters and HR of diabetic animals, unlike normal animals, did not respond to NPY administration. We conclude that chronic diabetes results in a decreased sensitivity to NTS-mediated responses and that the hyporesponsiveness of the NTS to NPY modulation may be important in the tendency toward elevated blood pressure and hypertension in diabetes.

Analysis of Variance↗
PubMed1992

The courts and health policy: strengths and limitations.

In recent years the nation's courts have expanded their influence in health policy in four areas: reviewing insurers' coverage decisions, deciding the adequacy of Medicaid payment rates to hospitals and nursing homes, arbitrating hospital mergers, and assessing hospitals' tax-exempt status. The major problem with developing health policy through the courts is that the courts' focus will be the concerns of the individuals or groups involved in specific cases, not the broader implications and overall objectives of the health care system. As alternatives to litigation to resolve policy conflicts, scholars have suggested negotiation, binding arbitration, clarification of legislative language, administrative courts, contract revision, and general restructuring of the decision-making process.

Charities↗
PubMed1991

Cost-effectiveness of extracorporeal shock-wave lithotripsy versus cholecystectomy for symptomatic gallstones.

To evaluate the cost-effectiveness of extracorporeal shock-wave lithotripsy vs. cholecystectomy for symptomatic gallstones, a model was constructed that projects charges and survival for both treatments. For a 45-year-old woman with one small stone, treatment with extracorporeal shock-wave lithotripsy rather than cholecystectomy is projected to result in an average gain of only 3 days of life and an average increase in direct medical charges of $1729 over 5 years of follow-up. The resulting marginal cost-effectiveness of extracorporeal shock-wave lithotripsy vs. cholecystectomy is $216,000 of extra charges per year of life gained with extracorporeal shock-wave lithotripsy. Extracorporeal shock-wave lithotripsy is projected to be much more cost-effective for elderly than for young patients (10-20-fold difference), but considerably less cost-effective for multiple stones than a single stone (2-4-fold difference), and less cost-effective for women than men (twofold difference). Adjusting for effects of morbidity on quality of life, extracorporeal shock-wave lithotripsy is projected to have slightly better quality-adjusted survival than cholecystectomy for the small subset of patients with one stone (by 8 to 43 days at 5 years) but not for young patients with multiple stones. It is concluded that decisions about appropriate use of extracorporeal shock-wave lithotripsy should consider the effects of patient characteristics on clinical and economic outcomes.

Aged↗
PubMed1991

Effect of decentralization and partial outflow obstruction on cholinergic receptors in urinary bladder of rabbit.

In this study we have examined the cholinergic receptor density on the detrusor smooth muscle from rabbits with decentralized autonomous bladders and animals with partial outlet obstructions using (3H) quinuclidinyl benzilate ([3H] QNB). Decentralized spinal bladders were obtained from rabbits made paraplegic by a twenty-minute ischemic lesion to the lumbar and sacral spinal cord. Bladder tissues from these rabbits were studied from one, two, five, and nine-day intervals after the ischemic lesion. The affinity of the muscarinic binding sites for (3H) QNB was virtually unchanged at any of the time intervals, while the total Bmax was significantly reduced at one and two days but recovered to normal levels by the fifth and ninth day after the ischemic lesion, provided the bladder had been effectively manually emptied on a regular basis. In a parallel study animals with a partial outlet obstruction or spinal animals with marked bladder distention at the time of sacrifice showed that the cholinergic receptor density was significantly reduced.

Animals↗
PubMed1991

Electromechanical effects of menadione on isolated rat heart in relation to oxidative stress.

