Geographic variation in Medicare surgical fees.
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Fee Schedules↗
Biomedical subjects
J B Mitchell
Publications and source records attributed to J B Mitchell.
Using physician time and complexity to identify mispriced procedures.
Physician fees have come under increasing scrutiny as policymakers attempt to constrain Medicare outlays. Our study tests the hypothesis that relative fees can be explained in terms of the physician effort involved. Our regression results show that the majority of the variation in Medicare allowed charges can be justified in terms of the physician time involved and the complexity of the procedure. Nevertheless, some surgical procedures were identified as being "overpaid" relative to their reported time and complexity, while other services appeared "underpaid," especially visits. Our methodology provides a tool for identifying "mispriced" procedures, should Congress continue its current policy of making adjustments to individual fees.
Costs and Cost Analysis↗
Feasibility of case-based payment for inpatient radiology, anesthesia, and pathology services.
This paper evaluates a proposal to include inpatient radiology, anesthesia, and pathology (RAP) services in the Medicare PPS hospital payment rate. One hundred percent Medicare claims data from four states were used to simulate the potential redistributive effects of such a payment change on hospitals. The DRG classification system was found to explain more than half the variation in Part B charges for inpatient RAP services. Surgical cases caused most of the explained variation. Rural hospitals are the most likely to win, largely for three reasons: less seriously ill patients within-DRG; limited availability of less expensive technology; and greater use of nurse anesthetists in lieu of anesthesiologists. Teaching hospitals, on the other hand, would lose money, principally because of the cost of extra diagnostic testing for teaching purposes. Redistributive effects could be minimized by making outlier and indirect medical education adjustments.
Alabama↗
Gastric emptying: influence of prolonged exercise and carbohydrate concentration.
Gastric emptying: influence of prolonged exercise and carbohydrate concentration, Med. Sci. Sports Exerc., Vol. 21, No. 3, pp. 269-274, 1989. The purpose of this study was to examine the effects of serial feedings of different concentrations of carbohydrate (CHO) on gastric emptying and to compare the rates of gastric emptying at rest and during prolonged exercise. Solutions of 0, 6, 12, and 18 g. 100 ml-1 (WP, CHO-6, CHO-12, and CHO-18, respectively) were tested. Ten trained male cyclists performed five trials involving 120 min of cycling. The first 105 min were at 70% of VO2max, and the final 15 min were an all-out self-paced performance ride. In one of the five trials, the subjects rode intermittently, completing seven 15-min rides at 70% of VO2max, with 3 min of rest between each ride. Every 15 min, approximately 150 ml (8.5 ml.kg-1.h-1) of one of the four test solutions were consumed. (In the intermittent trial, the CHO-12 solution was used.) Subjects were also tested during 120 min of seated rest using the above feeding schedule (6% solution). Gastric residue was determined by stomach aspiration following the performance ride. The volumes emptied during the CHO-12 and CHO-18 trials (1,049.8 and 889.2 ml) were significantly different from each other and were less than during the WP and CHO-6 trials (1,210.3 and 1,185.6 ml) (P less than 0.05). CHO delivery was significantly higher in the CHO-12 and CHO-18 trials (126 and 160 g) compared to the CHO-6 trial (71.1 g).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Chymopapain chemonucleolysis versus surgical discectomy in a military population.
From 1983 to 1987, 100 consecutive patients with lumbar herniated nucleus pulposus were treated with either chymopapain chemonucleolysis (51 patients) or surgical discectomy (49 patients). The chymopapain-treated group was followed for an average of 16 months and the surgically treated group was followed for an average of 12 months. All patients had to be candidates for both procedures and were grouped for therapy based on their preference. The groups were similar in military duty status, history, age, gender, duration and character of symptoms, physical findings, and computed tomography/myelogram results. Satisfactory outcomes were achieved in 40 of 51 (78%) chymopapain-treated patients and in 39 of 49 (80%) surgically treated patients. Seventy-eight percent of the chymopapain group and 79% of the surgery group ultimately returned to full military duty. Of the nine initial chymopapain failures, eight were successfully treated with surgical discectomy. There were fewer complications, 4% versus 10%, in the chymopapain group. The authors now consider chemonucleolysis as the final conservative measure prior to surgery, rather than an alternative to surgical discectomy.
