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Biomedical subjects

G F Anderson

Publications and source records attributed to G F Anderson.

At least 37 records · Page 2Linked to original sources

Capitation, managed care, and chronic obstructive pulmonary disease.

Expenditure and utilization patterns of aged Medicare beneficiaries with chronic obstructive respiratory disease (COPD) (n = 42,472) were compared with all Medicare beneficiaries (n = 1,221,615) using a 5% nationally representative sample of aged Medicare beneficiaries participating in the fee-for-service program in 1992. Per capita expenditures for an aged Medicare beneficiary with COPD were 2.4 times the per capita expenditures for all Medicare beneficiaries. The most expensive 10% of Medicare beneficiaries with COPD accounted for nearly half of total expenditures for this population. Higher comorbidity, as measured by the Deyo-adapted Charlson index, was associated with higher expenditures. For Medicare Part B claims, internal medicine accounted for the largest portion of physician expenditures (14%). Per capita expenditures for pulmonologists were 7.5 times higher for beneficiaries with COPD compared with all Medicare beneficiaries. Results from this study suggest that there is a subgroup of individuals with COPD who are likely to be very expensive during the year. Additional analytic studies are needed to more specifically identify characteristics associated with these individuals. As more Medicare beneficiaries enroll in managed care and as physicians are increasingly being paid on a capitated basis this information will be useful to physicians as they monitor the care provided to patients and assess the financial risks they accept under capitation.

Aged↗

Patterns of expenditures and use of services among older adults with diabetes. Implications for the transition to capitated managed care.

OBJECTIVE: To examine health care use and expenditures among older adults with diabetes, investigate factors that are associated with higher expenditures, and describe the policy implications of caring for this population under managed care. RESEARCH DESIGN AND METHODS: A cross-sectional analysis of expenditures for individuals with diabetes over age 65 years from a nationwide 5% random sample of Medicare beneficiaries was conducted during 1992. All components of medical care covered under Medicare were examined. Multivariate analysis was used to assess the contribution of age, race, sex, number of diabetic complications, and comorbidity (Charlson Index) on total expenditures. RESULTS: On average, individuals with diabetes (n = 188,470) were 1.5 times (P < 0.0001) as expensive as all Medicare beneficiaries (n = 1,371,960). However, there were wide variations, with the most expensive 10% of beneficiaries with diabetes accounting for 56% of expenditures for individuals with diabetes and the least expensive 50% accounting for 4%. Acute care hospitalizations accounted for the majority (60%) of total expenditures, whereas outpatient and physician services accounted for 7 and 33%, respectively. There were no differences in the number of complications for all older adults with diabetes compared with those with the highest expenditures. However, the average number of hospitalizations was 1.6 times (0.53 vs. 0.34; P < 0.0001) higher, and the average length of stay was 2 days longer, among older adults with diabetes (P < 0.0001). In the regression model, age and male sex (factors currently used to set payment rates for Medicare managed care enrollees), and number of diabetic complications, but not race, were positively related to expenditures, yet had minimal predictive power (R2 = 0.0006). The addition of the Charlson Index, also positively related to expenditures, was able to explain up to 20% of the variation in total expenditures (R2 = 0.196). CONCLUSIONS: There are large variations in expenditures among older adults with diabetes. Because elderly beneficiaries with diabetes are more expensive than the average older adult, current Medicare capitation rates may be inadequate. To avoid selection bias and under-treatment of this vulnerable population under managed care, methods to construct fair payment rates and safeguard quality of care are desirable.

Age Factors↗

"Carving out" conditions from global capitation rates: protecting high-cost patients, physicians, and health plans in a managed care environment.

The purposes of this study were (1) to develop a method for identifying individuals with high-cost medical conditions, (2) to determine the percentage of healthcare spending they represent, and (3) to explore policy implications of "carving out" their care from managed care capitation. Annual payments over a 2-year period to enrollees of three health plans--a traditional managed care organization, and a state Medicaid program--were determined by using a cross-sectional analysis of insurance claims data. The main outcome measures were the number of enrollees with total annual payments in excess of $25,000 and the contribution of these high-cost enrollees to each health plan's total costs. Forty-one groups of diagnosis and procedure codes representing a combination of acute and chronic conditions were included on the list of carve-out conditions. Pulmonary insufficiency and respiratory failure together accounted for the largest number of high-cost individuals in each health plan. Solid organ and bone marrow transplants, AIDS, and most malignancies that required high-dose chemotherapy were also important. The carve-out list identified more than one third of high-cost individuals enrolled in the Medicaid program, approximately 20% of high-cost managed care enrollees, and 10% of high-cost fee-for-service enrollees. These data confirm that it is possible to identify high-cost individuals in health plans by using a carve-out list. Carving out high-cost patients from capitation risk arrangements may protect patients, physicians, and managed care organizations.

