PubMed Health⌕ Search

Biomedical subjects

R C McDonald

Publications and source records attributed to R C McDonald.

At least 19 recordsLinked to original sources
PubMed1999

Mailed reminders for area-wide influenza immunization: a randomized controlled trial.

OBJECTIVE: To determine if mailed reminders would increase area-wide influenza immunization for persons aged 65 and older. DESIGN: A randomized, controlled trial. SETTING: Ten counties in Indiana. PARTICIPANTS: Using a Medicare database, 10,000 subjects were selected randomly from 10 counties in Indiana and randomized for the study. Using pre-established criteria, 4503 persons in the control group and 4508 in the intervention group were eligible for study. INTERVENTION: Intervention subjects received mailed reminders during the immunization season of 1995. MEASUREMENTS: Data from mailed surveys, Medicare claims, and phone calls were used to determine immunization rates. RESULTS: Of those surveyed who received immunization, only 63.4% filed a Medicare claim. Immunization rates were high in both groups but higher in the intervention group, 69.0% versus 64.2%. Age, presence of lung disease, assignment to the intervention group, presence of heart disease, and an age-sex interaction term were significantly and independently related to immunization. CONCLUSIONS: The Healthy People Year 2000 goal (60% immunization for persons 65 and older) was exceeded in this population. Medicare claims data do not reflect immunization rates accurately. Mailed reminders, an inexpensive intervention, increased immunization rates area-wide and have potential for cost savings.

Age Factors↗
PubMed1998

Diabetes and the promise of managed care.

The term managed care has a positive connotation to many people and a negative connotation to others. It implies a systematic approach to the provision of care supported by a managed care organization, the underlying values of which are efficiency in care delivery and continuous health improvement of the population being served. The recent advances in knowledge surrounding the treatment of diabetes, the codification of these advances into treatment guidelines, and the significant gap between recommended and real-world treatment patterns all suggest that there is an opportunity for managed care organizations to play a beneficial role in improving the treatment of people with diabetes. Typical strategies used by managed care organizations include dissemination of treatment guidelines and information feedback to providers and patients to suggest diagnostic measures or therapeutic interventions that should be repeated with regularity to maintain or improve the health of people with diabetes. Improvements in population-level measurement of health care quality will increase the focus on preventable long-term complications of diabetes and other chronic diseases and may establish increasingly quantitative quality metrics that should improve real-world treatment patterns. Models exist for a multifaceted approach to improve the care of people with diabetes through such mechanisms; this article reviews the experience of one health plan with such undertakings.

Blood Glucose↗
PubMed1997

Diabetic ketoacidosis charges relative to medical charges of adult patients with type I diabetes.

OBJECTIVE: To determine the medical charges for treating diabetic ketoacidosis (DKA) episodes relative to direct medical care charges of adult patients with type I diabetes. RESEARCH DESIGN AND METHODS: Using data from an electronic medical record system, we identified adult patients with type I diabetes who had received inpatient or outpatient care on at least two occasions between 1 January 1993 and 30 June 1994. Resources and charges for hospitalizations, emergency room visits, outpatient visits, and pharmaceuticals were recorded during this period. One additional year of information was collected to assess the resources and charges associated with multiple DKA episodes. RESULTS: A total of 200 patients were identified, of whom 72 (36.0%) experienced a total of 161 DKA episodes. The direct medical care charges associated with DKA episodes represented 28.1% of the direct medical care charges for the cohort of patients with type I diabetes. The average charge per DKA episode was $6,444. The estimated annual medical care charge for each patient was $7,855 ($13,096 per patient experiencing a DKA episode versus $4,907 per patient not experiencing an episode). Multiple DKA episodes were experienced by 24 (12.0%) of the study patients and accounted for 55.6% of the direct medical care charges for these patients. CONCLUSIONS: DKA episodes represented more than $1 of every $4 spent on direct medical care for adult patients with type I diabetes and $1 of every $2 in those patients experiencing multiple episodes. Interventions that are capable of even a modest reduction in the number of DKA episodes could produce substantial cost savings in a health care system and could be particularly cost-effective in adult patients with recurrent DKA.

Adult↗
PubMed1996

Economic value of gemcitabine compared to cisplatin and etoposide in non-small cell lung cancer.

Although chemotherapy costs have not been highlighted traditionally, there is increasing pressure to demonstrate the value of new treatments within the health care budget. Pharmaceutical companies are assessing the economic value of their products before launch. Gemcitabine is a nucleoside analogue developed for use in solid tumours. The purpose of this model was to investigate the clinical outcomes and potential cost savings for gemcitabine used as monotherapy compared to cisplatin and etoposide combination therapy in late stage non-small cell lung cancer (NSCLC), in a palliative (as opposed to aggressive) chemotherapy setting. Gemcitabine treatment data were taken from a large NSCLC study and data from retrospective chart reviews identified through the National Oncology Data Base. The model population and effectiveness of the two regimens were judged to be similar, except for baseline performance status. If drug costs were not included, the probability distribution resulting from the simulation showed median cost savings per cycle ranging from $US 1504 to $US 7425, with a medium value of $US 2154. The model suggested that gemcitabine would result in cost savings per cycle more than 90% of the time. Outpatient versus inpatient drug administrations accounted for the majority of potential cost savings. Most of the remaining cost savings were attributable to the difference in febrile neutropenia and antiemetic use. This economic model showed susbstantial savings if gemcitabine was used instead of cisplatin and etoposide combination therapy in the United States' community care setting. Some savings would be realized even if the location of treatment for both regimens was mostly outpatient. Assessment of the product's economic value before launch has assisted in our understanding of the potential areas of cost savings for gemcitabine and has guided us in the design of prospective randomized studies which included pharmacoeconomic endpoints.

