Biomedical subjects

Thomas D Cook

Publications and source records attributed to Thomas D Cook.

5 recordsLinked to original sources

PubMed2003

Azithromycin for the secondary prevention of coronary heart disease events: the WIZARD study: a randomized controlled trial.

CONTEXT: Several lines of evidence have implied an association between Chlamydia pneumoniae infection and atherogenesis. OBJECTIVE: To determine the effect of 12 weeks of antibiotic therapy on coronary heart disease events in patients with stable coronary artery disease and known C pneumoniae exposure. DESIGN, SETTING, AND PARTICIPANTS: Randomized, placebo-controlled trial of 7747 adults with previous myocardial infarction that had occurred at least 6 weeks previously (median, 2.6 years) and a C pneumoniae IgG titer of 1:16 or more. Patients were recruited from 271 clinical practices in North America, Europe, Argentina, and India, from October 10, 1997, to July 22, 2001. INTERVENTION: The patients received either azithromycin (600 mg/d for 3 days during week 1, then 600 mg/wk during weeks 2-12; n = 3879) or placebo (n = 3868). MAIN OUTCOME MEASURES: The primary event was the first occurrence of death from any cause, nonfatal reinfarction, coronary revascularization, or hospitalization for angina. Patients were followed up until 1038 events accrued. RESULTS: After a median of 14 months of follow-up, there was no significant risk reduction in the likelihood of a primary event with azithromycin vs placebo (7% [95% confidence interval, -5% to 17%], P =.23). Analysis of hazard ratios suggested early benefits of azithromycin on the primary event and on death or reinfarction, but these decreased over time. There were no significant risk reductions for any of the components of the primary end point including death (8%), recurrent myocardial infarction (7%), revascularization procedures (5%), or hospitalizations for angina (-1%). Adverse events related to study drug were reported by 13.2% of those randomized to receive azithromycin, predominantly a result of diarrhea, compared with 4.6% randomized to receive placebo, and resulted in discontinuation of drug in 1.6% of those taking azithromycin and 0.4% taking placebo. CONCLUSION: Among stable patients with previous myocardial infarction and with evidence of C pneumoniae exposure, a 3-month course of azithromycin did not significantly reduce the clinical sequelae of coronary heart disease.

Anti-Bacterial Agents↗

PubMed2003

The case for studying multiple contexts simultaneously.

Individuals live in multiple social contexts simultaneously, whether they be family, peer, neighborhood, school or work contexts. In individual lives, it is likely that the forces within any one context that promote healthy human development are correlated with whatever causal forces operate to the same end in other contexts. This paper explores why it is important to consider social contexts, not singly as in traditional neighborhood or school or work-site research, but in combination.

Adolescent↗

PubMed2002

P-value adjustment in sequential clinical trials.

Many randomized clinical trials utilize a group sequential monitoring procedure for assessing treatment efficacy during the course of the trial. For a group sequential trial in which the null hypothesis is ultimately rejected, the nominal p-value generally overstates the statistical significance of the result and some adjustment is required. Several orderings of the sample space have been proposed for performing this adjustment, each with unique operating characteristics. In this article, we compare four proposed methods with respect to the degree to which each captures the strength of evidence against the null hypothesis implied by the data. We conclude that the ordering of the sample space induced by the observed z-score has the most desirable operating characteristics.

Data Interpretation, Statistical↗

PubMed2002

Advanced statistics: up with odds ratios! A case for odds ratios when outcomes are common.

Treatment comparisons from clinical studies involving dichotomous outcomes are often summarized using risk ratios. Risk ratios are typically used because the underlying statistical model is often consistent with the underlying biological mechanism of the treatment and they are easily interpretable. The use of odds ratios to summarize treatment effects has been discouraged, especially in studies in which outcomes are common, largely because odds ratios differ from risk ratios and are frequently interpreted incorrectly as risk ratios. In this article, the author contends that risk ratios can be easily misinterpreted and that, in many cases, odds ratios should be preferred, especially in studies in which outcomes are common.

Humans↗

PubMedDate not supplied

Some ways in which neighborhoods, nuclear families, friendship groups, and schools jointly affect changes in early adolescent development.

This study assessed some ways in which schools, neighborhoods, nuclear families, and friendship groups jointly contribute to positive change during early adolescence. For each context, existing theory was used to develop a multiattribute index that should promote successful development. Descriptive analyses showed that the four resulting context indices were only modestly intercorrelated at the individual student level (N = 12,398), but clustered more tightly at the school and neighborhood levels (N = 23 and 151 respectively). Only for aggregated units did knowing the developmental capacity of any one context strongly predict the corresponding capacity of the other contexts. Analyses also revealed that each context facilitated individual change in a success index that tapped into student academic performance, mental health, and social behavior. However, individual context effects were only modest in size over the 19 months studied and did not vary much by context. The joint influence of all four contexts was cumulatively large, however, and because it was generally additive in form, no constellation of contexts was identified whose total effect reliably surpassed the sum of its individual context main effects. These results suggest that achieving significant population changes in multidimensional student growth during early adolescence most likely requires both theory and interventions that are explicitly pan-contextual.

Adolescent↗