Adult↗

Chronic activation of protein kinase C by phorbol ester reduces calcium channel expression in chick sympathetic neurons.

Chronic activation of protein kinase C (PKC) has been implicated in regulation of Ca2+ entry responsible for normal development of transmitter properties in cultured sympathetic neurons. The idea that PKC alters the expression of Ca2+ channels was tested using phorbol 12,13-dibutyrate (PDB) which activates PKC and also supports survival of chick sympathetic neurons in the absence of nerve growth factor (NGF). Whole cell voltage-clamp showed that neurons supported by PDB for 2 days had significantly lower Ca2+ current density (0.243 +/- 0.025 pA/microm2) than those supported by NGF (0.356 +/- 0.033 pA/microm2). [125I]omega-Conotoxin GVIA binding showed that PDB-supported neurons had significantly lower maximum binding (617 +/- 223 fmol/mg protein) compared with those supported by NGF (1099 +/- 192 fmol/mg protein). These results support the conclusion that chronic activation of PKC limits the expression of N-type Ca2+ channels. A reduction in Ca2+ channel number is consistent with, and could account for the mature type Ca2+ handling and transmitter release properties seen in sympathetic neuro-effector preparations, sympathetic neurons co-cultured with their targets, and neurons supported by PDB.

Animals↗

International variation in ophthalmologic management of patients with cataracts. Results from the International Cataract Surgery Outcomes Study.

OBJECTIVES: To describe international variation in the management of patients with cataacts in 4 health care systems and to discuss the potential implications for cost and utilization of services. DESIGN: To characterize current clinical practice on patients with no coexisting medical or ocular conditions, a standardized questionnaire was sent to random samples of ophthalmologists in the United States (response rate, 82.5%), Canada (66.9%), and Barcelona, Spain (70.4%), and to all ophthalmologists in Denmark (80.1%). From the United States, 526 ophthalmologists who performed cataract surgery participated in the study; there were 276 from Canada, 89 from Barcelona, and 82 from Denmark. RESULTS: Although in all 4 sites most surgeons reported that they performed A-scanning, fundus examination, and refraction routinely before surgery, significant crossnational variation was observed in preoperative ophthalmic and medical testing. While preoperative medical tests were virtually unused in Denmark, they were widely used in the other sites. A significantly higher proportion of the surgeons in the United States and Barcelona reported that they performed less than 100 extractions per year compared with surgeons in Canada and Denmark (P < .001). A significantly higher proportion of the surgeons in the United States and Canada were performing predominantly phacoextraction compared with surgeons in Denmark and Barcelona (P < .001). Both within and across sites, considerable variation in number of follow-up visits and postoperative tests was observed. CONCLUSIONS: Significant international variation in the management of healthy patients with cataracts has been observed. If less intensive care is not associated with poorer outcomes, there is the potential for less costly care of patients with cataracts. Further research identifying the most cost-effective practices is needed.

Adult↗

International variation in anesthesia care during cataract surgery: results from the International Cataract Surgery Outcomes Study.

