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At least 1,423 records · Page 79Linked to original sources
PubMed2004

Use of midlevel practitioners to achieve labor cost savings in the primary care practice of an MCO.

OBJECTIVE: To estimate the savings in labor costs per primary care visit that might be realized from increased use of physician assistants (PAs) and nurse practitioners (NPs) in the primary care practices of a managed care organization (MCO). STUDY SETTING/DATA SOURCES: Twenty-six capitated primary care practices of a group model MCO. Data on approximately two million visits provided by 206 practitioners were extracted from computerized visit records for 1997-2000. Computerized payroll ledgers were the source of annual labor costs per practice from 1997-2000. STUDY DESIGN: Likelihood of a visit attended by a PA/NP versus MD was modeled using logistic regression, with practice fixed effects, by department (adult medicine, pediatrics) and year. Parameter estimates and practice fixed effects from these regressions were used to predict the proportion of PA/NP visits per practice per year given a standard case mix. Least squares regressions, with practice fixed effects, were used to estimate the association of this standardized predicted proportion of PA/NP visits with average annual practitioner and total labor costs per visit, controlling for other practice characteristics. RESULTS: On average, PAs/NPs attended one in three adult medicine visits and one in five pediatric medicine visits. Likelihood of a PA/NP visit was significantly higher than average among patients presenting with minor acute illness (e.g., acute pharyngitis). In adult medicine, likelihood of a PA/NP visit was lower than average among older patients. Practitioner labor costs per visit and total labor costs per visit were lower (p<.01 and p=.08, respectively) among practices with greater use of PAs/NPs, standardized for case mix. CONCLUSIONS: Primary care practices that used more PAs/NPs in care delivery realized lower practitioner labor costs per visit than practices that used less. Future research should investigate the cost savings and cost-effectiveness potential of delivery designs that change staffing mix and division of labor among clinical disciplines.

Adolescent↗
PubMed2005

The administrative control system of substance abuse managed care.

OBJECTIVE: This article searches for the dimensions of the administrative structures in outpatient substance abuse managed care that control the behavior of agency providers. It also ascertains how these dimensions, and several financial mechanisms, affect key aspects of the providers services: the average number of sessions of care that are delivered, the rate of completion of care, and the (estimated) rate at which clients control their substance use. DATA SOURCES: The data were collected in 1999 for this investigation. STUDY DESIGN: These data come from a nationally representative, cross-sectional sample of individual contracts between outpatient drug treatment providers and the Behavioral Health Managed Care Organizations (BHMCOs) that are empowered to regulate the delivery of services. Provider responses are analyzed here. DATA COLLECTION METHODS: Factor analyses at a contract level examine the structural dimensions of the control system. Multivariate analyses at the same level rely on generalized linear models to predict the dependent variables by the structural dimensions and financial mechanisms. FINDINGS: The factor analyses suggest that there are six multiple variable structural dimensions. The multivariate analyses suggest that the dimension that mandates follow-up of discharged clients tends to relate to more sessions of care and perhaps a higher rate of service completion. Most other dimensions are found to relate to fewer sessions of care, lower rates of service completion, or lower rates of control of substance abuse. No structural dimension relates to all dependent variables. Financial mechanisms evince varying relations to the sessions of care. They rarely relate to the other dependent variables. CONCLUSION: The results generally suggest that providers, payers, or policymakers might affect service provision by selecting BHMCOs that stress particular structural dimensions and financial mechanisms. However, managed care contracts most heavily rely on structural dimensions that restrict treatment sessions and fail to predict superior client outcomes.

Ambulatory Care↗
PubMed2003

Setting priorities on waiting lists: point-count systems as linear models.

The Western Canada Waiting List Project (WCWL) is a federally funded initiative designed to develop tools for managing waiting lists. The principal tools developed by WCWL are point-count measures that assess the severity of patients' conditions and the extent of benefit expected from wait-listed services. Points are assigned according to the severity of patients' symptoms and clinical findings. Points on each factor are added and the total score is considered indicative of relative clinical urgency. Such point-count measures function as linear models from a statistical perspective. This paper describes the relevance of this functional relationship for the development and validation of priority criteria.

Activities of Daily Living↗
PubMed1998

Error rates in clinical radiotherapy.

