The Effect of Legal and Hospital Policies on Physician Response to Prenatal Substance Exposure

Objectives: To determine the influence of a state's legal environment and a hospital's Prenatal Substance Exposure (PSE) protocol on physicians' propensity to respond when prenatal substance exposure is suspected. Methods: Using a sample of 1367 physicians from every state and the District of Columbia, we formulate a set of linear models to determine the impact of the legal environment and hospital protocol on physicians' response to PSE, the agreement between physicians' perceptions and actual state legal environments, and physicians' motivation to act when PSE is suspected. Results: Both protocol and legal environment showed to be significantly correlated with physicians' propensity to take action when PSE is suspected (p < 0.05). Our analysis shows that physicians prefer a public health (patient-centered) approach to more punitive measures. Conclusions: Our results suggest a policy strategy focused first on enacting laws that would encourage a patient-centered approach, by developing and using hospital protocols to implement state policy, and then on educating physicians about the actual legal environment.     

Hierarchical Generalised Linear Models with Time-Dependent Clustering: Assessing the Effect of Health Sector Reform on Patient Outcomes in New Zealand

New Zealand has one of the most reformed health systems in the world. This paper is primarily concerned with modelling the impact on hospital outcomes of the reforms of the early 1990s, when as part of a major, health sector wide reform process, the administration of public hospitals passed from elected Area Health Boards (AHBs) to Crown Health Enterprises (CHEs) operating under a competitive model of health care provision dominated by the funder/purchaser/provider split. The impact of reform processes on public hospitals is of particular interest since they consume 40%–50% of public expenditure on health, and have been repeatedly restructured in an attempt to contain the ever-expanding cost of health care. There is concern among both health professionals and the general public that these restructurings are reducing the quality of hospital services, and therefore negatively effecting patient outcomes. Using data from a study of 34 New Zealand public hospitals, we discuss the application of Bayesian hierarchical generalised linear models to the analysis of trends in patient outcomes over the period 1988–2001. The time-varying nature of the grouping of hospitals within larger health authorities complicates the application of HGLMs because the cluster structure of the data changes over the study period. An approach to dealing with such time-dependent clustering by introducing period-specific authority level effects is developed. The analysis does not support the proposition that higher level authorities had an effect on outcome trends, or that the administrative changeover from AHBs to CHEs impacted on 60-day post-admission mortality.     

Movement discrimination by single cells in the human pallidum characterised by hidden Markov models

In patients undergoing pallidotomy for Parkinson's disease, we recorded extracellularly from single neurons in the two internal segments (GPii, GPie) and the external segment (GPe) of the globus pallidus (GP) in response to active (cued) movements of the contralateral wrist, elbow or ankle. The patterns of cell activity occurring both before and after movement onset were analysed using hidden Markov models (HMMs) and clustered by movement type using the generative topographical mapping algorithm. Cluster separation was quantified in order to measure a cell's ability to discriminate between movements. Statistical analysis of variance indicated a significant regional gradient (GPii > GPie > GPe) of movement discrimination, while cells in all regions differentiated better between movements of different joints (wrist, elbow or ankle) than between flexion and extension of the same joint. We found that GP cells generally showed distinguishable firing patterns corresponding to more than one type of movement per cell, in support of the hypothesis that cells in these regions of the basal ganglia are not involved in preparation or execution of a single type of movement but participate in many different movements, analogous to the hidden units of a neural network. Our results also indicate that cell activity both preceding a movement and during its execution may be modelled by HMMs with only a small number of states.     

Insulin secretion rate during glucose stimuli: alternative analyses of C-peptide data

The ability to evaluate the pancreatic insulin secretion rate (ISR) is essential for a quantitative understanding of the glucose regulation system in man. Various approaches have been developed for evaluation of the ISR in vivo. The aim of this study was to compare input/output and compartmental models of C-peptide to reconstruct the ISR in response to both physiological and nonphysiological glucose stimuli in healthy humans. In particular we applied the nonparametric stochastic deconvolution and the C-peptide minimal model approaches to the graded up&down glucose infusion protocol, where glucose was infused at progressively increasing and then decreasing rates, and to the intravenous glucose tolerance test (IVGTT), where an impulse dose of glucose was administered. Our results show that the two models give virtually identical results when glucose and C-peptide (and thus ISR) profiles are smooth and regular, but when vigorous nonstationarities are present, like during the first 4 min of the IVGTT, the two ISR profiles are different (but not their areas under the curve). The C-peptide minimal model, albeit requiring, at variance with deconvolution, the knowledge of glucose data, has the advantage of providing quantitative indices of the -cell function, which is important in the parametric definition of different physiopathological states. © 2001 Biomedical Engineering Society. PAC01: 8715Rn, 8714Ee, 8716Ac     

Providing wholistic health care for the elderly: utilization of the Shuler Nurse Practitioner Practice Model

PURPOSE: To present an application of The Shuler Nurse Practitioner Practice Model with elderly patients through use of a gerontological wholistic assessment and the utilization of the model in developing a treatment plan and evaluating patient outcomes. DATA SOURCES: Selected literature from nursing and medicine, including natural, alternative, and complementary (NAC) therapies, as well as the authors' personal experiences. CONCLUSIONS: Providing health care services to the elderly involves recognition of not only physical ailments, but also an awareness of how functional status, psychological condition, social support, environmental conditions and cultural, as well as spiritual beliefs, shape the total health care needs of this vulnerable group. IMPLICATIONS FOR PRACTICE: Nurse practitioners who work with the aged could benefit from a theoretically based, wholistic assessment guide. Treatment plans that include NAC therapies and healing strategies should be considered. Outcome evaluations should reflect adherence to the elders' preferences regarding quality and end-of-life issues.     