OBJECTIVES: To describe international variation in anesthesia care and monitoring during cataract surgery and to discuss its implications for cost and safety. METHODS: A standardized questionnaire was sent to random samples of ophthalmologists in the United States, Canada, and Barcelona, Spain, and to all ophthalmologists in Denmark. The survey was conducted in 1993 and 1994. Certified ophthalmologists who had performed 1 or more cataract extractions in the previous year were eligible for enrollment. RESULTS: The response rates were 62% in the United States (n=148), 67% in Canada (n=276), 70% in Barcelona (n=89), and 80% in Denmark (n=82). The anesthetic technique for cataract surgery varied significantly between sites (P<.001). Surgeons reported that retrobulbar blocks were used for 46% of the cataract extractions in the United States, 70% in Canada, 66% in Denmark, and 31% in Barcelona. In Barcelona, general anesthesia was used for 23% of the cataract extractions; it was used for less than 3% of the extractions at the other 3 sites. Peribulbar blocks or topical anesthesia was used for the remaining extractions. In the United States, Canada, and Barcelona, surgeons reported that vital functions were monitored during more than 97% of the extractions and anesthesia surveillance was used during more than 78% of the extractions. In Denmark, ophthalmologists reported that vital functions were monitored and anesthesia surveillance was used for 1% of the cataract extractions (P<.001). CONCLUSIONS: Substantial international variation in anesthesia care and monitoring during cataract surgery was observed. The findings suggest a need for further research to determine whether less intensive monitoring is cost-effective.

Anesthesia↗

Pediatric carve outs. The use of disease-specific conditions as risk adjusters in capitated payment systems.

OBJECTIVE: To address the issue of adverse selection in capitated payment systems by developing a list of disease-specific pediatric conditions (i.e., "carve outs") to be considered for separate reimbursement. DESIGN: A descriptive study using a large Medicaid database. INTERVENTION: With the use of fiscal year 1993 Washington State Medicaid cost data for 302,240 pediatric patients, a list of disease-specific carve outs was developed to meet the following criteria: high cost, low variability in cost, and association with a large proportion of medical spending. RESULTS: Six-hundred seventy-three patients (0.2%) in the database had annual costs totaling $25,000 or more. Ten percent of the cases accounted for approximately two thirds of spending, while the least expensive 70% of cases made up only 15% of the expenditures. Prematurity and complications of prematurity, neoplasms, congenital heart disease, organ transplantations, congenital anomalies, and respiratory problems were general categories of disease that met our criteria for a carve out. The association of a major surgical procedure with a diagnosis increased the predictive accuracy for high cost. CONCLUSION: Lists of disease-specific carve outs such as this one can be used by Medicaid plans and other insurers who are concerned about risk selection to identify conditions for separate reimbursement in capitated payment systems.

Adolescent↗

International applicability of the VF-14. An index of visual function in patients with cataracts.

PURPOSE: There is increased recognition that a rigorous approach to functional assessment should complement the assessment of clinical status. The authors compare the reliability, validity, and responsiveness to clinical change of a visual function index (VF-14) in non-U.S. and in U.S. patients with cataracts. DESIGN: An observational longitudinal study was performed. PARTICIPANTS: One thousand four hundred seven first eye cataract surgery patients were recruited in four international sites: Manitoba (Canada), Denmark, Barcelona (Spain), and the United States. INTERVENTION: Patients were evaluated before cataract surgery and at a 4-month postoperative follow-up visit. Patients completed the preoperative interview and the clinical examination (766 in the United States, 152 in Manitoba, 291 in Denmark, and 198 in Barcelona), and 91.3% of those (1284) also completed the 4-month postoperative follow-up interview and were evaluated postoperatively by an ophthalmologist. MAIN OUTCOME MEASURES: The authors used the following measures: the visual function index (VF-14), the Sickness Impact Profile (SIP), global measures of patients' trouble and satisfaction with vision, and best-corrected visual acuity (VA) in each eye. RESULTS: The VF-14 showed a high internal consistency reliability level in all sites (Cronbach's alpha coefficients > or = 0.84). Correlation of preoperative visual function index scores with the Vision-Related SIP was strong (r = -0.68 in non-U.S. and r = -0.57 in U.S. patients) and with VA in the eye with better vision was moderate (r = 0.40 and r = 0.27, respectively), the pattern of relationships being very similar among U.S. and non-U.S. patients. In patients with only first-eye surgery who reported that their initial trouble with vision had improved, the amount of change in visual function as assessed by the VF-14 (effect size) was large (1.01 for the non-U.S. patients and 1.17 for the U.S. patients). CONCLUSIONS: The non-U.S. versions of the visual function index (VF-14) analyzed are as reliable, valid, and responsive to clinical change as the original U.S. version. These versions are appropriate for international studies of cataract patients outcomes and possibly in routine clinical practice.

