Biomedical subjects

T Capizzi

Publications and source records attributed to T Capizzi.

4 recordsLinked to original sources

PubMed1999

Randomised, placebo controlled trial of effect of a leukotriene receptor antagonist, montelukast, on tapering inhaled corticosteroids in asthmatic patients.

OBJECTIVE: To determine the ability of montelukast, a leukotriene receptor antagonist, to allow tapering of inhaled corticosteroids in clinically stable asthmatic patients. DESIGN: Double blind, randomised, placebo controlled, parallel group study. After a single blind placebo run in period, during which (at most) two inhaled corticosteroids dose decreases occurred, qualifying, clinically stable patients were allocated randomly to receive montelukast (10 mg tablet) or matching placebo once daily at bedtime for up to 12 weeks. SETTING: 23 academic asthma centres in United States, Canada, and Europe. PARTICIPANTS: 226 clinically stable patients with chronic asthma receiving high doses of inhaled corticosteroids (113 randomised to montelukast and 113 to placebo). INTERVENTIONS: Every 2 weeks, the inhaled corticosteroids dose was tapered, maintained, or increased (rescue) based on a standardised clinical score. MAIN OUTCOME MEASURES: Last tolerated dose of inhaled corticosteroids. RESULTS: Compared with placebo, montelukast allowed significant (P=0. 046) reduction in the inhaled corticosteroid dose (montelukast 47% v placebo 30%; least square mean difference 17.6%, 95% confidence interval 0.3 to 34.8). Fewer patients on montelukast (18 (16%) v 34 (30%) placebo, P=0.01) required discontinuation because of failed rescue. CONCLUSIONS: Montelukast reduces the need for inhaled corticosteroids among patients requiring moderate to high doses of corticosteroid to maintain asthma control.

Acetates↗

PubMed1999

Adjusted regression trend test for a multicenter clinical trial.

Studies using a series of increasing doses of a compound, including a zero dose control, are often conducted to study the effect of the compound on the response of interest. For a one-way design, Tukey et al. (1985, Biometrics 41, 295-301) suggested assessing trend by examining the slopes of regression lines under arithmetic, ordinal, and arithmetic-logarithmic dose scalings. They reported the smallest p-value for the three significance tests on the three slopes for safety assessments. Capizzi et al. (1992, Biometrical Journal 34, 275-289) suggested an adjusted trend test, which adjusts the p-value using a trivariate t-distribution, the joint distribution of the three slope estimators. In this paper, we propose an adjusted regression trend test suitable for two-way designs, particularly for multicenter clinical trials. In a step-down fashion, the proposed trend test can be applied to a multicenter clinical trial to compare each dose with the control. This sequential procedure is a closed testing procedure for a trend alternative. Therefore, it adjusts p-values and maintains experimentwise error rate. Simulation results show that the step-down trend test is overall more powerful than a step-down least significant difference test.

Aged↗

PubMed1986

Tentative interpretive criteria for in vitro antibacterial susceptibility testing with imipenem.

Imipenem is a member of a new class of highly potent beta-lactam antibiotics, carbapenems, with a very broad antibacterial spectrum. This study was undertaken to determine tentative interpretive criteria for in vitro susceptibility testing with 10-micrograms imipenem disks. A careful examination of the zone diameters and the corresponding MICs for 489 clinical isolates by regression-line analysis and the error rate-bounded classification scheme suggested the following guidelines: greater than or equal to 16 mm with an MIC correlate of less than or equal to 4 micrograms/ml for susceptible, 14 to 15 mm (8 micrograms/ml) for moderately susceptible, and less than or equal to 13 mm (greater than or equal to 16 micrograms/ml) for resistant. Lack of cross-resistance between imipenem and broad-spectrum cephalosporins such as cefotaxime and ceftazidime argues against their use as class disks to predict in vitro susceptibility of bacterial species to carbapenems.

Bacteria↗

PubMed1983

Model-independent procedure for area estimation and intergroup comparisons.

A method is provided for estimating the area under a response-time curve for an experimental situation where independent observations are made at each time point. The procedure utilizes least-squares spline functions and the jackknife technique to provide area estimates, standard errors, and a statistical test for intergroup comparisons. The method is based on an empirical model and provides a means of analysis when no prior model can be specified or if the incorrect specification of a model will produce invalid results. The method is illustrated using data from a study comparing the pharmacokinetic behavior of a fasciolicide in rats having either a young or old parasitic infestation. The results obtained are comparable with those generated by a model-dependent approach.

Animals↗