Although Ca2+ overloading has been observed in hepatocytes and in the isolated liver treated with 0.2 mM menadione, it has not been determined if menadione has similar effects on cardiac tissue and, if so, whether Ca2+ overloading leads to cardiac contracture, and if such an event results from plasma membrane peroxidation initiated by oxidative stress. The present study reveals that when the isolated heart is perfused with 0.2 mM menadione for 30 min, it shows Ca2+ overloading, which can not be reversed even after 30 min of drug-free perfusion. The time courses of glutathione, ethane, and LDH release from the hearts do not show a parallel pattern of abnormality between 30 and 60 min, indicating that contractile failure precedes the development of lipid peroxidation or plasma membrane disintegration. The evidence that the plasma membrane of menadione-treated rat cardiac tissue remains intact is supported by the observation that the resting membrane potential of the atrium remains virtually unchanged during the 30 min of drug exposure and then gradually falls (-67 +/- 3.1 vs. -76 +/- 2 mv) only during the last 10 min of the drug washout. Interestingly, even after the atria are treated with menadione for 30 min and followed by washout of 30 min, and have shown calcium overloading, as evidenced by contracture, they are still capable of generating action potentials in response to electrical field stimulation.

Animals↗
PubMed1991

Blood transfusion costs: a multicenter study.

The cost of delivering a unit of blood (whole blood or red cells) to a hospitalized patient was examined in 19 United States teaching hospitals. The average hospital acquisition cost was calculated by using the prices charged by regional blood centers for blood products. To this cost was added an estimate of costs incurred by hospitals for handling, testing, and administering blood. Across study sites, the average hospital cost per unit transfused was $155 and the average charge to the patient was $219. Acquisition cost, the price that hospitals pay for blood, was 37 percent of the total cost to the hospital; the other 63 percent of the hospital cost included costs for blood bank handling (13%), laboratory tests (43%), and blood administration (7%). Significant variations in blood transfusion cost were found within our sample. Most of the variability can be attributed to geographic location of the blood supply source, type of red cell product transfused, prices charged by blood transfusion services, and the frequency of laboratory tests. The results of this transfusion cost study may be helpful in determining the costs of health care delivery, especially when blood transfusions are indicated.

Blood Transfusion↗
PubMed1991

Accuracy of Medicare claims data for estimation of cancer incidence and resection rates among elderly Americans.

To explore the reliability of Medicare Part A claims data for clinical and health services research related to the care of patients with cancer, the authors compared estimates of the incidence of and resection rates for cancer of the breast, colon, and lung derived from analysis of Medicare Part A data versus data from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. Incidence rates of breast, colon, and lung cancer estimated from Medicare Part A data were within 6% of estimates derived from SEER data. Resection rates estimated from Medicare Part A data, in contrast, were 12% to 27% lower than resection rates based on SEER data. This discrepancy is not explained by variations in practice between regions participating in versus those not participating in the SEER registries but may be due to undercoding of surgical procedures in Medicare Part A data. This analysis suggests that Medicare data can provide useful insights into the care of patients with cancer, but research regarding inpatient procedures employed in management of cancer should be based on analysis of Medicare Parts A and B data combined.

Abstracting and Indexing↗
PubMed1991

Use of Medicare claims data to evaluate outcomes in elderly patients undergoing lung resection for lung cancer.

OBJECTIVE: To estimate, using Medicare claims data, the outcomes in elderly Americans undergoing lung resection for lung cancer. DESIGN: We used discharge diagnosis and procedure codes in 1983 to 1985 Medicare hospital (part A) claims records to identify patients who underwent lung resection for lung cancer; we assessed perioperative, one-year, and two-year survival using Medicare enrollment file data. PATIENTS: From a nationally random sample of 1,138,000 Medicare beneficiaries over 65 years of age, we identified 1,290 individuals who fulfilled our definition for lung resection for lung cancer. MEASUREMENTS AND MAIN RESULTS: Overall perioperative (30-day) mortality was 7.4 percent. Postoperative survival at one and two years was 69 percent and 54 percent, respectively. Male sex, older age, and pneumonectomy, as opposed to a lesser procedure, were associated with reduced perioperative and one-year and two-year survival. The adverse effect of advanced age on one-year and two-year survival following lung resection was not explained by the lower life expectancy of older individuals. CONCLUSIONS: Medicare claims data can be used to estimate likely outcomes for elderly patients undergoing surgery for lung cancer. Expected outcomes vary with the patient's age, sex, and the type of surgical procedure performed.

