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Biomedical subjects

E B Larson

Publications and source records attributed to E B Larson.

At least 235 records · Page 13Linked to original sources

The cost effectiveness of therapeutic and prophylactic leukocyte transfusion.

We analyzed the cost effectiveness of leukocyte transfusion in preventing death from infection during intensive chemotherapy for acute leukemia. Effectiveness was estimated with an odds-ratio analysis based on published results of controlled studies of therapeutic and prophylactic leukocyte transfusion. Cost estimates were based on blood-bank charges throughout the country. Calculations of effectiveness suggest that leukocyte transfusion might prevent 50 to 75% of early deaths from infection. Therapeutic transfusion would add approximately 10.9% to the hospital bill of the average bill of the average leukemic patient and cost $17.7 million annually nationwide. Prophylactic transfusion would add 35.2% to the hospital bill and cost $57.8 million annually. Mean cost-effectiveness ratios were $14,982 per life-year for therapeutic transfusion and $35,020 to $50,029 per life-year for prophylactic transfusion. The cost per additional life-year achieved with prophylactic rather than therapeutic leukocyte transfusion was $85,291. These data suggest that leukocyte transfusion is an extremely expensive technologic procedure.

Acute Disease↗

Diagnostic evaluation of headache. Impact of computerized tomography and cost-effectiveness.

One hundred sixty-one highly selected patients with headache were studied to assess the impact of computerized tomography (CT) on diagnostic evaluation and to determine cost-effectiveness of neurodiagnostic evaluation of headache. Fewer nuclide brain scans were performed after availability of CT, but diagnostic charges stayed about the same. A careful history and physical and neurological examinations were adequate screens to detect intracranial mass lesions or systemic disease associated with headache. In patients with normal findings from neurological examination, no clinically important abnormalities were detected by CT, skull roentgenogram, angiography, or nuclide brain scan. The cost of finding a case of brain tumor was estimated to be at least $1,265 for patients with abnormalities on neurological examination and $11,901 for patients with normal findings on neurological examination. Neurodiagnostic evaluation of headache patients with normal findings from neurological examination is expensive and was clinically unrewarding in this series.

Brain↗

Tick-borne relapsing fever in the Pacific Northwest: an underdiagnosed illness?

Some 30 cases of tick-borne relapsing fever due to Borrelia are known to have occurred between 1965 and 1978 in the Pacific Northwest. This disease was found more frequently in young men with a history of wilderness exposure during the summer months. Recurrent fever was the most common symptom with temperatures reaching higher than 39.5 degrees C (103.1 degrees F) in all cases, and many patients had three or more febrile episodes. Splenomegaly was the second most common finding reported. Diagnosis of relapsing fever was made in 20 cases by identifying spirochetes on peripheral blood smears. In ten remaining cases the diagnosis was made on clinical and epidemiologic grounds.Information regarding therapy was available in 21 cases. Ten patients received a tetracycline drug and all had a prompt response without relapse. Two of the patients died, a 68-year-old woman with possible myocardial involvement and a newborn infant with infection acquired in utero and meningeal involvement. The diagnosis was often delayed in spite of outpatient evaluation and admittance to hospital, probably because borreliosis was not considered in the differential diagnosis. Because tick-borne relapsing fever is eventually a self-limited disease in most patients, it is probably not recognized often enough. Awareness of this disease and examination of the peripheral blood smear for spirochetes will lead to earlier diagnosis. Prompt initiation of tetracycline therapy should reduce morbidity associated with borreliosis.

Adult↗

The relationship of health beliefs and a postcard reminder to influenza vaccination.

The relationship of certain health beliefs to influenza vaccination and the effect of a postcard reminder on vaccination rates was studied among 232 high-risk patients. In agreement with the Health Belief Model tested, the patients vaccinated believed influenza to be more serious, believed they were more susceptible to influenza, and believed the vaccine to be more efficacious than did patients not vaccinated. Those not vaccinated were less satisfied with their medical care and felt the vaccine was more expensive than those vaccinated. A postcard reminding patients of influenza vaccination was an effective way to increase the vaccination rate. Patients receiving the card had a 59.7 percent vaccination rate compared to a 30.0 percent rate among those not receiving the postcard. This study suggests that a reminder postcard is an effective means to promote influenza vaccination and that these beliefs are important determinants of vaccination behavior.