Adult↗
Halogenated pyrimidines as radiosensitizers for high-LET radiation.
The incorporation of iododeoxyuridine (IdUrd) into Chinese hamster cells was examined as a possible radiosensitizer for fission spectrum neutrons. Dose-response curves comparing both X rays and neutrons in the same cell line with the same IdUrd replacement showed a similar radiation enhancement for IdUrd incorporation. Enhancement ratios at the 1% survival level were 1.8 for X rays and 1.5 for fission spectrum neutrons. While the mechanism of this enhancement in the response for fission neutron radiation is unclear, these positive data should support further exploration to determine if halogenated pyrimidine incorporation results in sensitization for neutron energies employed in therapy.
Animals↗
212Bismuth linked to an antipancreatic carcinoma antibody: model for alpha-particle-emitter radioimmunotherapy.
For comparison of cytotoxicity from alpha-particle irradiation with that from conventional x-irradiation, 212Bi, an alpha-emitting radionuclide, was attached to a monoclonal antibody that recognizes a cell surface antigen on human pancreatic carcinoma cells. For a given level of survival, the 212Bi-antibody complex was found to be approximately 20 times more efficient in cell killing than x-irradiation and 5 times more cytotoxic when compared with the cytotoxicity of an antigen-negative cell line or an isotype-matched control antibody. High linear energy transfer radioimmunotherapy using alpha emitters linked to monoclonal antibodies may be useful in vivo and in vitro for selectively killing target cell populations, especially those resistant to other forms of treatment.
Antibodies, Monoclonal↗
Simulating policy options for psychiatric care in general hospitals under Medicare's PPS.
Psychiatric hospitals and certain distinct part psychiatric units of general hospitals are currently exempt from diagnosis related group (DRG)-based payment under Medicare's prospective payment system (PPS), in large part due to concern about the degree to which such payment would match historical costs for these facilities. This communication simulates DRG-based payments for psychiatric admissions to general hospitals under the PPS and also under a modified version of the PPS. Two major types of modifications are made: (1) an increase in the role of outlier payments and (2) a restructuring of the DRG classification to allow for a difference in the basic payment rate, depending on whether or not care is provided in a facility that is currently exempt. When compared with cost data from just before the start of the PPS, the simulation results show the degree to which these hypothetical modifications will decrease the systematic risk of general hospitals with exempt units from receiving payments that fall short of costs.
Costs and Cost Analysis↗
Role of glutathione and other endogenous thiols in radiation protection.
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Animals↗
Radiation sensitivity and study of glutathione and related enzymes in human colorectal cancer cell lines.
A panel of 13 human colorectal cell lines was studied, with these lines exhibiting a histological profile similar to that observed in clinical practice. In the five lines tested, variable sensitivity to radiation was observed, from the relatively sensitive NCI-H716 to the highly resistant line NCI-H630, with the latter cell line derived from a patient who had previously received radiation treatment. Glutathione levels and glutathione related enzyme activity varied widely between all 13 cell lines, showing no relationship to radiation sensitivity. The variability observed suggests that some colonic tumours may be responsive to radiation, although their identification remains difficult. However, this may prove possible by incorporation of recently developed cell adhesive matrix assays using survival following a 2 Gy radiation dose as a parameter of radiation sensitivity. This panel of human cancer cell lines offers an ideal model for the study of parameters affecting the radiosensitivity and chemosensitivity pattern of colorectal cancer cells.
Cell Line↗
Trypanocidal activity of free and carrier bound daunorubicin.