Aged↗

Patients' acceptance of waiting for cataract surgery: what makes a wait too long?

The patient's perspective about waiting for elective surgery is an important consideration in the management of waiting lists, yet it has received little attention to date. This study was undertaken to assess the acceptability of personal waiting times from the perspective of patients, and to examine waiting time and patient characteristics associated with the perception that a wait for cataract surgery is too long. The international prospective study was conducted in three sites with explicit waiting systems: Manitoba, Canada; Denmark; and Barcelona, Spain. Patients over the age of 50 years were recruited consecutively from ophthalmologists' practices at the time of their enlistment for first-eye cataract surgery. Anticipated waiting time, opinions about personal waiting time, and patients' visual and health characteristics were identified by means of telephone interviews. The 550 patients interviewed at the time of enlistment for surgery anticipated waits varying from < 1 to 24 months. Clinical visual acuity measures were obtained from patients' ophthalmologists/cataract surgeons. Results indicated that anticipated waiting time was the strongest predictor of patients' tolerance of waiting for cataract surgery. Patient dissatisfaction increased with the duration of the anticipated wait. Patients in all three sites were accepting of waits of three months or less, and considered waits exceeding six months to be excessive. Response to waits between three and six months varied across study sites. Patients with low tolerance for waiting had greater self-reported difficulty with vision, as assessed by a Cataract Symptom Score and expressed trouble with vision. Patients' acceptance of waiting was not associated with clinical visual acuity measures or socio-demographic characteristics. The patient perspective on acceptability of waiting times for cataract surgery suggests that restricting waiting times to less than six months and preferably less than three months and utilizing self-reported measures of visual difficulty in prioritizing patients may contribute to improved management of waiting systems. Patients are more tolerant of their personal waiting times than responses to questions about waiting for elective surgery in general would indicate, and appear to accept waiting times that are longer than those identified as reasonable by specialists.

Aged↗

Characterization of cocaine binding sites in the rat testes.

PURPOSE: An estimated 29 million individuals use cocaine in the United States. Studies have shown a high affinity for dose dependent binding of cocaine in the testes. Recent work done in our laboratory has shown that chronic administration of cocaine to male rats has an adverse effect on fertility and spermatogenesis by producing extensive morphological changes in the testes, leading to reduction in sperm production. As a first step toward understanding this process, we characterized and identified the pharmacological properties of [3H]cocaine binding sites in the testes. MATERIALS AND METHODS: Crude membranes from the testes were prepared from 35 days old male Sprague-Dawley rats. [3H]cocaine binding was measured by using the method of Madras et al. (1989) with modifications. The data from saturation binding assays were analyzed by Inplot (GraphPad Software, San Diego, CA) to determine the Kd and Bmax. RESULTS: Specific binding of [3H]cocaine was linearly dependent on membrane protein concentrations ranging from 0.2 to 8 mg./ml. The pooled data from three independent experiments revealed a mean affinity of 36 +/- 2.0 nM and Bmax of 1.84 +/- 0.13 pmol/mg. The present study demonstrates that testicular tissue has receptor protein that binds [3H]cocaine saturably and specifically. Competition displacement experiments revealed a shallow displacement curve for (-)cocaine and Win 35,428 with r2 = 0.96, indicative of multiple binding components. Computer analysis confirmed that a two component binding model was preferred statistically over a one component model in all three experiments (p < 0.001). CONCLUSION: The results from these studies suggest that the testicular tissue contains a protein that binds [3H]cocaine in a saturable and specific manner. It has a different sensitivity from the [3H]cocaine binding protein in the brain and placenta. Further clarification of the relationship between cocaine and its recognition site is necessary to understand the mechanism of testicular damage after cocaine exposure.

Animals↗

Technology coverage decisions by health care plans and considerations by medical directors.