PURPOSE: Error rates in clinical oncology are undergoing increasing scrutiny. The purpose of this study was to understand error frequency, error patterns, underlying causal links, consequences, and possible prevention strategies in clinical radiotherapy. PATIENTS AND METHODS: Treatment information, self-reported error documentation, and retrospective analyses of electronic treatment verification transcripts for 1,925 consecutive patients treated with a total of 93,332 individual radiotherapy fields were reviewed and analyzed. RESULTS: A total of 59 separate errors that affected 168 individual treatment fields were detected, which yielded a crude radiation delivery error rate of 0.18%. All 59 errors were judged to be level I (negligible chance of adverse medical outcome) with the most common error category being a minor treatment field block misplacement. A comprehensive quality assurance program and an electronic record-and-verify linear accelerator interlock system seem to have prevented the occurrence of many additional errors. However, nine of the 59 errors were directly related to the use of this system and generally involved the transposition of similar numbers within series of treatment coordinate data-sets. Overall, radiotherapy error rates favorably compare with reported error rates for pharmaceutical administration in large tertiary care hospitals. CONCLUSION: When modern automated error-minimization methods are used along with nonpunitive error reporting systems, clinical radiotherapy seems to be highly safe. Formal error analysis studies may allow the rational design of prevention strategies that are attuned to the frequency, seriousness, and antecedent causes of many classes of potential radiotherapy errors.

Humans↗
PubMed2000

Comparative evaluation of the degree of indomethacin crystallinity by chemoinfometrical Fourier-transformed [corrected] near-infrared spectroscopy and conventional powder X-ray diffractometry.

A chemoinfometrical method for evaluating the degree of crystallinity based on Fourier-transformed [corrected] near-infrared (FT-NIR) spectroscopy was established and compared with the conventional powder X-ray diffraction method. Powder X-ray diffraction profiles and FT-NIR spectra were recorded for 11 kinds of standard materials with various degrees of crystallinity obtained by physically mixing crystalline and amorphous indomethacin (IMC). Chemoinfometric analysis was performed on the FT-NIR spectral data sets by multiple linear regression (MLR) (MLR-Set-Up Search program). The crystalline and amorphous forms showed significant NIR spectral peaks. MLR analysis was performed based on normalized NIR spectra sets for standard samples of known crystallinity. A calibration equation was determined to minimize the root mean square error of prediction. The predicted crystallinity values were reproducible and had a smaller standard deviation. The values of crystallinity predicted by X-ray powder diffractometry and FT-NIR spectrometry suggested a satisfactory correlation between the 2 techniques. The results indicated that FT-NIR spectroscopy provides for an accurate quantitative analysis of crystallinity compared with conventional X-ray diffractometry.

Calorimetry, Differential Scanning↗
PubMed2002

Pharmacokinetics of ABT-773, a new semi-synthetic ketolide in neutropenic lung-infected mice: a population approach.

ABT-773 is an investigational ketolide antimicrobial agent with an in-vitro bactericidal activity against macrolide-susceptible and -resistant Streptococcus pneumoniae. The pharmacokinetics of this drug candidate were evaluated in lung-infected (108 CFU mL 1 starting inoculum) mice following a single dose (25, 50, 100 or 200 mg kg(-1)) oral administration as a solution in 10% of 95% ethanol and 90% of 0.1 M pH 6.5 phosphate buffer solution. Serum ABT-773 concentrations were measured using a validated HPLC assay with fluorescence detection (excitation at 324 nm and emission at 364 nm). Population pharmacokinetic analysis was performed using the NONMEM computer program. Results from data analysis showed non-linear pharmacokinetics of ABT-773, noted by the increases in half-life (3.1 to 27.2 h) and AUC/dose (23.7 to 149 mg h(-1) L(-1) mg(-1)), with doses from 25 to 200 mg kg(-1). A non-linear one-compartment model with parallel capacity-limited and linear first-order elimination best described the pharmacokinetics of ABT-773 in the mouse. The total volume of distribution was 0.316 L. The clearance for the linear first-order elimination was 0.0027 L h(-1). The Vm and Km were 0.0385 L h(-1) and 0.141 mg L(-1), respectively, for the capacity-limited elimination.