Antimetabolites, Antineoplastic↗
PubMed1994

Screening surgeons for HIV infection: assessment of a potential public health program.

OBJECTIVE: To develop a model to assess the impact of a program of testing surgeons for human immunodeficiency virus (HIV) on the risk of HIV acquisition by their patients. DESIGN: A Monte Carlo simulation model of physician-to-patient transmission of human immunodeficiency virus (HIV) infection using three different rates of physician-to-patient transmission per percutaneous exposure event (0.15%, 0.3%, 0.6%). Data from the model were developed from a review of the medical literature and from subjective probability estimates when data were not available. We used this model to estimate on a national basis the annual number of cases of HIV transmission from surgeons to patients with and without surgeon testing and practice limitations. RESULTS: The annual number of transmitted cases would range from 0.5 (+/- 0.3), assuming a surgeon HIV prevalence of 0.1% and a surgeon-to-patient transmission rate of 0.15%, to 36.9 (+/- 11.6), assuming a surgeon HIV prevalence of 2% and a surgeon-to-patient transmission rate of 0.6%. After one screening cycle, a mandatory screening program would be expected to reduce the annual transmissions to 0.05 (+/- 0.03) and 3.1 (+/- 1.1), respectively. CONCLUSION: Patients are at low risk of acquiring HIV infection from an infected physician during an invasive procedure. The potential costs of such a program extended beyond the costs of testing and counseling. In communities with high HIV prevalence, screening surgeons and limiting their practices may decrease patient access to care. A disability insurance program also would be required to protect surgeons and trainees performing invasive procedures. Screening surgeons for HIV infection would be a costly undertaking that would reduce but not completely eliminate this risk.

AIDS Serodiagnosis↗
PubMed1989

Tuberculosis epidemic among hospital personnel.

Six employees of the emergency department at Parkland Memorial Hospital developed active tuberculosis in 1983-1984. Five of the cases occurred four to 12 months after exposure to the index case, a patient with severe cavitary tuberculosis seen in the emergency department in April 1983. One resident physician developed cavitary disease after exposure to this patient. An additional employee case may have resulted from transmission from one of the initial employee cases. One immunocompromised patient may have acquired tuberculosis as a result of exposure to the index case. In addition, the tuberculin skin tests of at least 47 employees exposed to the index case converted from negative to positive. Of 112 previously tuberculin-negative emergency department employees who were tested in October 1983, 16 developed positive skin tests, including the 5 employees with active disease. Fifteen of these new positives had worked on April 7, 1983, while the index case was in the emergency department (X2 = 20.6, P less than 0.001). Factors related to the genesis of the epidemic included the disease characteristics in the index case and the recirculation of air in the emergency department. This investigation indicates that city-county hospital emergency department employees should be screened at least twice a year for evidence of tuberculosis and that the employee health services of such hospitals should regard the surveillance of tuberculosis infection among personnel at a high-priority level.

Aged↗
PubMed1988

The persistence of Shigella flexneri in the United States: increasing role of adult males.

The annual reported isolation rate of Shigella flexneri decreased from 1964 to 1973, but has remained constant since then at 1 per 100,000. Between 1975 and 1985, the median age of males from whom S. flexneri was isolated rose from 5 to 26 years. During this time, the isolation rate of S. flexneri rose more than five-fold among men, did not change in adult women, and decreased in children. By 1985, 23 per cent of reported S. flexneri isolates came from men aged 20-49. Increased male homosexual transmission of S. flexneri is a possible explanation for these findings.

Adult↗
PubMed1987

Massive outbreak of antimicrobial-resistant salmonellosis traced to pasteurized milk.

Two waves of antimicrobial-resistant Salmonella typhimurium infections in Illinois totaling over 16 000 culture-confirmed cases were traced to two brands of pasteurized 2% milk produced by a single dairy plant. Salmonellosis was associated with taking antimicrobials before onset of illness. Two surveys to determine the number of persons who were actually affected yielded estimates of 168 791 and 197 581 persons, making this the largest outbreak of salmonellosis ever identified in the United States. The epidemic strain was easily identified because it had a rare antimicrobial resistance pattern and a highly unusual plasmid profile; study of stored isolates showed it had caused clusters of salmonellosis during the previous ten months that may have been related to the same plant, suggesting that the strain had persisted in the plant and repeatedly contaminated milk after pasteurization.