Aged↗
PubMed1990

Impact of claims data research on clinical practice.

Despite their potential utility, clinicians are skeptical about claims data as a substrate for clinical research. Clinician's concerns are centered on two issues-the quality of the data and the fairness of comparisons that are made. To increase the impact of claims data research on clinical practice, several strategies should be pursued.

Humans↗
PubMed1990

Risk reduction from low osmolality contrast media. What do patients think it is worth?

Decisions regarding the use of and reimbursement for new medical technologies frequently involve complex cost-quality trade-offs. Among physicians, hospital administrators, and insurers, interindividual variation in the value of benefits attributable to these technologies often leads to conflicting opinions about their appropriate use. Although society now encourages patient involvement in such decisions, few methods for obtaining patient valuations have been developed and systematically applied. In order to assess patient valuations of a particular new technology, low osmolality contrast media (LOM), a survey of 100 outpatients was conducted. Participants were asked about their willingness to pay (WTP) for the benefits of this expensive medical technology. Of the 95 subjects who completed the study questionnaire, a majority were unwilling to pay the minimum extra per procedure cost of LOM ($50) in return for a reduced risk of minor side effects alone (pain, nausea, hives, and flushing). For a reduced risk of both major side effects (death, renal insufficiency, severe allergic reaction, and cardiac arrhythmia) and minor side effects, the median WTP was $50; patient income and education were directly associated with WTP $50 or more. We conclude that similar WTP surveys may be helpful in addressing other difficult cost-quality issues.

Adult↗
PubMed1990

Circadian rhythms of human pineal melatonin, related indoles, and beta adrenoreceptors: post-mortem evaluation.

Human pineal glands obtained from 77 post-mortem sources from various age groups and times of death were used to examine the 24-hour cycle of serotonin (5-HT), melatonin, N-acetylserotonin (NAS), and beta adrenoceptor density. Pineal glands were divided sagittally and a single half was used to measure 5-HT, NAS, and melatonin concentrations, while the remaining half from the same gland was employed to assess changes in the density of beta adrenoceptors on partially purified membranes. The results show that density of pineal beta adrenoceptors was relatively constant between midnight and 18.00 h and became significantly higher between 18.00 and 20.00 h as measured by ligand saturation binding experiments using (125-I) iodocyanopindolol. The receptor affinity of all of the samples assayed remained in relatively narrow range near 58 pM and only changes in the relative receptor density were apparent. The up-regulation of receptors coincided with an increase in the concentration of 5-HT that began to rise between 16.00 and 20.00 h and became maximal between 20.00 and midnight. NAS, the immediate precursor of melatonin, was also at maximal levels between 20.00 h and midnight. Both 5-HT and NAS began declining after midnight and this change corresponded to the maximal pineal gland concentration of melatonin between midnight and 4.00 h. It is therefore suggested that the up-regulation of beta adrenoceptors noted during the late afternoon and early evening hours corresponds to the increased synthesis of 5-HT and the subsequent conversion to NAS. These events are followed by the highest accumulation of melatonin after midnight and represent the synthesis of melatonin from its precursor NAS in a sequential pattern.

Adolescent↗
PubMed1990

Setting payment rates for capitated systems: a comparison of various alternatives.

Numerous proposals have been suggested to revise the current adjusted annual per capita cost (AAPCC) method for paying HMOs in the Medicare program. Several evaluations of the various alternatives conclude that including a prior utilization variable is the most promising alternative. In this paper, using statistical and other criteria, we compare the current AAPCC method with three different prior utilization models. The results suggest that all three prior utilization models can predict expenditures for either individuals or a group--drawn from a cross section and a risk selected sample of aged Medicare beneficiaries--more accurately than the AAPCC method. Of the three prior utilization measures, Payment Amount for Capitated Systems (PACS) predicts actual expenditures most accurately.

Capitation Fee↗