Attitude to Health↗

Computed tomography in patients with cerebrovascular disease: impact of a new technology on patient care.

The medical care of 157 patients with suspected cerebrovascular disease was analyzed to assess the impact of the new technology, computed tomography (CT) of the brain, on the care of these patients. A cohort of patients admitted before installation of CT was compared to two cohorts admitted after installation of CT. Length of hospital stay, speed of diagnostic workup, treatment, and discharge plans were not significantly different. Discharge diagnoses were more specific after installation of CT. Lumbar punctures and radionuclide brain scans were used less frequently, but utilization of other diagnostic studies was unchanged. Aggregate charges for diagnostic procedures actually increased in both after-CT groups. In this study, addition of CT to the neurodiagnostic armamentarium resulted in little demonstrable improvement in the care of these patients with cerebrovascular disease but did increase the cost of evaluation. This is unlike the situation for patients with brain tumors, where CT was shown to improve care while not increasing cost. These results may help guide the use of CT by physicians caring for patients with cerebrovascular disease and suggest that health planners not use all patients with cerebrovascular disease in estimating need for CT.

Brain↗

Impact of computed tomography on the care of patients with suspected hydrocephalus.

To assess the impact of computed tomography (CT) on patient care, a cohort of patients with suspected hydrocephalus admitted before installation of CT was compared to a similar cohort admitted after installation of CT. The after CT cohort used significantly fewer pneumoencephalograms and radionuclide brain scans. The average cost of neurodiagnostic evaluation was 22% less after CT. However, speed of workup, therapy, institution of therapy, discharge plans, and discharge diagnoses were not different for the two cohorts. We conclude that CT has made the diagnostic evaluation of patients who otherwise would have required pneumoencephalography for suspected hydrocephalus less expensive and less hazardous.

Brain↗

Impact of computed tomography on utilization of cerebral angiograms.

In order to assess the effects of computed tomography (CT) of the brain on utilization of cerebral angiography, a retrospective analysis of three cohorts of patients was undertaken. Each cohort consisted of 50 consecutive patients receiving angiography either before a CT scanner was available, after installation of CT, or 1 year after CT. Since availability of CT, a progressive decrease in the proportion of angiograms that are normal has occurred (from 36% to 16%). Patients being evaluated for mass lesions account for the decrease. We conclude that CT is making neurodiagnostic evaluation more efficient and less invasive for patients with suspected mass lesions.

Adolescent↗

Funding for medical care research.

Funding for medical care research in the interrelated fields of health services research, clinical decision-making, clinical epidemiology, the medical humanities and social sciences, and medical education has been unstable, and relatively little is available in the form of investigator-initiated grants. Stable funding for these fields is important to society and critical to the healthy development of academic general internal medicine. Strategies to augment funding can include political interventions to increase support for the National Center for Health Services Research and Health Care Technology Assessment and to secure designated funds within the National Institutes of Health. Public funding is also needed for career development awards in these fields. Research support also could be enhanced by establishing a consortium of foundations interested in funding investigator-initiated grants through open competition, by developing a mechanism for reviewing proposals from small foundations, by developing consortia in the private sector to support focused research, and by developing endowments to support research.

Financing, Government↗

Transfer bias and the association of cognitive impairment with falls.

