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Biomedical subjects

M E Miller

Publications and source records attributed to M E Miller.

At least 127 records · Page 7Linked to original sources

Decisions without consequences: cost control and access in state Medicaid programs.

States have implemented a number of strategies to provide services, pay providers, and control Medicaid spending. We test the effects of some differences in state Medicaid policies on program enrollees' access to and use of health care services. Logistic and OLS regression analyses of cross-sectional data indicate that these policies exert significant influences on enrollees' access to health services but have a weaker direct effect on their use of them. However, we find evidence that utilization is affected indirectly (through increased access) by state policy decisions. Somewhat surprisingly, Medicaid policies designed to contain costs by limiting utilization appear to affect neither access nor utilization. Medicaid enrollees have greater access to a private physician in states with higher physician reimbursement and additional Medicare insurance for their enrollees. Other nonpolicy variables with pronounced impacts on access to private office physicians include race and the availability of private insurance.

Cost Control↗

Medicare hospital outpatient services and costs: implications for prospective payment.

Medicare expenditures of hospital outpatient department (HOPD) services are growing rapidly, prompting congressional interest in a prospective payment system. In this article, the authors identify frequently provided services and examine service volume and charges in the HOPD. Relatively few services drive Medicare HOPD spending, and volume is dominated by visits, imaging and laboratory tests, whereas surgery accounts for a large proportion of charges. Hospital-level variations in charges, costs, case mix, and outliers are also explored. There is substantial variation in charges and costs across hospital types. However, after case-mix adjustment, all hospital types have average costs within 6 percent of the national average.

Ambulatory Surgical Procedures↗

Physician charges in the hospital. Exploring episodes of care for controlling volume growth.

Medicare physician payments are growing rapidly. At least 40% of the annual growth is due to volume increases. Reforms passed in 1989 include volume performance standards that attempt to control volume by linking future physician fee increases to volume growth. There is concern that defining the entire nation as the risk pool will result in an unworkable volume performance standard. One way to improve incentives is to create a separate volume performance standard for in-hospital physician services, define bundles of services related to the hospital stay, and place the medical staff of the hospital at risk for volume growth. To forestall the unbundling of services outside the stay, windows could be defined around the stay. This study reports physician services during the stay and in windows around the stay. In so doing, the study creates the knowledge base necessary to design better volume control policies and judge among alternative window definitions. Using 1987 data, this study presents average physician charges by type of service during: 1) the hospital stay; and 2) 1-month windows before and after the stay. For all admissions, 85% of charges occur during the stay and 15% occur during the windows (windows for surgical admissions and medical admissions are 9% and 23%, respectively). Pre- and postwindows are roughly symmetrical and average charges per day gradually increase before the admission and decline after discharge. A small physician panel commented on the clinical appropriateness of the one month windows. The panel indicates that defining in-hospital episodes of physician care is feasible.

Ambulatory Surgical Procedures↗

Validation techniques for logistic regression models.

This paper presents a comprehensive approach to the validation of logistic prediction models. It reviews measures of overall goodness-of-fit, and indices of calibration and refinement. Using a model-based approach developed by Cox, we adapt logistic regression diagnostic techniques for use in model validation. This allows identification of problematic predictor variables in the prediction model as well as influential observations in the validation data that adversely affect the fit of the model. In appropriate situations, recommendations are made for correction of models that provide poor fit.

Benzothiadiazines↗

Phase II trial of high-dose cisplatin plus etoposide plus vinblastine in non-small-cell lung cancer. A Hoosier Oncology Group study.

Fifty-one patients with advanced non-small-cell lung cancer were treated on a Hoosier Oncology Group protocol with an aggressive, high-dose cisplatin combination chemotherapy regimen. All patients had a Karnofsky performance status of 80% or higher and had no prior chemotherapy. The drug regimen consisted of cisplatin 30 mg/m2 days one through five, etoposide 40 mg/m2 days one through five, and vinblastine 5 mg/m2 day one. Therapy was given every three weeks for a total of three courses. Forty-five patients were evaluable for response and an objective response was seen in 15 patients (33%) with only one complete responder. The median duration of response was 16.5 weeks. The median survival for the entire group was 29.0 weeks. Toxicity was moderately severe with two treatment-related deaths (4%). Despite an aggressive chemotherapy regimen in a favorable patient population, there was no obvious evidence of a major therapeutic value.

Antineoplastic Combined Chemotherapy Protocols↗

Sexually transmissible diseases in injecting drug users.