OBJECTIVES: Decisions made by private health care plans as to whether to cover new medical technology have a significant impact on access, diffusion, and costs. This study describes the variation in health plan coverage of different laser technologies and the types of considerations used in making coverage decisions for them. METHODS: In a cross-sectional national survey of medical directors at private plans, medical directors indicated current coverage of 15 different laser therapies, and then ranked the top five considerations both in favor and against recommending coverage for three of the laser therapies (angioplasty, discectomy, and photodynamic therapy). The influence of explicit clinical information and/or plan characteristics on coverage and the importance of considerations was examined through multivariate analyses (multiple logistic or linear regression analysis). RESULTS: Overall, 231 medical directors responded from plans representing 66% and 72% of persons in US health maintenance organization and indemnity plans, respectively. Current coverage for 13 of the 15 laser therapies varied between 20% and 90%. For-profit and indemnity plans covered approximately two more of the different laser technologies than nonprofit plans and health maintenance organizations. Considerations most frequently listed in favor of and against recommending coverage across the three laser technologies were clinical, economic, and regulatory. Legal, competitive, and compassionate concerns were listed less frequently. Considerations were not uniform across laser therapies; they reflected the specifics of the technology under review. Plan characteristics influenced the ranking of considerations as well. For instance, health maintenance organizations were two to three times more likely than indemnity plans to list potential for decreased cost in favor of recommending coverage. CONCLUSIONS: These findings demonstrate that there is substantial variation in coverage of new technologies, indicating that a large proportion of the population covered by private health plans are ineligible for treatments that are routinely available to others. A greater range of medical therapy may be available for persons enrolled in indemnity and for-profit plans should their physicians choose to prescribe it. Clinical and economic considerations, including cost-effectiveness, predominate in coverage decisions for new technologies. The importance of considerations appears sensitive not only to specific clinical information, however, but also to characteristics of health plans.

Cross-Sectional Studies↗

Risk of endophthalmitis after cataract extraction: results from the International Cataract Surgery Outcomes study.

AIM: To estimate risk of infectious endophthalmitis after cataract extraction in Denmark and to compare results with the risk of this complication in the USA. METHODS: In the national Danish administrative hospital register, 19,426 patients were identified who underwent first eye cataract surgery from 1985 to 1987 and who were 50 years of age or older. Of these, 61 patients had postoperative endophthalmitis. RESULTS: A 12 month cumulative risk of rehospitalisation for endophthalmitis was estimated at 0.18% (95% CI 0.09-0.26) after extracapsular cataract extraction with lens implant. Advanced age, male sex, intracapsular cataract extraction, and anterior vitrectomy were all associated independently with an increased risk of postoperative endophthalmitis. When restricting the sample to patients aged 65 years or older, in order to allow comparisons to be made with the US National Study of Cataract Outcomes, a 12 month risk of 0.17% (95% CI 0.08-0.25) was estimated. The previously reported US risk of 0.12% is included in the confidence interval of the risk estimated in the Danish sample. CONCLUSION: Despite considerable differences in the healthcare systems, no statistically significant difference in outcome of surgery as measured by risk of endophthalmitis was shown between Denmark and the USA.

Aged↗

Expenditures for care of children with chronic illnesses enrolled in the Washington State Medicaid program, fiscal year 1993.

OBJECTIVE: We calculated expenditures for children with one of eight selected chronic health conditions who were enrolled in the Washington State Medicaid program and compared them with payments for all Medicaid-enrolled children. We examined variation in mean, median, and total expenditures and identified expenditure sources. METHODS: This study analyzed Medicaid claims data for 310 977 children aged 0 to 18 who were enrolled at any time in fiscal year 1993. Tracer conditions were used to examine expenditure variation within and between diagnostic groupings. A total of 18 233 children (5.9%) had at least one of the conditions. Expenditures were calculated based on payments made by the Medicaid program. RESULTS: Children with one of the eight selected conditions incurred mean expenditures of $3800, compared with $955 for all Medicaid-enrolled children. Mean payments associated with the selected conditions ranged from 2.5 times to 20 times more than payments to all children. Approximately 10% of children accounted for approximately 70% of the payments in general and in each diagnostic grouping. Variation in mean, median, and total expenditures was extensive among the conditions. For most conditions, inpatient stays accounted for the greatest proportion of expenditures; for some conditions, durable equipment, home nursing, and medication-related services accounted for substantial proportions of total expenditures. CONCLUSIONS: Medical care for children with selected chronic health conditions is 2.5 to 20 times more expensive than children in general, depending on the condition. A relatively few children account for the majority of expenditures. Extensive variation in mean, median, and total expenditures suggests that different conditions will need to be kept distinct for purposes of establishing payment rates. Children with certain conditions are vulnerable to restrictions in specific services, depending on what restrictions are imposed by a financing program. Further analyses are needed to identify risk-adjustment strategies to support delivery of high-quality services to this population of children as they migrate into managed-care environments.