Administration, Oral↗
PubMedDate not supplied

Evaluation of the clinical utility of the ultrasensitive immunofluometric assay for growth hormone (GH) and of the cortisol secretory pattern in prediction of the linear growth response to treatment with GH.

OBJECTIVES: To evaluate the utility of an ultrasensitive IFMA for human 22 kDa GH in assessment of GH secretion and prediction of the linear growth response to exogenous GH. METHODS: Utilizing Delfia reagents supplied by Wallac-OY, an ultrasensitive IFMA for GH was established. Serum GH concentrations from 15 children/adolescents undergoing 24 hour GH secretory profiles with sampling at 20 minute intervals were analyzed by both IFMA and RIA. Cortisol values were also measured. Twelve children were later treated with GH. The 24 hour GH and cortisol secretory profiles were analyzed by the Cluster program and the relationships of these profiles to the linear growth response to exogenous GH determined. RESULTS: The sensitivity of the IFMA for GH relative to a zero standard was 0.005 ng/ml; intra-assay coefficients of variation ranged from 12% at a GH concentration of 0.005 ng/ml to 4% at 0.038 ng/ml; interassay coefficients of variation ranged from 34% at a GH concentration of 0.005 ng/ml to 10.5% at 2.7 ng/ml and to 2.7% at 12.7 ng/ml. Above assay sensitivity, there was good correlation between GH concentrations determined by IFMA and those by IRMA and RIA (r = 0.998 and 0.992 respectively). The number of GH secretory peaks identified by IFMA was significantly greater than that detected by RIA (10.6 +/- 3.2 [SD] vs 6.7 +/- 3.3/24 hours, p = 0.0001 by paired t-test). There were few significant relationships between any parameter of GH secretion measured by RIA or IFMA (peak GH pulse amplitude, percent increase in amplitude, area under the peak, interpeak interval) and the pretreatment growth rate, the growth velocity while receiving GH therapy, or the increment in growth rate during administration of GH. The number of GH secretory peaks determined by RIA correlated weakly with the pretreatment growth rate. There was no meaningful relationship between the serum concentrations of cortisol and GH-IFMA. Peak GH concentrations and nadir cortisol values were exactly coincident in 15.7% (25/159); 42.8% of nadir cortisol values coincided with or were within +/- 20 minutes of peak GH values (68/159). However, there was no relationship between the number of cortisol secretory peaks, the pooled 24 hour and nocturnal concentrations of cortisol and the pretreatment growth velocity, the growth rate or increment in growth velocity during administration of GH. CONCLUSIONS: Despite the increased sensitivity of the IFMA and its ability to detect pulsatile GH secretion heretofore unidentified, data from this GH assay were not useful in predicting first year growth rate during administration of GH. The secretory pattern of cortisol was not helpful in predicting the growth response to GH.

Adolescent↗
PubMed2004

Efficacy of a woman-focused intervention to reduce HIV risk and increase self-sufficiency among African American crack abusers.

OBJECTIVES: This study compares 3- and 6-month outcomes of a woman-focused HIV intervention for crack abusers, a revised National Institute on Drug Abuse standard intervention, and a control group. METHODS: Out-of-drug-treatment African American women (n = 620) who use crack participated in a randomized field experiment. Risk behavior, employment, and housing status were assessed with linear and logistic regression. RESULTS: All groups significantly reduced crack use and high-risk sex at each follow-up, but only woman-focused intervention participants consistently improved employment and housing status. Compared with control subjects at 6 months, woman-focused intervention participants were least likely to engage in unprotected sex; revised standard intervention women reported greatest reductions in crack use. CONCLUSIONS: A woman-focused intervention can successfully reduce risk and facilitate employment and housing and may effectively reduce the frequency of unprotected sex in the longer term.

Adult↗
PubMedDate not supplied

An empirical model of hyperopic shift with corticosteroid modulation and refractive power prediction after photorefractive keratectomy.