Activities of a range of macromolecular conjugates of daunorubicin against Trypanosoma brucei rhodesiense in vitro and in vivo are described and compared to those of free daunorubicin. Conjugates tested were daunorubicin attached to bovine serum albumin by (i) a labile 'glutaraldehyde' linkage (D-BSAG), and (ii) a stable succinyl linkage (D-BSAS), daunorubicin covalently linked to agarose beads (D-AG), and daunorubicin adsorbed onto polyisobutylcyanoacrylate nanoparticles (D-PICA). Trypanocidal activity in vitro was retained in all except D-BSAS, whereas in vivo only D-BSAG had any activity. The results indicate that daunorubicin must be released from the conjugate before it can exert its activity.
Animals↗
Chemosensitivity testing of human lung cancer cell lines using the MTT assay.
Thirty human lung cancer cell lines were tested for chemosensitivity using the semi-automated, non-clonogenic MTT assay. The tumour cell lines came from three major categories of patients: untreated small cell lung cancer (SCLC); SCLC relapsing on chemotherapy; and non-SCLC predominantly from untreated patients. From these data IC50 values were derived for each drug in each cell line. While some inter-experimental variability was observed, the rank order of chemosensitivity of each cell line within this panel was significantly correlated between experiments. These results show that tumour cell lines derived from untreated small cell lung cancer patients were the most chemosensitive for adriamycin, melphalan, vincristine and VP16 compared to the other cell types. In addition, untreated SCLC was more sensitive than non-SCLC to BCNU and cis-platin, while vincristine was the only drug to which treated SCLC was more sensitive compared to the non-SCLC lines. In contrast, no significant differences between the lung cancer types were observed for vinblastine. Thus, this panel of lung cancer cells exhibited a drug sensitivity profile paralleling that observed in clinical practice. These results suggest that this lung cancer cell line panel in combination with a relatively simple but reproducible chemosensitivity assay, such as the MTT assay, has potential for the testing of drug combinations and evaluating new anti-cancer agents in vitro.
Antineoplastic Agents↗
Glutathione and related enzyme activity in human lung cancer cell lines.
Glutathione levels were measured in 30 human lung cancer lines. Lower levels were detected in cell lines derived from small cell lung cancer specimens compared to non-small cell lines (mean 42 vs. 130 nmol mg-1 protein, P = 0.005). However, no difference were detected between cell lines derived from previously untreated patients, compared to those derived from patients who had received chemotherapy. Non-small cell lines were found to have increased activity of 4 detoxification enzymes compared to small cell lines, although these differences did not reach statistical significance: glutathione transferase activity (69 vs. 36 units, P = 0.137), glutathione reductase (139 vs. 82 units, P = 0.05), gamma-glutamyl transpeptidase (9.39 vs. 3.03 units, P = 0.072) and superoxide dismutase (20 vs. 13.6 units, P = 0.137). As the cell lines exhibit a similar chemosensitivity pattern to that observed in clinical practice, these differences in glutathione and detoxification enzyme levels may prove to be important indicators of intrinsic drug resistance often seen in patients with non-small cell lung cancer.
Carcinoma, Non-Small-Cell Lung↗
Free radical formation and cell lysis induced by ultrasound in the presence of different rare gases.
The effect of varying the temperature of cavitation bubbles in aqueous solutions of different rare gases on free radical formation and shearing stress induced by ultrasound was investigated. After sonication with 50kHz ultrasound the yield of hydroxyl radicals was measured by spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide and the cell lysis of cultured mammalian cells was investigated. The hydroxyl radical yields were in the order Xe greater than Kr greater than Ar greater than Ne greater than He, in accord with the higher temperatures of the cavitation bubbles. However, cell lysis induced by shearing stress was the same for all of the rare gases, and independent of their thermal conductivity and the temperature of the cavitation bubbles.
Animals↗
Chemical modification of radiation and chemotherapy.
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Animals↗
Carbohydrate balance in competitive runners during successive days of intense training.
