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Biomedical subjects

M Susser

Publications and source records attributed to M Susser.

At least 127 records · Page 7Linked to original sources
PubMed1984

Causal thinking in practice: strengths and weaknesses of the clinical vantage point.

The place of causal inference in clinical practice is considered. One function relates to the validation of existing knowledge, as in the evaluation of the medical literature, and is exemplified by the process of editorial selection. A second function relates to the validation of potential knowledge, as in the testing of hypotheses, and is exemplified by the pursuit of a nutritional cause of retarded mental development. Features of clinical practice that contribute strengths or weaknesses to causal inference are then examined. These include the diagnostic process, the effect of cumulative clinical experience, continuity of observation and follow-up, and the focus on disease.

Child↗
PubMed1984

Age at death used to assess the effect of interhospital transfer of newborns.

In New York City, newborn units classified as level 1 (no intensive care) frequently transfer low-birth-weight infants to units classified as level 3 (complete intensive care), but level 2 units (those with intermediate levels of care) transfer rarely. As deaths occurring in the first hours of life are unlikely to be affected by infant transport services, early (first four hours), late (four hours to 28 days), and overall neonatal death rates were separately examined at each of the three levels of care for singleton live-births weighing 501 to 2,250 g. As previously reported, overall neonatal mortality (adjusted for birth weight, gestational age, sex, and race) for births at level 1 units (163.0/1,000) and level 2 units (168.1/1,000) was similar, and rates for births at level 3 (128.0/1,000) were significantly lower. Mortality up to four hours, and from four hours to 28 days, however, differed between level 1 and level 2 units. Among early deaths, the mortality for level 1 births was 68.0/1,000, significantly higher than both the rate for level 2 births (46.0/1,000) and for level 3 births (40.6/1,000). Between four hours and 28 days, mortality relative to level 3 improved for level 1 births, but worsened for level 2 births. For infants with birth weight less than 1,251 g, for whom transport rates from level 1 units are highest, mortality in level 1 births was higher than in level 2 births only until 18 hours of life; thereafter, level 2 mortality was higher.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1983

Maternal smoking and trisomy among spontaneously aborted conceptions.

In a study of spontaneous abortions, we found an apparently robust association of trisomy with smoking that varies with maternal age. Among women under age 30, smoking either before or at the time of conception is less common in women aborting trisomic conceptions than in controls delivering at 28 weeks or later. Among older women, smoking is more common in women aborting trisomic conceptions than in controls. Our results point to an effect of smoking on the frequency of trisomic abortions that varies with age, and they suggest that the causes of recognized trisomic abortions differ in younger and older women.

Abortion, Spontaneous↗
PubMed1982

Newborn intensive care and neonatal mortality in low-birth-weight infants: a population study.

We examined the neonatal mortality rates of low-birth-weight infants (501 to 2250 g) born between 1976 and 1978 in three kinds of hospitals in New York City: those with newborn-intensive-care units (Level 3), those with capabilities for the care of most premature infants (Level 2), and those without any special facilities for premature newborns (Level 1). Among 13,560 singleton low-birth-weight infants, the adjusted neonatal mortality rate for Level 3 hospitals was 128.5 per thousand live births - significantly lower (P less than 0.001) than the rates for both level 2 (168.1) and Level 1 units (163.0). The association of level of care with mortality could not be accounted for by differences between groups in social or demographic status, in prenatal care, or in medical complication of pregnancy. We infer that birth at a Level 3 center lowers neonatal mortality in low-birth-weight infants. However, only 34 per cent of the patients in this study were born in such units.

Critical Care↗
PubMed1982

Period effects, generation effects and age effects in peptic ulcer mortality.

The interpretation of secular trends in terms of period, age and cohorts is illustrated by data on peptic ulcer mortality for England and Wales from 1900 to 1977. Approaches to the external validation of the inferences made from such analyses are also illustrated. These data conform with predictions from a cohort analysis of some 20 years ago that peptic ulcer mortality and morbidity would decline.

Age Factors↗
PubMed1982

Prenatal starvation and maternal blood pressure near delivery.

Maternities in cities exposed to the Dutch famine of 1944 to 1945 and in control cities were compared. Systolic blood pressure near the time of delivery was significantly reduced by exposure to famine late in the 2nd trimester and early in the 3rd trimester. Blood pressure correlated best with caloric rations in the 3rd month before delivery, and this relationship holds consistently below a ration level of 1900 cal. Above 1900 cal and up to 2200 cal (the upper limit of rations for the data analyzed) the relationship is inconsistent across cities. Edema, analyzed in one city, varied in a manner similar to blood pressure.

Blood Pressure↗
PubMed1982

Effects of prenatal nutritional supplementation on the placenta: report of a randomized controlled trial.

Protein and nucleic acid content, and RNase levels were measured in placentas collected at birth in a randomized controlled trial of prenatal nutritional supplementation in New York City. These biochemical indices were explored to understand better the effects of nutritional supplementation. (With high-protein supplements, gross measures had shown no improvement in outcome at birth and adverse effects on fetal growth, prematurity, and newborn survival; with balanced protein-calorie supplements, there was a nonsignificant rise in birth weight and longer gestation.) The biochemical indices were in general somewhat weakly related to fetal growth measures. Significant effects of nutritional treatment on the indices were minimal, and added no information that could account for gross effects observed in the fetus.

Birth Weight↗
PubMed1982

Social class indicators and mortality in low birth weight infants.

This study examines the utility of birth weight-specific neonatal mortality rates in removing the confounding effects, in comparisons of mortality in low birth weight infants, of several factors that influence crude neonatal mortality. For this purpose, the effects of social, demographic, and biological attributes of mothers on the mortality of their low birth weight babies were examined in the total population of infants weighing 501-2000 gm born in New York City in 1976, 1977, and the first 11 months of 1978 (N = 10,187). The results confirm previous observations that race, sex, and gestational age-for-weight all exert significant influences on mortality even within narrow (250 gm) birth weight bands. However, mothers' education, number of prenatal visits and whether delivery was on private or ward service, all variables which substantially affect crude neonatal mortality, had no overall effect on weight-specific mortality in the weight range under consideration. Two other socioeconomic indicators, whether delivery was financed by Medicaid, and the marital status of the mother, did significantly affect weight-specific mortality, but their effects were abolished when gestation, race, and sex were entered into the analysis. Although neither maternal age nor parity had any significant individual effects on low birth weight mortality, a linear trend towards lower mortality in older mothers was discovered, and certain age-parity combinations experienced significantly elevated or reduced mortality. In general, weight-specific mortality in low birth weight infants is little influenced by the socioeconomic circumstances of their mothers, particularly when race, sex, and gestation are taken into account. Weight-specific neonatal mortality can therefore be a useful tool in the analysis of the effectiveness of perinatal medical care given to low birth weight infants.

Adolescent↗