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Biomedical subjects

A Donald

Publications and source records attributed to A Donald.

60 records · Page 4Linked to original sources

Analysis of data arising from a stratified design with the cluster as unit of randomization.

This paper discusses statistical techniques for the analysis of dichotomous data arising from a design in which the investigator randomly assigns each of two clusters of possibly varying size to interventions within strata. The problem addressed is that of assessing the statistical significance of the intervention effect over all strata. We propose a weighted paired t-test based on the empirical logistic transform for designs that randomize large aggregate clusters in each of several strata.

Biometry↗

The disability assessment for dementia scale: a 12-month study of functional ability in mild to moderate severity Alzheimer disease.

The Disability Assessment for Dementia (DAD) scale was developed and validated as a measure of functional ability in dementia. DAD results have been reported in Alzheimer disease (AD) randomized, controlled treatment trials of up to 6 months, but results beyond 6 months have yet to be described. SAB INT 12 was a randomized, double-blind, placebo-controlled, parallel-group study in mild to moderate AD that included DAD assessments at baseline, month 6, and month 12. One hundred forty-four patients with AD in the placebo arm of SAB INT 12 were followed up for 12 months. DAD scores were obtained at baseline (mean DAD = 70.1, SD = 22.2), 6 months (mean DAD = 63.7, SD = 25.2), and 12 months (mean DAD = 59.3, SD = 28.9). The rate of decline was consistent across the domains of basic activities of daily living (ADLs) and instrumental ADLs, as well as the scoring of initiation, planning, and organization. The decline in DAD total scores in mild to moderate AD averages about one point per month, which equates to the loss of one item on the DAD scale every 2 months.

Activities of Daily Living↗

A Canadian cohort study of cognitive impairment and related dementias (ACCORD): study methods and baseline results.

The overall objective of the Canadian Collaborative Cohort of Related Dementias (ACCORD) study is to describe the diagnostic distribution, natural history and treatment outcomes of individuals referred from the community to dementia clinics in Canada. Between 1997 and 1999, an inception cohort of 1,136 subjects entered into this longitudinal study. At the baseline assessment, 10.9% of the subjects were classified as "not cognitively impaired" (NCI), 30.1% as "cognitively impaired not demented" (CIND), and 59% as demented. A subclassification of CIND included amnestic 25.1%, vascular cognitive impairment 18.1%, psychiatric 17.2%, neurologic 7.3%, medical/toxic metabolic 3.5%, mixed 7.6% and not specified 19.0%. The percentage of the cohort referred with dementia increased progressively each decade, while the proportions of CIND and NCI decreased. Within the dementia group, Alzheimer's disease accounted for 47.2% of the subjects, mixed dementias 33.7%, vascular dementia 8.7%, frontotemporal degenerations 5.4%, dementia with Lewy bodies 2.5%, and unclassifiable 1.8%. The ACCORD cohort will allow a detailed study of the longitudinal course of CIND, and the longer-term outcomes of both treated and untreated dementia subjects.

Adult↗

Aggregation of multiple risk factors for stroke in siblings of patients with brain infarction and transient ischemic attacks.

Hypertension, heart disease, and diabetes are not only the major risk factors for stroke, but they tend to cluster in families. It is unknown, however, whether these conditions occur more frequently among relatives of patients with specific types of stroke as compared to non-relatives. The frequencies of stroke and its major risk factors in two groups of subjects were compared. One group consisted of 76 siblings of 41 patients hospitalized with cerebral infarction and transient ischemic attacks in an investigative stroke unit; the other consisted of 55 siblings of the patients' spouses. The occurrence of these conditions in the relatives was determined from a questionnaire completed by the relatives and supported by information from the relatives' family physicians. When considered separately, hypertension, heart disease, and stroke occurred in a small but not statistically significant excess among the relatives in-law. However, various combinations of two or three diseases, (including diabetes), occurred in 20.9% of the patients' siblings as compared to only 3.6% of the relatives in-law (p less than 0.001). These results suggest that living siblings of patients with cerebral infarction and transient ischemic attacks may have an increased risk of stroke and cardiovascular disease as a result of multiple risk factors operating simultaneously. Prevention programs among this high risk population may be particularly worthwhile.

Aged↗

Piloting short workshops on the critical appraisal of reviews.

This paper describes a pilot programme of short workshops on the critical appraisal of review articles. The twelve workshops, which ran in various parts of the United Kingdom during 1992 and 1993, lasted either one or two half-days, and consisted of a mixture of large-group sessions and critical appraisal in small groups of a systematic review. The 274 participants came from varied backgrounds, though chiefly in public health and purchasing. The workshops were well received and were oversubscribed. Participants reported that they found them useful and that they raised their awareness of the place of evidence about effectiveness in decision-making. The challenge now is to evaluate the impact of such workshops more rigorously.

Health Personnel↗