Asthma↗

A comparison of three methods for estimating the requirements for medical specialists: the case of otolaryngologists.

OBJECTIVE: To compare three methods of computing the national requirements for otolaryngologists in 1994 and 2010. DATA SOURCES: Three large HMOs, a Delphi panel, the Bureau of Health Professions (BHPr), and published sources. STUDY DESIGN: Three established methods of computing requirements for otolaryngologists were compared: managed care, demand-utilization, and adjusted needs assessment. Under the managed care model, a published method based on reviewing staffing patterns in HMOs was modified to estimate the number of otolaryngologists. We obtained from BHPr estimates of work force projections from their demand model. To estimate the adjusted needs model, we convened a Delphi panel of otolaryngologists using the methodology developed by the Graduate Medical Education National Advisory Committee (GMENAC). DATA COLLECTION/EXTRACTION METHODS: Not applicable. PRINCIPAL FINDINGS: Wide variation in the estimated number of otolaryngologists required occurred across the three methods. Within each model it was possible to alter the requirements for otolaryngologists significantly by changing one or more of the key assumptions. The managed care model has a potential to obtain the most reliable estimates because it reflects actual staffing patterns in institutions that are attempting to use physicians efficiently. CONCLUSIONS: Estimates of work force requirements can vary considerably if one or more assumptions are changed. In order for the managed care approach to be useful for actual decision making concerning the appropriate number of otolaryngologists required, additional research on the methodology used to extrapolate the results to the general population is necessary.

Data Interpretation, Statistical↗

Augmented release of serotonin by adenosine A2a receptor activation and desensitization by CGS 21680 in the rat nucleus tractus solitarius.

Rat dorsomedial medullary brain segments containing primarily nucleus tractus solitarius (NTS) were employed for slice superfusion studies of electrically evoked [3H]serotonin ([3H]5-HT) release. Individual slices loaded with [3H]5-HT were stimulated two times, S1 and S2, at 3 Hz, 25 mA, 2 ms pulses for 1 min. Control NTS slices had a S2/S1 ratio of 0.94 (+/- 0.02). Superfusion of tissue slices with 0.1 nM to 100 nM 2-p-(2-carboxyethyl)-phenethylamino-5'-N-ethylcarboxamidoadenosine (CGS 21680), a selective adenosine A2a receptor agonist, for 5 min prior to the S2 stimulus produced a significant concentration-dependent increase in the S2/S1 fractional release ratio which was maximal (37.2% increase, P < 0.01) at 1.0 nM. However, superfusion of tissue slices with CGS 21680 over the same concentration range for 20 min prior to the S2 stimulus did not significantly alter the S2/S1 ratio from control release ratios. The augmented release of [3H]5-HT mediated by 1.0 nM CGS 21680 with 5 min tissue exposure was abolished by 1.0 nM 9-chloro-2-(2-furanyl)-5, 6-dihydro-[1,2,4]-triazolo[1,5-c]quinazolin-5-imine (CGS 15943) as well as by 100 nM 8-(3-chlorostyryl)caffeine (CSC), both A2a receptor antagonists, but not by 1.0 nM 8-cyclopentyl-1,3,-dipropylxanthine (DPCPX), the A1 receptor antagonist. These results indicate that CGS 21680 augmented the evoked release of [3H]5-HT in the NTS by way of activation of presynaptic adenosine A2a receptors. It was also apparent that this population of adenosine A2a receptors in the NTS desensitized within 20 min since the augmenting action of CGS 21680 on evoked transmitter release was not evident at the longer time interval.

Adenosine↗

The effects of 5'-N-ethylcarboxamidoadenosine on evoked release of [3H]serotonin in the rat nucleus tractus solitarius.

