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Biomedical subjects

O Miettinen

Publications and source records attributed to O Miettinen.

5 recordsLinked to original sources

Preschool behavior disorders: their prevalence in relation to determinants.

The occurrence of behavior disorders was investigated in a prospectively followed 3-year-old birth cohort. Of 1116 eligible children, the parents of 918 were successfully contacted. All agreed to complete a telephone interview and were mailed a Childhood Behavior Checklist (CBCL) standardized for 2- to 3-year-old children; 756 (82%) returned the CBCL. The prevalence of one or more of the deviant behavior syndromes identified by the CBCL was 11.1%. From a number of subject characteristics recorded throughout infancy, age-specific determinants for the occurrence of these deviant behaviors were identified. Characteristics most consistently associated with preschool psychopathology included the mother's ill health and lack of social support, the presence of chronic illness in the child, and the frequent use of hospital emergency services. These and other determinant (risk) indicators were entered into logistic regression (LR) models to derived adjusted relative risk estimates for the occurrence of a behavior disorder. The derived LR equations emphasize the important role of both the mother as well and the father and the health of the child.

Affective Symptoms

Estimability and estimation in case-referent studies.

The concepts that case-referent studies provide for the estimation of "relative risk" only if the illness is "rare", and that the rates and risks themselves are inestimable, are overly superficial and restrictve. The ratio of incidence densities (forces of morbidity)-and thereby the instantaneous risk-ratio-is estimable without any rarity-assumption. Long-term risk-ratio can be computed through the coupling of case-referent data on exposure rates for various age-categories with estimates, possibly from the study itself, or the corresponding age-specific incidence-densities for the exposed and nonexposed combined-but again, no rarity-assumption is involved. Such data also provide for the assessment of exposure-specific absolute incidence-rates and risks. Point estimation of the various parameters can be based on simple relationships among them, and in interval estimation it is sufficient simply to couple the point estimate with the value of the chi square statistic used in significance testing.

Epidemiologic Methods

Comparative analysis of two rates.

In this paper, we examine comparative analysis of rates with a view to each of the usual comparative parameters-rate difference (RD), rate ratio (RR) and odds ratio (OR)-and with particular reference to first principles. For RD and RR we show the prevailing statistical practices to be rather poor. We stress the need for restricted estimation of variance in the chi-square function underlying interval estimation (and also point estimation and hypothesis testing). For RR analysis we propose a chi-square formulation analogous to that for RD and, thus, one which obviates the present practice of log transformation and its associated use of Taylor series approximation of the variance. As for OR analysis, we emphasize that the chi-square function, introduced by Cornfield for unstratified data, and extended by Gart to the case of stratified analysis, is based on the efficient score and thus embodies its optimality properties. We provide simulation results to evince the better performance of the proposed (parameter-constrained) procedures over the traditional ones.

Biometry