The authors hypothesized that cognitive impairment is associated with falls in older adults, but that transfer bias may obscure this association in cross-sectional community studies. The bias would arise if demented patients who fall are relatively unavailable to community surveys due to death or institutionalization. To test this hypothesis, a "dose-response" relationship between falls and cognitive impairment was tested for using data from a longitudinal cohort study of 157 patients with Alzheimer-type dementia. In a cross-sectional analysis of baseline data, when 96% of the cohort were community residents, the association between falls and cognitive impairment was insignificant (odds ratio for a 10-point change in Mini-mental State score = 1.2, 95% confidence interval 0.76-1.9). Yet cognitive impairment at baseline predicted falls during three-year follow-up (OR = 1.8, 95% CI 1.1-3.0). Both severity of dementia and falls were risk factors for death or institutionalization. Patients at highest risk for leaving the community during follow-up were those who became non-ambulatory. The authors conclude, based on longitudinal data, that there is a dose-response effect between cognitive impairment and falls. Transfer bias probably obscured the association at baseline. These data emphasize the importance of prospective studies of falls.

Accidental Falls↗

Visual impairment and cognitive dysfunction in Alzheimer's disease.

OBJECTIVE: To determine whether impaired visual acuity is associated with dementia and cognitive dysfunction in older adults. DESIGN: Paired case-control comparisons of the relative frequencies of visual impairment in demented cases and nondemented controls. Cohort analyses of correlation between visual acuity and cognitive functioning in demented cases. SETTING: Internal medicine clinics at two academically affiliated medical centers. PARTICIPANTS: Eighty-seven consecutively selected patients greater than or equal to 65 years of age with mild-to-moderate, clinically diagnosed Alzheimer's disease (cases) and 87 nondemented controls matched to the cases by age, sex, and education. MEASUREMENTS AND MAIN RESULTS: The prevalence of visual impairment was higher in cases than in controls [unadjusted odds ratio for near-vision impairment = 2.7 (95% CI = 1.4, 5.2); unadjusted odds ratio for far-vision impairment = 2.1 (95% CI = 1.02, 4.3); odds ratios adjusted for family history of dementia, depression, number of medications, and hearing loss were 2.5 (95% CI = 1.1, 10.5) for near-vision impairment and 1.9 (95% CI = 0.8, 4.6) for far-vision impairment]. When further stratified by quartiles of visual acuity, no statistically significant "dose-response" relationship between vision impairment and dementia risk was observed. Among cases, the degree of visual impairment was significantly correlated with the severity of cognitive dysfunction for both near and far vision (adjusted ps less than 0.001). CONCLUSIONS: Visual impairment is associated with both an increased risk and an increased clinical severity of Alzheimer's disease, but the increased risk may not be consistent with a progressive dose-response relationship. Further studies are needed to determine whether visual impairment unmasks and exacerbates the symptoms of dementia or is a marker of disease severity.

Aged↗

Driving and Alzheimer's disease.

OBJECTIVE: To examine the driving status of Alzheimer's disease (AD) patients presenting to a geriatric clinic, and to investigate the ability of brief cognitive assessment measures to identify those who are no longer able to continue driving safely. DESIGN: Based on caregivers' reports of driving status, AD patients were divided into three groups: those who were still driving with no difficulty, those still driving but having difficulty, and those who had stopped driving due to their cognitive problems. Scores on commonly used cognitive tests were compared across groups. Age, gender, and duration of dementia were also investigated. SETTING: The University of Washington Medical Center (UWMC) outpatient Geriatric and Family Services Clinic. PARTICIPANTS: One hundred consecutive patients who met DSM-III-R criteria for primary degenerative dementia and were either currently driving or had stopped driving due to cognitive deficits. MEASUREMENT AND MAIN RESULTS: Twenty-two subjects were reportedly still driving with no difficulty, 23 were still driving with difficulty, and 55 were no longer driving. Both mental status screening and functional assessments were significantly different between drivers and nondrivers, as were scores on a visual-spatial task. In addition, gender and age distinguished the groups: younger drivers and men drivers were less likely to stop driving despite significant cognitive impairment. CONCLUSIONS: Given the large number of AD patients who continue to drive and who experience problems with driving, this investigation highlights the need for assessment of driving safety as part of a clinical dementia evaluation. In addition, the results suggest a combination of cognitive and functional measures that may be helpful in identifying patients who are at greatest risk for unsafe driving.

Aged↗