Data from a selected sample of 158 patients who received excimer laser photorefractive keratectomy (PRK) in our center and obtained a desirable refractive outcome at 6-months were analyzed retrospectively to establish an empirical model of refractive power after PRK. This model, generated by a computer-assisted regression program, is presented as a multivariate non-linear quadratic equation. Since the coefficients of each variable (attempted correction and postoperative days) are statistically significant, the estimated influence of the variables on the postoperative refraction from this regression model is reliable and consistent. Therefore, this model has been used to direct the use of corticosteroids for modulating post-PRK refraction. The predictability of this model has also been corroborated by separate data from 1-year follow up of PRK recipients. The recipients whose refraction at 6 months agree with the calculation from this model have obtained an excellent outcome; while those whose refractive outcome deviates from this model have gotten undesirable results.

Computer Simulation↗
PubMed2001

Evaluation of buffalo colostrum quality by estimation of enzyme activity levels.

A study to evaluate the value and potential use of colostral enzymes as markers for the evaluation of buffalo colostrum quality was conducted. The enzymes gamma-glutamyltransferase (GGT), lactic dehydrogenase (LDH), and alkaline phosphatase (ALP) in buffalo's colostrum were measured spectrophotometrically, and their activities were correlated with the gamma-globulin content. Gamma-globulin concentration was determined following the electrophoretic separation of the colostral proteins and quantified with a densitometer. Colostrum was obtained from 15 dams, soon after calving. Means, standard deviations, correlation coefficients, and degree of significance were calculated using the general linear model procedure of the Statistical Analysis Systems program. The activity of GGT in the colostrum was the highest, followed by LDH and ALP. A significant correlation (r = 0.86; P < 0.001) was seen between GGT and gamma-globulin concentration in the colostrum, supporting the suggestion of using this enzyme as a marker for the evaluation of colostrum quality.

Alkaline Phosphatase↗
PubMed2000

First among (UN) equals: assessing hospital performance using data envelopment analysis.

This article explores the use of Data Envelopment Analysis (DEA) as a comparative analytic tool to assess the relative effectiveness of competing hospitals. Building on previous research with DEA in hospital efficiency analysis, the authors extend the earlier technical efficiency-based DEA models to include qualitative outcome measures. Data from hospitals in a regional competitive health care market in South Florida are assessed using this new DEA model.

Benchmarking↗
PubMed2004

Pharmacokinetics of magnesium lithospermate B after intravenous administration in beagle dogs.

AIM: To develop a specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the pharmacokinetic study of magnesium lithospermate B (MLB), and study the pharmacokinetics of MLB after i.v. administration in beagle dogs. METHODS: Each beagle dog was iv administered MLB 3, 6, and 12 mg/kg random. The serum drug concentration was determined by specific liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays. The pharmacokinetic parameters were calculated by Drug and Statistics version 1.0 program. RESULTS: The calibration curve for MLB was linear over a range of 16-4096 microg/L with coefficients of correlation >0.999. The intra- and inter-day precisions (CV) of analysis were <10 %, and accuracy ranged from 90 % to 113 %. After i.v. administration of MLB at the doses of 3, 6, and 12 mg/kg, the C(0) values for MLB were estimated to be of 24, 47, and 107 mg/L, respectively. The AUC increased with the increasing doses for iv administration, and the mean AUC(0-t) values were 109.3, 247.9, and 582.4 mg x min x L(-1), respectively. MLB was distributed and eliminated quickly from central compartment, the mean T(1/2alpha) values for MLB at doses of 3, 6, 12 mg/kg were 2.2, 2.7, and 2.9 min, and the mean T(1/2beta) values were 43, 42, and 42 min, respectively. CONCLUSION: This LC-MS/MS method is rapid, sensitive, and specific for the pharmacokinetic study of MLB. The kinetic process of MLB in beagle dogs in vivo was best fitted to a two-compartment model. For i.v. administration, the pharmacokinetic parameters of C(0) and AUC have good linearity among the doses, and MLB was distributed and eliminated quickly in beagle dogs.

Animals↗
PubMedDate not supplied

[Mathematical modelling of perorally induced immunological tolerance].

A mathematical model of the mechanism of development of orally induced immunologic tolerance has been suggested. The model presents a system of differential non-linear equations, and it is realized as a program in FORTRAN. The model describes primary and secondary immune responses, reflects the main features of the immune system response to antigen intake with food. The immune system model response to varying doses and frequency of the antigen intake with food has been studied. It has been established that repeated administration of small doses of the food antigen leads to a deeper tolerance due to lower stimulation of the immune system. The existence of optimal tolerogenic doses of the food antigen has been proved. Qualitative changes in the immune system response to the food antigen have been recorded in case of increased permeability of the intestinal wall.

