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Biomedical subjects

C M Bell

Publications and source records attributed to C M Bell.

44 records · Page 3Linked to original sources
PubMed1978

Problems in the interpretation of the in vivo measurement of calcium by the argon-37 method: an investigation of inert-gas elimination in humans.

An investigation has been made of some physiological problems associated with the interpretation of in-vivo measurements of calcium by the argon-37 method. Inert-gas elimination in humans over a period of several days was studied using i.v. injections of Xe-133. The results imply that the exhalation rate of A-37 formed in bone will be affected by the individual's composition, in particular body fat. Comparison of calcium measurements between individuals and between laboratories is meaningful only if corrections are made for differing individual composition.

Argon↗
PubMed1968

Effect of neostigmine on integrity of ileorectal anastomoses.

Patients undergoing total colectomy and ileorectal anastomosis for chronic ulcerative colitis were divided into two groups depending on whether neostigmine was administered during the anaesthetic to reverse the muscle relaxant. Those receiving neostigmine showed a postoperative anastomotic leakage rate of 36%. In the group not receiving neostigmine the leak rate was 4%, an apparently highly significant difference. Neostigmine may produce this effect by causing contractions of the gut musculature or by vasoconstriction of the blood vessels to the suture line, resulting in local ischaemia.

Adolescent↗
PubMedDate not supplied

Predicted mortality patterns in cohort study populations exposed to different types of hazard: can SMRs show a dose-response?

The analysis of data from cohort studies by duration of exposure and time since first exposure (latent interval) has been investigated using a simulation approach. These two analyses are often performed when the estimator of risk, commonly the O/E ratio or SMR, shows evidence of a raised risk. Two measures of risk were tested in the detailed analyses: the O/E ratio and the excess death rate. The latter was found to reflect the 'dose-response' relationship more accurately for a variety of hazard types. Attention is drawn to possible biases and to the importance of adjustment for age in these analyses.

Adolescent↗
PubMedDate not supplied

Diethyl ether interference with infrared breath analysis.

Diethyl ether vapor may substantially interfere with breath alcohol analysis by instruments based on infrared absorption at 9.5 microns. Exposure of two volunteers simultaneously to diethyl ether vapor for one hour followed immediately by breath tests on the Draeger Alcotest 7110, Siemens Alcomat V5.2F, and Seres Ethylometre 679T produced apparent alcohol readings in one subject of 0.4, 0.1, and 0.1 g/100 mL of blood respectively. Positive readings persisted in this subject for more than 3 hours. The second subject produced much lower readings of 0.03, 0.01, and 0.00, respectively. Readings persisted with the Alcotest 7110 for one hour. Gas chromatographic analyses of blood and breath samples confirmed that these readings were caused by diethyl ether and not ethanol. The blood concentration of diethyl ether in Subject A immediately after exposure was 25 mg/L. This level produced no clinically detectable neurological changes in the subject.

Adult↗
PubMedDate not supplied

The association between caregiver burden and caregiver health-related quality of life in Alzheimer disease.

The burden experienced by family caregivers of individuals with Alzheimer disease (AD) affects the caregivers' overall health-related quality of life (HRQOL). Assessing the influence on HRQOL is an integral part of determining the efficacy and economic attractiveness of interventions for AD. Generic preference-weighted instruments such as the Health Utilities Index Mark 2 (HUI2) are recommended for measuring HRQOL for cost-effectiveness studies. However, these instruments focus on physical attributes and have not been tested in an AD caregiver population. We administered the HUI2 to a population of 679 caregivers to people with AD at 13 community and institutional sites in the United States. We also administered the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), a caregiver time questionnaire, and a caregiver burden instrument. The mean global HUI2 utility score for caregivers was 0.87 and varied little by the affected person's setting of care and AD stage (range, 0.86-0.89; p > 0.2). The caregiver burden scales all varied by the affected person's setting of care, and some also varied by disease severity. The mental health component summary score of the SF-36 for caregivers varied across both disease stage and setting. Caregiver time increased for caregivers of AD-affected persons with more severe cognitive impairment. Generic preference-weighted instruments may not adequately capture differences in the burden of caregivers of those with AD. The development of condition-specific preference-weighted instruments may provide the means to better estimate HRQOL in AD caregivers.

Aged↗
PubMedDate not supplied

An off-the-shelf help list: a comprehensive catalog of preference scores from published cost-utility analyses.

PURPOSE: The Panel on Cost-Effectiveness in Health and Medicine recommends an organized collection of preference measure values for health states that can be used in costutility analyses (CUAs). The authors sought to construct a catalog of preference scores from published CUAs, organize the catalog by clinical categories, and identify methods of preference score assessment. METHOD: The authors systematically searched Medline and other databases to identify original CUAs published through 1997. Information was abstracted on the health state descriptions, corresponding preference scores, method of preference score elicitation, and the source of the estimate. RESULTS: Two hundred twenty-eight CUAs were appraised. The authors found 949 health states and corresponding preference scores. Most frequently, health states pertained to the circulatory system (21.7%), health states were valued by experts (35.8%), and values were derived through community-based preference scores (23.5%). CONCLUSION: A catalog of preference scores for health states can be constructed. The catalog (http://www.hsph.harvard.edu/organizations/hcra/cuadatabase/ intro.html) may provide a useful reference tool for producers and consumers of CUAs but also underscores the methodologic variation and inconsistencies present in the field.

Consumer Behavior↗
PubMedDate not supplied

Are pharmaceuticals cost-effective? A review of the evidence.

The argument that prescription drugs are cost-effective has been made both by the pharmaceutical industry to support rising drug prices and expenditures, and by advocates of expanded drug coverage for elderly and low-income persons. A new database of 228 published cost-utility analyses sheds light on the issue. According to published data, some drugs do save money or are cost-effective, but the issue depends critically on the context in which the drug is used and the intervention with which it is compared. Cost-utility analyses funded by the drug industry tend to report more favorable results than do those funded by nonindustry sources. Cost-effectiveness analysis can help policymakers to determine whether drugs and other interventions offer value for money.

Bias↗