Biomedical subjects

S F Assmann

Publications and source records attributed to S F Assmann.

21 records · Page 2Linked to original sources

PubMed1997

Do proxy evaluations of health status predict mortality?

The ability of self-evaluations of health to predict mortality remains despite efforts to explain their contribution. To further the understanding of global evaluations, this study investigated whether proxy evaluations of health status also predict mortality. Data from the Longitudinal Study of Aging were used. For men and women, the unadjusted odds ratios for proxy evaluations exhibited a monotone relationship to 3-year and 7-year mortality rates and were predictive of 7-year mortality. This monotone relationship remained even after controlling for other factors when predicting 7-year mortality rates. However, only the fair and poor evaluations were significant, and only for men. The adjusted relationship when predicting 3-year mortality was not completely monotone, although good and poor proxy evaluations were significant. This suggests that proxy evaluations are useful, and that there are aspects of health status that are currently unmeasured but that should lend themselves to being quantified.

Activities of Daily Living↗

PubMed1996

Confidence intervals for measures of interaction.

Interaction, defined as departure of disease rates from an additive model, can be measured by the relative excess risk due to interaction, or the attributable proportion due to interaction. Point estimates can be obtained using multiple logistic regression. Using simulated case-control data, we compare several confidence interval estimation techniques for these measures. These include a symmetrical interval based on the delta method estimate of the variance, and three types of bootstrap confidence intervals. One such bootstrap method has coverage closest to the nominal level and is the most evenly balanced with respect to the direction in which intervals miss the true value. The estimation methods are applied to data from an actual case-control study, and the results are interpreted in light of the simulation study.

Case-Control Studies↗

PubMedDate not supplied

Distribution of alpha 2-adrenergic receptor binding in the developing human brain stem.

Rapid and dramatic changes occur in cardiorespiratory function during early human life. Catecholamines within select brain stem nuclei are implicated in the control of autonomic and respiratory function, including in the nucleus of the solitary tract and the dorsal motor nucleus of X. Animal and adult human studies have shown high binding to alpha 2-adrenergic receptors in these regions. To determine the developmental profile of brainstem alpha 2-adrenergic binding across early human life, we studied brain stems from five fetuses at midgestation, three newborns (37-38 postconceptional weeks), and six infants (44-61 postconceptional weeks). We used quantitative tissue receptor autoradiography with [3H]para-aminoclonidine as the radioligand and phentolamine as the displacer. In the fetal group, binding was high (63-93 fmol/mg tissue) in the nucleus of the solitary tract, dorsal motor nucleus of X, locus coeruleus, and reticular formation; it was low (< 32 fmol/mg tissue) in the principal inferior olive and basis pontis. Binding decreased in all regions with age: in infancy, the highest binding was in the intermediate range (32-62 fmol/mg tissue) and was localized to the nucleus of the solitary tract and dorsal motor nucleus of X. The most substantial decrease in binding (75%-85%) between the fetal and infant periods occurred in the pontine and medullary reticular formation and hypoglossal nucleus. Binding remained low in the principal inferior olive and basis pontis. The decreases in binding with age remained significant after quench correction. These data suggest that rapid and dramatic changes occur in early human life in the brain stem catecholaminergic system in regions related to cardiorespiratory control.

Adrenergic alpha-Agonists↗