Biomedical subjects

S L Hui

Publications and source records attributed to S L Hui.

94 records · Page 6Linked to original sources

PubMedDate not supplied

Validation of probabilistic predictions.

Current advances in high-speed computing and increased availability of statistical software have led to widespread use of statistical methods for the development of computerized protocols predictive of binary health outcomes. If these predictive algorithms are to be used in settings other than those for which they were developed, e.g., applied in a different geographic setting or extrapolated for use in a slightly different population, then they should be carefully validated to ensure appropriate application. Miller et al. (Stat Med. 1991) provided a comprehensive methodology for external validation of logistic prediction models, and applied these methods in a temporal validation setting. In this article, the authors emphasize how these methods can be applied to general forms of probabilistic predictions and provide several SAS macros for computation of the desired statistics.

Adolescent↗

PubMedDate not supplied

Effects of computer reminders for influenza vaccination on morbidity during influenza epidemics.

To study the effects of computer-generated reminders for influenza vaccination of patients at high risk of pulmonary disease during the winter, we selected 4555 such patients from a population of 15,000 adults who participated in a three-year randomized trial of preventive-care reminders. The physicians who received the reminders vaccinated eligible patients twice as often as did the control physicians (P = 0.0001). There was a linear increase in the incidence of influenza in our area during the three winters under study (from 1000 to 33,451 to 71,075 cases per year), and we modeled the percentage of patients with hospitalizations, emergency room visits with chest radiography, and blood gas determinations as a logistic function of this increase. The difference in linear trends between the patients in the intervention group (whose physicians received reminders) and those in the control group was significant for emergency room visits (P less than 0.05), hospitalizations (P less than 0.01), and blood gas determinations (P less than 0.001). The most likely explanation for the difference is the greater use of influenza vaccine in the intervention group.

Aged↗

PubMedDate not supplied

Mortality prediction and interval until death in near-term and term neonates with respiratory failure.

Mortality risk indicators may be useful adjuncts to clinical judgment in considering the use of extraordinary and relatively high-risk treatments such as high-frequency ventilation, extracorporeal membrane oxygenation, and nitric oxide therapy. We retrospectively evaluated the reliability of published indications of high mortality, developed additional high-risk indicators, and determined the interval between the time when high-risk indicators were met and when death occurred in near-term and term neonates with respiratory failure. Patients were included in the analysis if they met the following criteria: > or = 35 weeks gestation, > or = 2 kg birth weight, < or = 7 days of age, and receiving a fraction of inspired oxygen of > or = 0.8 and mechanical ventilation. Patients were excluded if they had congenital heart disease, intracranial hemorrhage, untreatable bleeding diathesis, or lethal congenital anomaly. Fifteen patients in the 1980 to 1981 group and 41 patients in the 1985 to 1987 group met these criteria. We observed 100% mortality in our 1980 to 1981 patients who met previously published criteria predictive for > or = 80% mortality in near-term and term neonates with respiratory failure; however, mortality risk was 60% to 80% in the 1985 to 1987 group.(ABSTRACT TRUNCATED AT 250 WORDS)

Gestational Age↗

PubMedDate not supplied

Controlled prospective randomized comparison of high-frequency jet ventilation and conventional ventilation in neonates with respiratory failure and persistent pulmonary hypertension.

OBJECTIVE: The objective of this study was to evaluate the efficacy and safety of high-frequency jet ventilation in near-term and term neonates with persistent pulmonary hypertension. STUDY DESIGN: Subjects for this prospective, randomized, controlled comparison study were recruited from neonates treated in a level-three neonatal intensive care unit that accepts referrals for extracorporeal membrane oxygenation. RESULTS: In patients treated with high-frequency jet ventilation (n = 11) acute improvement in oxygenation (p = 0.008), ventilation (p < 0.001), and oxygen indices (p < or = 0.01) was demonstrated while stable peak and mean airway pressures were maintained. Control group patients receiving high-frequency positive pressure ventilation with a conventional ventilator required increasingly higher peak inspiratory pressures (p = 0.005) to maintain oxygenation, ventilation, and oxygen indices. There were no significant differences in survival without use of extracorporeal membrane oxygenation, nor were there differences in duration of oxygen therapy, ventilation, and hospitalization; need for extracorporeal membrane oxygenation; or incidence of chronic lung disease. CONCLUSIONS: High-frequency jet ventilation acutely improves oxygenation and ventilation without significantly increasing morbidity. Therefore high-frequency jet ventilation may be a useful adjunct for stabilization of the conditions of neonates with severe persistent pulmonary hypertension. Conclusions about the efficacy of high-frequency jet ventilation in improving survival without the need for extracorporeal membrane oxygenation await multicentered, collaborative investigations with large cohorts of patients.

Analysis of Variance↗