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At least 559 records · Page 31Linked to original sources
PubMed2001

Sample size calculations for the two-sample problem using the multiplicative intensity model.

In this paper we propose formulae for calculating the expected number of events or, alternatively, the required trial duration, for clinical trials involving two treatment groups in which patients may potentially experience multiple events and the data will be analysed using a multiplicative intensity (MI) model. We use a partial likelihood-based approach and examine in detail two MI models: one that includes a binary treatment variable as the only covariate and a three-state Markov process model in which a binary time-varying covariate is added to the previous model. For the simpler model, our formula coincides with those derived by Cook using full likelihood methods. We present applications of the derived formulae to chronic granulomatous disease and breast cancer data sets.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Routinization and emotional well-being: an experience sampling investigation in an elderly French sample.

This investigation examined the predictive validity of routinization preference measures, as well as the association of routinization to state affect in daily life. The authors collected naturalistic repeated observations from elderly participants living in private residences or retirement homes. Preferences for routinization were significantly associated with the repetition of both behaviors and environmental contexts. Routines were associated with decreases in positive affect in within-person analyses but had no association to anxious or depressed mood states. The findings are discussed in terms of the complexity of the routinization concept and its relevance for understanding emotional well-being in elderly people.

Activities of Daily Living↗
PubMed1990

[Amniocentesis versus choriocentesis (chorionic villi sampling) and cordocentesis (fetal blood sampling)].

Opinions are still divergent regarding the respective place of amniocentesis and choriocentesis in the scheduled prenatal diagnosis. Amniocentesis (PLA) is the oldest method. This technique is perfectly mastered as well as its results, complications; its follow-up is 17-18 years in the world and over 16 years in Lyon. The rate of technical failures is inferior to 0.5 p. cent under ultrasonographic control. Its results are quite reliable (one error in 4 to 5,000 amniocentesis for the karyotype). The culture failures are under 1 p. cent. The titration of tracers, such as alpha-feto-protein or acetyl-cholinesterase is possible, favoring PLA over choriocentesis when there is a risk of neural dysraphias. PLA may be performed at any time during the pregnancy. Its main drawback seems to be its lateness: currently, the ideal time is 15-16 weeks. PLA performed earlier may result in more technical and culture failures. When performed at 12-13 weeks, it enters in competition with the choriocentesis although its theoretical risk of abortion is lower. Therefore, PLA and choriocentesis may be competitors, according to the risk factors and the indications, especially regarding cytogenetics.

Amniocentesis↗