Administration, Oral↗
PubMed1978

Shunt quantification by mathematical analysis of indicator dilution curves.

Mathematical models are presented for describing and analyzing indicator dilution curves recorded in patients with intracardiac and great vessel shunts. The models treat individual segments of the circulation as linear system blocks, each having, at its output, a characteristic time response to a rapid injection of indicator at its input. These blocks are combined in feedback and feed-forward configurations to simulate left-to-right, right-to-left, and bidirectional shunts. A shunt analysis algorithm, using discrete analogs of the linear system models, was implemented in a computer program and used to analyze thermodilution curves recorded in patients with congenital heart defects. Results are presented comparing shunt fractions obtained from thermodilution curve analyses with oximetrically determined values in 20 patients. Comparing left-to-right shunts measured by the two methods, the mean systematic difference was 0.7% of pulmonary flow and the standard deviation was 7.6% of pulmonary flow. Statistical validation of the bidirectional shunt method will require acquisition and analysis of more data; however, reasonable shunt fractions were computed in five cases studied and good agreement with oximetric determinations was obtained in two cases where complete oximetric data were available.

Adolescent↗
PubMed2006

Evaluation of an interactive case simulation system in dermatology and venereology for medical students.

BACKGROUND: Most of the many computer resources used in clinical teaching of dermatology and venereology for medical undergraduates are information-oriented and focus mostly on finding a "correct" multiple-choice alternative or free-text answer. We wanted to create an interactive computer program, which facilitates not only factual recall but also clinical reasoning. METHODS: Through continuous interaction with students, a new computerised interactive case simulation system, NUDOV, was developed. It is based on authentic cases and contains images of real patients, actors and healthcare providers. The student selects a patient and proposes questions for medical history, examines the skin, and suggests investigations, diagnosis, differential diagnoses and further management. Feedback is given by comparing the user's own suggestions with those of a specialist. In addition, a log file of the student's actions is recorded. The program includes a large number of images, video clips and Internet links. It was evaluated with a student questionnaire and by randomising medical students to conventional teaching (n = 85) or conventional teaching plus NUDOV (n = 31) and comparing the results of the two groups in a final written examination. RESULTS: The questionnaire showed that 90% of the NUDOV students stated that the program facilitated their learning to a large/very large extent, and 71% reported that extensive working with authentic computerised cases made it easier to understand and learn about diseases and their management. The layout, user-friendliness and feedback concept were judged as good/very good by 87%, 97%, and 100%, respectively. Log files revealed that the students, in general, worked with each case for 60-90 min. However, the intervention group did not score significantly better than the control group in the written examination. CONCLUSION: We created a computerised case simulation program allowing students to manage patients in a non-linear format supporting the clinical reasoning process. The student gets feedback through comparison with a specialist, eliminating the need for external scoring or correction. The model also permits discussion of case processing, since all transactions are stored in a log file. The program was highly appreciated by the students, but did not significantly improve their performance in the written final examination.

Adult↗
PubMed1999

HIV risk reduction in outpatient drug abuse treatment: individual and geographic differences.

In the national Drug Abuse Treatment Outcome Studies (DATOS), many clients in outpatient methadone treatment (OMT) and outpatient drug-free (ODF) modalities were admitted with multiple sex and needle-risk behaviors, but they reduced these risks significantly during treatment. Using hierarchical linear model regression analysis, we examined client and treatment program characteristics as predictors of initial risk levels and of reductions over time. Clients who used cocaine frequently before treatment or had antisocial personality disorder entered treatment with elevated risks. In both modalities, cocaine users reduced risky behaviors significantly, but antisocial clients did so only in OMT. Treatment programs located in cities with higher prevalence rates of HIV/AIDS admitted clients with lower baseline levels of risk behavior than found in other cities. OMT programs in lower prevalence cities achieved higher rates of risk reduction than programs in higher prevalence cities. Reduction of sex and needle risks in both the OMT and ODF modalities indicates the importance of outpatient drug abuse treatment to national HIV prevention policy.

Adult↗