Adolescent↗
PubMed1979

Small angle X-ray scattering of dimeric yeast hexokinase in solution.

Small angle x-ray scattering measurements on dimeric yeast hexokinase B at pH 5.5 in acetate buffer yield a radius of gyration of 31.28 +/- 0.23 angstrom. This measured value is comparable to the radius of gyration of 31.5 angstrom calculated from the refined coordinates of the dimer in the BII crystal form. The hexokinase dimer found in the BI crystal form has a radius of gyration of 42 angstrom calculated from the atomic coordinates. Thus, the measured radius of gyration is consistent with the BII dimer being the predominant species in solution and rules out the existence of the BI dimer as a major species under these conditions.

Hexokinase↗
PubMed1979

Yeast hexokinase in solution exhibits a large conformational change upon binding glucose or glucose 6-phosphate.

Using small-angle X-ray scattering from solutions of yeast hexokinase, we have measured the radii of gyration of the monomeric B isozyme and its complexes with sugar substrates. We find that the radius of gyration decreases by 0.95 +/- 0.24 A upon binding glucose and 1.25 +/- 0.28 A upon binding glucose 6-phosphate. This observed reduction in radius of gyration in the presence of glucose is the same as that calculated from the coordinates of the high-resolution crystal structures of native hexokinase B and a glucose complex with hexokinase A. Thus, these measurements suggest that the dramatic closing of the slit between the two lobes of hexokinase observed in the crystal structures (Bennett, W.S., & Steitz, T.A. (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 4848--4852) occurs in solution when either glucose or glucose 6-phosphate is bound.

Glucose↗
PubMed1978

Bioaccumulation and detection of trace levels of cadmium in aquatic systems by Eichhornia crassipes.

The water hyacinth (Eichhornia crassipes) may be used as a sensitive biological indicator for continuously monitoring trace quantities of toxic heavy metals in aquatic systems. A river water system polluted with cadmium was simulated while other factors of temperature, day-night cycle, water quality, and light intensity remained constant. When the water hyacinth is maintained in river water containing 0.001 mg/l. of cadmium chloride, the plant's root system will concentrate this element at an average rate of 0.9, 1.4, and 3.0 mug Cd/g root dry weight after 24, 48, and 72 hr exposure periods, respectively. At a higher cadmium concentration of 0.01 mg/l., cadmium was concentrated in the roots much faster to levels of 6.8, 13.6, and 39.1 mug/g root after 4, 8, and 24 hr exposure periods, respectively. At initial concentrations of 0.05 mg/l. cadmium, the roots contained 29.5, 48.8, and 156 mug/g root following 4, 8, and 24 hr exposure periods, respectively. During these same time intervals, the water hyacinth sorbed 56.7, 153, and 281 mug/g root when the initial cadmium concentration was increased to 0.10 mg/l. The water hyacinth tops can also assist in the monitoring process when cadmium contamination levels are 0.10 mg/l. and greater. At this initial cadmium concentration, cadmium is translocated into the tops. After 8 hr, the tops averaged 1.1 mug/g top. After 24 hr, this concentration was increased to 6.1 mug/g top.

Cadmium↗
PubMedDate not supplied

Treatment patterns among adult patients with asthma: factors associated with overuse of inhaled beta-agonists and underuse of inhaled corticosteroids.

BACKGROUND: Overuse of inhaled beta-agonists and underuse of inhaled corticosteroids by patients with asthma may have adverse consequences. This study was performed to identify factors associated with misuse of these types of asthma medication. METHODS: We examined baseline data from a longitudinal survey of adult patients with asthma. The setting was a consortium of 15 national managed care organizations serving 11 large employers. Baseline surveys were completed by 6612 health plan enrollees at least 18 years old who had had at least 2 visits with a diagnostic code for asthma in the preceding 2 years. The main outcome measures were the overuse of inhaled beta-agonists and the underuse of inhaled corticosteroids. Independent variables were patient and process of care factors. RESULTS: Among patients with moderate or severe asthma, 16% of users of inhaled beta-agonists reported overuse (>8 puffs per day on days of use), and 64% of users of inhaled corticosteroids reported underuse (use on < or =4 days/wk or < or =4 puffs per day). Overuse of inhaled beta-agonists was most strongly associated with concomitant treatment with inhaled corticosteroids or anticholinergic agents, increased asthma symptom severity, problems in obtaining asthma medication, and male sex. Underuse of inhaled corticosteroids was associated with nonwhite race, younger age (18 to 34 years), lower use of inhaled beta-agonist, lower symptom severity, and not possessing a peak flow meter. Rates of misuse of medication also varied by speciality of the patient's provider (generalist, allergist, or pulmonologist). CONCLUSIONS: Overuse of inhaled beta-agonists may be caused by symptom severity, while underusers of corticosteroids may interrupt use as symptoms abate. This study demonstrated an important opportunity to improve medication use among patients with asthma.

Administration, Inhalation↗