Self-reported histories of sexually transmissible diseases (STDs) and HIV serostatus were investigated as part of a study of HIV risk behaviour in a sample of 1245 Syndey injecting drug users (IDUs) (mean age 27.5 years) both in and out of treatment. A high lifetime prevalence of STDs was reported in both men and women. For male IDUs, the lowest reported lifetime prevalence of STDs was in heterosexuals, with bisexuals intermediate and homosexuals reporting the highest prevalence. HIV seroprevalence followed the same pattern. For women, bisexuals had the highest reported STD history, heterosexual women were intermediate and homosexual women reported the lowest prevalence. Over one third of the bisexual women reported having been involved in prostitution. These data indicate that over one third of IDU men and over half of IDU women reported at least one STD in their lifetime. The high lifetime prevalence of STDs in IDUs indicates that this group is at increased risk of sexual transmission of HIV, given the importance of STDs as a cofactor. Reducing the prevalence of STDs in IDUs is a possible additional strategy to diminish the spread of HIV among IDUs and from them to non-IDU sexual contacts.

Adult↗

Megaloblastic hematopoiesis in vitro. Interaction of anti-folate receptor antibodies with hematopoietic progenitor cells leads to a proliferative response independent of megaloblastic changes.

We tested the hypothesis that anti-placental folate receptor (PFR) antiserum-mediated effects on hematopoietic progenitor cells in vitro of increased cell proliferation and megaloblastic morphology were independent responses. We determined that (a) purified IgG from anti-PFR antiserum reacted with purified apo- and holo-PFR and specifically immunoprecipitated a single (44-kD) iodinated moiety on cell surfaces of low density mononuclear cells (LDMNC); (b) when retained in culture during in vitro hematopoiesis, anti-PFR IgG (in contrast to PFR-neutralized anti-PFR IgG and nonimmune IgG) consistently led to increased cloning efficiency of colony forming unit-erythroid (CFU-E), burst forming unit-E (BFU-E), CFU-granulocyte macrophage (CFU-GM), and CFU-GEM megakaryocyte (CFU-GEMM), and objectively defined megaloblastic changes in orthochromatic normoblasts from CFU-E- and BFU-E-derived colonies; (c) when anti-PFR antiserum was removed after initial (less than 1 h) incubation with LDMNC, a cell proliferation response was induced, but megaloblastic changes were not evident. (d) Conversely, delay at 4 degrees C for 24 h before long-term plating with antiserum resulted in megaloblastosis without increased cell proliferation; (e) however, 500-fold molar excess extracellular folate concentrations completely abrogated the expected anti-PFR antiserum-induced megaloblastic changes, without altering cell proliferative responses. Thus, although cell proliferative and megaloblastic changes are induced after short-term and prolonged interaction of antibody with folate receptors on hematopoietic progenitors, respectively, they are independent effects.

Animals↗

Randomized study of cisplatin dose intensity in poor-risk germ cell tumors: a Southeastern Cancer Study Group and Southwest Oncology Group protocol.

Between 1984 and 1989, 159 patients presenting with advanced germ cell cancer were entered on a randomized clinical trial comparing the efficacy and toxicity of etoposide and bleomycin and either standard-dose cisplatin (20 mg/m2 daily for 5 days) or high-dose cisplatin (40 mg/m2 daily for 5 days). Of the 159 patients, 153 were assessable for toxicity and response. As expected, patients receiving the high-dose cisplatin regimen experienced significantly more neurotoxicity, ototoxicity, nausea and vomiting, and myelo-suppression. Four patients (3%) died related to therapy. Despite the toxicity encountered, dose intensity was maintained. Overall, 84% of patients in the high-dose arm received 80% or more of the projected dose of cisplatin, etoposide, and bleomycin; and 90% of patients on the standard-dose arm received 80% or more of the projected dose. Of the 76 eligible patients randomized to receive the high-dose cisplatin regimen, 52 (68%) became disease-free with chemotherapy alone or with subsequent resection of residual teratoma or cancer. Of the 77 patients randomized to the standard-dose arm, 56 (73%) became disease-free with chemotherapy alone or with surgery. Median follow-up is now 24 months. Eleven patients (three high-dose and eight standard-dose) relapsed from disease-free status. Overall, 74% of patients receiving the high-dose cisplatin regimen are alive, and 63% are continuously free of disease. Of the patients receiving the standard-dose cisplatin regimen, 74% are alive, and 61% are continuously free of disease. This randomized prospective trial in advanced germ cell cancer achieved dose intensity of the most active single agent in this disease. This dose intensity did not translate into an improved survival or cure. We conclude that dose escalation of cisplatin beyond standard doses results in excess toxicity with no accompanying therapeutic benefit.

