Biomedical subjects

A S Bates

Publications and source records attributed to A S Bates.

24 records · Page 2Linked to original sources

PubMed1994

Risk factors for underimmunization in poor urban infants.

OBJECTIVE: To assess risk factors for underimmunization in poor urban infants. DESIGN: Prospective cohort study. SETTING: A large municipal teaching hospital in the Midwest. PARTICIPANTS: A total of 464 healthy, full-term newborn infants delivered at a large municipal teaching hospital who were to be discharged to the care of their mothers. Mothers were interviewed 24 to 72 hours post partum regarding personal and financial characteristics and 9 to 12 months later to determine where immunizations had been received. MAIN OUTCOME MEASURES: Immunization status at 3 and 7 months of age. RESULTS: Despite availability of free vaccine to most patients, only 67% had received their first set of immunizations by 3 months of age, and only 29% were up-to-date by 7 months of age. Marital status, coresidence with the infant's grandmother, adequacy of prenatal care, and perceived barriers to care were significant independent predictors of initiation of immunizations by 3 months and completion of immunization by 7 months. Poverty was also an independent predictor of immunization status at 7 months. Perceived susceptibility to common symptoms and perceived benefit of medical care to prevent disease were inversely related to immunization status at 7 months. CONCLUSIONS: These data suggest that poor urban infants of single mothers and of mothers who received inadequate prenatal care, and those not living with their grandmother should be targeted for tracking and follow-up to ensure adequate immunization. The provision of free vaccine alone will not guarantee adequate immunization coverage of poor urban children.

Adult↗

PubMed1994

Reliability and validity of an instrument to measure maternal health beliefs.

Noncompliance with recommended preventive pediatric care continues to be a major problem, especially in inner-city pediatric clinics. There has been little evaluation of the maternal beliefs that are associated with such noncompliance, perhaps because there are no instruments which have been assessed for reliability and validity. To evaluate the internal consistency and construct validity of a maternal health belief instrument, we interviewed 500 mothers of healthy full-term newborns postpartum. Forty-eight items measured the maternal health beliefs, according to Health Belief Model constructs (perceived susceptibility, perceived severity, perceived benefits of medical care, perceived barriers, and health motivation). Construct validity was assessed by principal components factor analysis. Eight internally consistent indices emerged, including illnesses having high and low perceived susceptibility, and low and moderate perceived benefit. Logistical access barriers and economic access barriers were also distinct. Perceived severity and health motivation formed single indices. This maternal health belief instrument was internally consistent in the study sample and showed evidence of construct validity. These indices may make important independent contributions to understanding variation in preventive well-child care utilization.

Adult↗

PubMed1994

The Parent Health Belief Scales: replication in an urban clinic population.

Health locus of control (HLC) has been used to operationalize general health motivation. This study was undertaken to evaluate the internal consistency and construct validity of Tinsley and Holtgrave's Parent Health Belief Scales (PHBS) as a measure of maternal HLC toward their children's health. Five hundred mothers (71% of eligible consecutive admissions) of newborns admitted to the normal newborn nursery of a large municipal teaching hospital were interviewed 24 to 72 hours after delivery. Principal components factor analysis of the PHBS did not support the originally hypothesized three-dimensional factor structure of the PHBS. In addition, the original subscales did not have adequate internal consistency reliability. Further assessment of construct validity by comparison with maternal preventive health behaviors showed some evidence of construct validity for the scales when compared with breastfeeding behavior. When the three items written as reverse-coded Internality items are not reversed, a reliable seven-item Externality scale emerges which contains items originally thought to represent all three dimensions of HLC.

Adult↗

PubMed1994

p53 Protein accumulates in Cushings adenomas and invasive non-functional adenomas.

The p53 protein, a negative regulator of cell growth, plays an important role in the pathogenesis of many human tumours following gene mutation and/or deletion. We screened a large number of sporadic pituitary tumours for p53 protein accumulation suggestive of gene mutation. Samples were divided into benign adenomas (n = 95) and invasive tumours with local or distant invasion (n = 26). All main tumour classes were represented. Putative p53 mutations were detected by immunohistochemistry on paraffin-embedded sections using polyclonal CM-1 and monoclonal DO-7 and PAb1801 antibodies. Results were compared to normal post-mortem pituitary tissue controls (n = 17). p53 protein accumulation was detected in invasive tumours (16%), but only in corticotrophinomas (2/4) and non-functional tumours (4/15). In non-invasive adenomas, protein accumulation was observed only in ACTH-secreting tumours where 50% were positive (16/32). No protein accumulation was identified in any control tissue. These results indicate that p53 protein accumulation may play a role in the development of Cushings adenomas and in the progression of non-functional tumours to the invasive state.

Adenoma↗

PubMed1993

Verification bias in pediatric studies evaluating diagnostic tests.

Improperly designed evaluations of diagnostic tests may lead to inaccurate conclusions about a test's accuracy. One problem, verification bias, occurs if subjects are not equally likely to have the diagnosis verified by a gold-standard evaluation and if selection for further evaluation is dependent on the diagnostic test result. To determine whether verification bias is a problem in pediatric studies of diagnostic tests, we conducted a critical appraisal of all studies evaluating diagnostic tests published in three pediatric journals during a 3-year period. Thirty-six percent were subject to verification bias. The most prevalent cause was restriction of the patient sample to those whose diagnosis had been verified by a gold standard evaluation, when the decision to obtain the gold standard was influenced by the diagnostic test result. Verification bias may have serious effects on the estimated sensitivity and specificity of a test. Improved awareness of the potential for verification bias may help physicians improve their selection and interpretation of diagnostic tests and thereby improve the quality and efficiency of patient care.

Bias↗

PubMed1993

An audit of outcome of treatment in acromegaly.

In order to determine whether acromegaly is still associated with increased mortality, a hospital case note review of all patients with acromegaly followed up in Stoke-on-Trent since 1967 was carried out. Of 79 subjects identified, 51 are alive and being monitored and 28 have died. Mortality was compared to the general population by life table analysis. Secretion of growth hormone was assessed and compared in dead and alive patients. The effect of diabetes, hypertension, and growth hormone secretion on long-term outcome was assessed. Acromegaly is still associated with increased mortality, with an overall ratio of observed to expected deaths equal to 2.68 (95% C.I. 1.8-3.9; p < 0.001), but the survival of 31 (39%) patients whose growth hormone level had been reduced to below 5 mU/l was equal to that of the general population (O/E = 1.42; 95% C.I. 0.46-3.31: p > 0.05). The dead patients had had significantly higher growth hormone levels than those still alive, but mortality did not appear to be influenced by diabetes or hypertension. The cause of death was vascular in 57% of cases. Growth hormone hypersecretion is still associated with excess mortality in acromegaly. The present study suggests that the therapeutic objective should be to lower average daytime growth hormone levels to less than 5 mU/l. There is need for a large study to compare different modes of treatment in terms of their effect on growth hormone secretion and on long-term outcome.

Acromegaly↗