5'-N-Ethylcarboxamidoadenosine (NECA) a non-selective adenosine A1 and A2a receptor agonist was employed in stimulated (3 Hz, 25 mA, 1 min) superfused nucleus tractus solitarius (NTS) brain slices loaded with [3H]5-hydroxytryptamine ([3H]5-HT), and ligand binding with [3H]NECA on NTS membranes. Superfusion of NTS slices with 1.0 and 3.0 nM NECA for 5 min prior to S2 stimulation produced an augmented release of [3H]5-HT (35.7%) above the control S2/S1 ratio. When the duration of NECA perfusion was increased to 20 min prior to S2, the S2/S1 ratio was depressed 21% at 1.0 nM for [3H]5-HT release. The augmented release of [3H]5-HT by NECA at 5 min was blocked by the adenosine A2a antagonist 8-(3-chlorostyryl)caffeine (CSC; 100 nM), and was reduced but not blocked by the A1 antagonist 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 10 nM). Saturation binding assays with [3H]NECA on NTS membranes showed two binding sites, a high affinity site with a KD 2.18 nM and low affinity site with a KD of 44.9 nM. With the selective adenosine A2a antagonist CSC the high affinity site was blocked while 10 nM DPCPX, the A1 antagonist, reduced binding of the low affinity site, but did not abolish it. NECA binds to two different adenosine receptor sites in NTS membranes with the A2a receptor being the high affinity site. The same A2a site is associated with the augmented neurotransmitter release of [3H]5-HT with 5 min tissue exposure since it is blocked by CSC. Longer tissue exposure to NECA resulted in desensitization and finally inhibition of release possibly associated with adenosine A1 receptors.

2-Chloroadenosine↗

The review process used by US health care plans to evaluate new medical technology for coverage.

OBJECTIVE: To examine the process and information used by medical directors (MDs) of private health plans to make medical coverage determinations for new medical technologies, and to assess the influence of plan characteristics on the process. DESIGN: Cross-sectional national survey. PARTICIPANTS: Two hundred thirty-one MDs at private health plans representing 66% and 72% of the US population covered by HMOs and indemnity plans, respectively. MEASUREMENTS: Actual and optimal review process, final decision authority, sources, and evidence used for technology coverage decisions. RESULTS: In 96% of plans, MDs take part in the medical policy review process for new technology. However, MDs have final authority over coverage decisions in only 27% of plans. Indemnity plans are more likely to assert that MDs should be responsible for final decisions, odds ration (OR) = 3.3 (95% confidence interval [95% CI] 1.4, 10). Optimal sources of information of new technology were journals, medical society statements or practice guidelines, and opinions of national experts. Actual sources of information used differed from optimal ones; local experts were used more often than is considered optimal (p < .001). For-profit plans were more likely than nonprofit plans to use national experts, OR 2.5 (95% CI 1.3, 5.0), and practice guidelines, OR 5.0 (95% CI 2.5, 10). Randomized trials (94% of MDs) meta-analyses (61%), and reviews (42%) were considered the best evidence for making coverage decisions. Barriers to making optimal decisions were lack of timely evidence on effectiveness and cost-effectiveness, not legal or regulatory issues; HMO, small, and nonprofit plans were two or three times more likely to list lack of cost-effectiveness data than their counterparts (p < .05). CONCLUSIONS: Although MDs are nearly always involved in the technology evaluation process, a minority of MDs retain final authority over coverage decisions. Evidence from strong scientific research designs is the most frequently cited basis for decisions, but there is need for more timely, rigorous scientific evidence on medical interventions. How a health plan evaluates a new medical technology for coverage varies with identifiable plan characteristics.

Cross-Sectional Studies↗

Awareness of providers' use of new medical technology among private health care plans in the United States.

In a national survey of medical directors at 231 U.S. private health care plans that cover over two thirds of the privately insured population, we studied whether medical directors are aware when a new technology, such as laser therapy, is being used in procedures for which claims are submitted, the factors alerting them to such use, and the factors prompting them to make a specific coverage decision for the technology. We also examined possible associations between health plans' characteristics (HMO versus indemnity, size, profit status, and time in operation) and their medical directors' awareness of the use of technologies, factors alerting medical directors to their use, and factors prompting specific coverage decisions. The majority of plans were generally not aware that laser technology was being used when it was billed under a general billing code, raising the possibility that less effective or less safe technologies could be introduced rapidly into the treatment of insured populations. Nonprofit and older plans were less likely to be aware that lasers were used in some procedures than for-profit and younger plans.

Analysis of Variance↗