Adolescent↗

Practice randomization and clinical research. The Indiana experience.

Thoughtful preparation of a research laboratory is an early step in designing a program for scientific investigation. The Division of General Internal Medicine at Indiana University has maintained a "laboratory" for outpatient clinical investigation for more than 15 years. In this report, we describe the structure and function of the General Medicine Practice in the Regenstrief Health Center on the campus of the Indiana University School of Medicine in Indianapolis. Specifically, we discuss the ongoing random allocation of subjects, the local resources for data management and tracking of patients' use of clinical services, and how combining this information system into a randomized primary care system has fostered successful ventures in clinical investigation.

Health Services Research↗

Scapular fractures. Analysis of 113 cases.

Scapular fractures have been the subject of study since Desault's treatise of 1805, but few large-scale studies have been completed with long-term follow-up evaluation of displaced scapular neck and spine fractures. This series of 148 fractures in 116 scapulae (113 patients) appears to be the largest ever reported and the only one with a follow-up study of a significant group (24 patients). Significant disability was found in patients with displaced scapular spine and neck fractures: (1) pain at rest in 50%-100%, (2) weakness with exertion in 40%-60%, and (3) pain with exertion in 20%-66%. Based on these findings, the indications for operative management should be expanded to include displaced scapular neck and spine fractures. Using extensile exposure through a posterior Judet incision, rigid internal fixation, and early motion, results in eight cases were excellent. All patients recovered at least 85 degrees of glenohumeral abduction, normal scapulothoracic motion, and none had resting pain, night pain, or pain with abduction. The minimum follow-up study period was 15 months.

Adolescent↗

A herald bleed: a case of aortoesophageal fistula and a review of the literature.

Survival in AEF is rare because the diagnosis of this uncommon entity is not always suspected, and few patients survive despite aggressive but often late intervention. We present this case to increase awareness of AEF, which although rare, does occur and should be suspected in any patient who presents with midthoracic pain or dysphagia and herald bleeding.

Aged↗

Generalized variance component models for clustered categorical response variables.

A generalized variance component model is proposed for the analysis of a categorical response variable with extra-multinomial variation. Categorical data obtained from research designs such as randomized multicenter clinical trials or complex sample surveys with clustering frequently exhibit extra-variation resulting from intracluster correlation. General correlation patterns are accounted for by utilizing a mixed-effects modelling approach, estimating the cluster variance components through the method of moments and modelling functions of the observed proportions through the use of estimating equations. A flexible set of assumptions characterizing the underlying covariance structure for the proportions can be accommodated. The importance of accounting for extra-variation when performing hypothesis tests is highlighted with an application to data from a multi-investigator clinical trial.

Analysis of Variance↗

Enhanced stimulation of human bone marrow macrophage colony formation in vitro by recombinant human macrophage colony-stimulating factor in agarose medium and at low oxygen tension.

Recombinant (r) and natural human (h) macrophage colony-stimulating factor (M-CSF, CSF-1) have been considered poor stimulators of macrophage progenitor cells present in human marrow, although they are potent stimulators of these cells in mouse marrow. We compared the growth characteristics of rhM-CSF-responsive human macrophage progenitor cells placed in semisolid agarose or agar culture medium and incubated for 14 days at ambient (approximately 20%) or lowered (5%) O2 tension. By itself, rhM-CSF was found to be a good stimulator of macrophage colony formation by human bone marrow cells cultured in agarose but not in agar; this growth was enhanced by incubation at 5% O2. Maximal numbers (up to 115/10(5) nonadherent low density cells plated) of macrophage colonies (50 to greater than 500 cells per colony) were stimulated by 500 to 1,000 units rhM-CSF/mL, with 1/2 maximal numbers stimulated by 250 to 500 units/mL. With agarose as the support medium, rhM-CSF was two- to fourfold more active on mouse than on human macrophage colony formation, in contrast to previous reports of 10- to 100-fold greater activity when agar was used as the support medium. Using nonadherent low density T lymphocyte-depleted human bone marrow cells growing in agarose at 5% O2, greater than additive effects on colony formation were observed when 31 to 500 units rhM-CSF were used in combination with either 10 ng rh interleukin-1 alpha (IL-1 alpha), 20, or 200 units rh granulocyte-macrophage (GM)-CSF or rhG-CSF. The agarose assay system should be useful for evaluating factors regulating the proliferation of human macrophage progenitor cells in vitro and during clinical trials with rhM-CSF.