This study was designed to investigate the effect of intense training on muscle glycogen stores under conditions of controlled carbohydrate (CHO) intake. On two separate occasions, 10 highly trained distance runners increased their training load for 5 days (20 km/day, approximately 80% maximal O2 consumption) while eating a diet whose carbohydrate composition either equaled (EQ-CHO) or contained approximately 50% of the runner's estimated daily expenditure (LO-CHO). Total muscle glycogen levels were lower after the LO-CHO regimen. Photometric analysis of the glycogen content in individual fibers revealed that 27% type I and 17% type II fibers had optical densities less than 0.2 U after the LO-CHO regimen, whereas 7% type I and 0% type II were similarly depleted after the EQ-CHO diet. A linear relationship was observed between the histochemical and direct chemical analysis of muscle glycogen content. Treadmill O2 uptake measured at 185 and 238 m/min was higher during the LO-CHO than the EQ-CHO regimen. Ratings of perceived exertion were higher during the 238-m/min run for the LO-CHO regimen. After 3 days of rest, running economy and perception of effort returned to pretraining levels and muscle glycogen stores were approximately 85% of the pretraining values. Thus when CHO intake was only approximately 50% of the energy requirements there was a marked depletion of muscle glycogen stores, particularly in type I fibers, and a concomitant decrease in running economy and increased perception of fatigue.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Effects of repeated days of intensified training on muscle glycogen and swimming performance.
Twelve, highly trained male swimmers were studied before, during, and after 10 successive days of increased training in an attempt to determine the physical effects of training over-load. Their average training distance was increased from 4,266 to 8,970 m.d-1, while swimming intensity was maintained at 94% (SE +/- 2%) of their maximal oxygen uptake, resulting in an average caloric cost during training of 2,293 kcal.d-1 (+/- 74). As a result of the intensified training regimen, the swimmers experienced local muscular fatigue and difficulty in completing the training sessions. Nevertheless, their swimming power, sprinting (s.22.86 m-1), endurance (s.365.8 m-1) performance, aerobic capacity, and muscle (m. deltoid) citrate synthase were unchanged as a consequence of the 10-d training regimen. Four of the 12 swimmers were, however, unable to tolerate the heavier training demands, and were forced to swim at significantly slower (P less than 0.05) speeds during the training sessions. These men were found to have significantly reduced muscle glycogen values, which was the result of their abnormally low carbohydrate intake. The findings of this research suggest that some swimmers may experience chronic muscular fatigue as a result of their failure to ingest sufficient carbohydrate to match the energy demands of heavy training.
Adult↗
Physiological responses to successive days of intense training in competitive swimmers.
To examine the physiological responses to successive days of intense training, 12 male collegiate swimmers doubled their training distance (4,266 +/- 264 to 8,970 +/- 161 m.d-1) while maintaining the intensity at approximately 95% VO2max for 10 d. Blood samples were obtained pre-exercise and immediately and 5 min after a sub-maximal (approximately 95% VO2max) front crawl swim (365.8 m) on days 0, 5, and 11. Swim performance was assessed from a maximal front crawl swim (365.8 m), two maximal front crawl sprints (22.9 m), and a semi-tethered swim power test. No significant changes were observed in performance. Pre-exercise serum cortisol (17.5 +/- 1.5, 19.5 +/- 1.6, and 20.6 +/- 1.2 micrograms.dl-1 for days 0, 5, and 11, respectively) and creatine kinase (56.2 +/- 7.7, 93.1 +/- 10.1, and 119.0 +/- 23.1 U.l-1 for days 0, 5, and 11, respectively) values were significantly elevated (P less than 0.05) on days 5 and 11 compared to day 0. Resting plasma catecholamine concentrations were higher but not significantly different (P greater than 0.05) at the end of the training period. Measurements of hemoglobin and hematocrit indicated a relative increase of 11.4 +/- 2.7% (P less than 0.05) in estimated plasma volume during the training period. Resting blood glucose values were unaffected by the training regimen while small but significant decreases in resting blood lactate values (1.01 +/- 0.06, 0.85 +/- 0.06, and 0.86 +/- 0.06 mmol.l-1 for days 0, 5, and 11, respectively) were observed on days 5 and 11. Resting heart rate and systolic blood pressure were not affected by the increased training load.(ABSTRACT TRUNCATED AT 250 WORDS)
Blood Pressure↗