Agar↗

The effect on test ordering of informing physicians of the charges for outpatient diagnostic tests.

We studied the effect of informing physicians of the charges for outpatient diagnostic tests on their ordering of such tests in an academic primary care medical practice. All tests were ordered at microcomputer workstations by 121 physicians. For half (the intervention group), the charge for the test being ordered and the total charge for tests for that patient on that day were displayed on the computer screen. The remaining physicians (control group) also used the computers but received no message about charges. The primary outcomes measured were the number of tests ordered and the charges for tests per patient visit. In the 14 weeks before the study, the number of tests ordered and the average charge for tests per patient visit were similar for the intervention and control groups. During the 26-week intervention period, the physicians in the intervention group ordered 14 percent fewer tests per patient visit than did those in the control group (P less than 0.005), and the charges for tests were 13 percent ($6.68 per visit) lower (P less than 0.05). The differences were greater for scheduled visits (17 percent fewer tests and 15 percent lower charges for the intervention group; P less than 0.01) than for unscheduled (urgent) visits (11 percent fewer tests and 10 percent lower charges; P greater than 0.3). During the 19 weeks after the intervention ended, the number of tests ordered by the physicians in the intervention group was only 7.7 percent lower than the number ordered by the physicians in the control group, and the charges for tests were only 3.5 percent lower (P greater than 0.3). Three measures of possible adverse outcomes--number of hospitalizations, emergency room visits, and outpatient visits during the study period and the following six months--were similar for the patients seen by the physicians in both groups. We conclude that displaying the charges for diagnostic tests significantly reduced the number and cost of tests ordered, especially for patients with scheduled visits. The effects of this intervention did not persist after it was discontinued.

Ambulatory Care↗

Primary mediastinal nonseminomatous germ cell tumors. A modern single institution experience.

Between 1976 and 1988, 31 patients with mediastinal nonseminomatous germ cell tumors (MNGCT) received initial cisplatin-based chemotherapy of uniform intensity. Eighteen of these patients (58%) obtained disease-free status; 11 with chemotherapy alone and seven with adjunctive surgery. Eleven have remained continuously free of disease. Two have had recurrence of teratoma and are disease-free after resection of teratoma at 12+ and 68+ months. Three patients developed recurrence of germ cell tumor. Three patients developed a hematologic malignancy. Of the 18 patients who obtained disease-free status, 15 remain alive and disease-free. Overall, 13 of the 31 patients and 24 other patients received salvage chemotherapy at Indiana University, Indianapolis, Indiana. Of these 37 patients, six obtained a disease-free status and four (11%) remain alive at 13+, 56+, 78+, and 122+ months, respectively. This series represents the largest series of patients with MNGCT ever reported. Analysis of these data and results from other recent series suggest that approximately 50% of patients with MNGCT will be cured with modern, intense cisplatin-based chemotherapy coupled with adjunctive surgery if needed.

Adult↗

Effect of omental, intercostal, and internal mammary artery pedicle wraps on bronchial healing.

Bronchial transection and devascularization is necessary in the course of sleeve resection or lung transplantation, leaving distal bronchial segments ischemic and subject to stricture or dehiscence. Thirty mongrel dogs underwent left lung autotransplantation. The bronchial anastomosis was wrapped with omentum (n = 9), intercostal muscle pedicle (n = 9), or internal mammary artery pedicle grafts (n = 6). Six control animals underwent bronchial anastomosis without an external wrap. Bronchial revascularization by capillary ingrowth from the pedicle to the bronchial submucosal plexus was demonstrated with all three types of vascular pedicle grafts; however, more consistent and confluent vascular ingrowth was provided by internal mammary artery pedicle grafts. Additionally, the bronchial anastomotic cross-sectional area was significantly better in the internal mammary artery group (84.5 +/- 3.3) as compared with that of the omental (68.4 +/- 8.3), intercostal muscle (66.9 +/- 10.9), or control groups (70.2 +/- 7.6). An internal mammary artery pedicle graft and the presence of dense confluent submucosal vascular ingrowth from any pedicle graft were independently predictive (p less than 0.05) of minimizing bronchial anastomotic narrowing. These data are consistent with previous findings suggesting that omental and intercostal muscle pedicle grafts promote early bronchial revascularization; moreover, the data demonstrate the superiority of an internal mammary artery pedicle graft to provide submucosal vascular ingrowth and to minimize anastomotic stenosis.

Anastomosis, Surgical↗