Predictive performance of computer-controlled infusion of remifentanil during propofol/remifentanil anaesthesia

Background. The predictive performance of the available pharmacokineticparameter sets for remifentanil, when used for target-controlledinfusion (TCI) during total i.v. anaesthesia, has not been determinedin a clinical setting. We studied the predictive performanceof five parameter sets of remifentanil when used for TCI ofremifentanil during propofol anaesthesia in surgical patients. Methods. Remifentanil concentration–time data that hadbeen collected during a previous pharmacodynamic interactionstudy in 30 female patients (ASA physical status I, aged 20–65 yr)who received a TCI of remifentanil and propofol during lowerabdominal surgery were used in this evaluation. The remifentanilconcentrations predicted by the five parameter sets were calculatedon the basis of the TCI device record of the infusion rate–timeprofile that had actually been administered to each individual.The individual and pooled bias [median performance error (MDPE)],inaccuracy [median absolute performance error (MDAPE)], divergenceand wobble of the remifentanil TCI device were determined fromthe pooled and intrasubject performance errors. Results. A total of 444 remifentanil blood samples were analysed.Blood propofol and remifentanil concentrations ranged from 0.5to 11 µg ml^–1 and 0.1 to 19.6 ng ml^–1respectively. Pooled MDPE and MDAPE of the remifentanil TCIdevice were –15 and 20% for the parameter set of Mintoand colleagues (Anesthesiology 1997; 86: 10–23), 1 and21%, –6 and 21%, and –6 and 19% for the three parametersets described by Egan and colleagues (Anesthesiology 1996;84: 821–33, Anesthesiology 1993; 79: 881–92, Anesthesiology1998; 89: 562–73), and –24 and 30% for the parameterset described by Drover and Lemmens (Anesthesiology 1998; 89:869–77). Conclusions. Remifentanil can be administered by TCI with acceptablebias and inaccuracy. The three pharmacokinetic parameter setsdescribed by Egan and colleagues resulted in the least biasand best accuracy. Br J Anaesth 2003; 90: 132–41     

Therapeutic perspectives for melatonin agonists and antagonists

Melatonin is a neurohormone synthesized in the pineal gland during the dark period in all species, including humans. The diversity and differences in melatonin receptor distribution in the brain and extracerebral organs suggest multiple functional roles for melatonin. Administration of melatonin agonists reduces neophobia and treatment with a melatonin antagonist during the dark period reverses the anxiolytic-like effect of endogenous melatonin. Chronic treatment with agonists prevents various perturbations induced by chronic mild stress. Melatonin in vivo directly constricts cerebral arterioles in rats and decreases the lower limit of cerebral blood flow autoregulation, suggesting that melatonin may diminish the risk of hypoperfusion-induced cerebral ischemia. At the extracerebral level, melatonin regulates intestinal motility in rats. The intestinal postprandial motor response is shorter in the dark phase than in the light phase and this reduction is reversed in animals pretreated with a melatonin antagonist. Moreover, melatonin reduces the duration of cholecystokinin excitomotor effect. Endogenous melatonin may modulate intestinal motility to coordinate intestinal functions such as digestion and transit and control the metabolism of the animal. An adipocyte melatonin binding site may also participate in this control. Melatonin is involved in a wide range of physiological functions. The question remains as to whether evolution, adaptation and diurnal life have modified the physiological role of melatonin in humans. Moreover, the functional role of each of the receptor subtypes has to be characterized to design selective ligands to treat specific diseases.     

Socioeconomic Disparities Are Negatively Associated with Pediatric Emergency Department Aftercare Compliance

OBJECTIVES: This study sought to identify demographic, socioeconomic, and clinical predictors of aftercare noncompliance by pediatric emergency department (ED) patients. METHODS: The authors conducted a prospective, observational study of pediatric patients presenting to a university teaching hospital ED from July 1, 2002, through August 31, 2002. Demographic and clinical information was obtained from guardians during the ED visit. Guardians were contacted after discharge to determine compliance with ED aftercare instructions. Subjects were excluded if they were admitted or if guardians were unavailable or unwilling to consent. Data were analyzed using multivariable logistic regression to identify predictors of noncompliance from a list of predetermined variables. RESULTS: Of the 409 patients enrolled in the study, 111 were prescribed medications and 364 were given specific follow-up instructions. Subtypes of the variable "insurance status" were significantly associated with medication noncompliance in multivariable regression analysis. "Insurance status" and "low-acuity discharge diagnoses" were significantly associated with follow-up noncompliance. CONCLUSIONS: Disparity in health insurance has been shown to be a predictor of poor aftercare compliance for pediatric ED patients within the patient population.     

The effect of variable health insurance deductibles on the demand for physician visits

In order to contain cost in the health care sector, the introduction of consumer incentives in health insurance has been suggested and realized in many countries. The Swiss health system reform of 1996 introduced a choice of deductible for health services in the mandatory basic health insurance. This paper estimates the effect of this choice on physician service utilization. A generalized method of moments (GMM) estimator is applied to take account of the endogeneity of the choice of the deductible in the estimation of the number of physician visits. This paper finds that most of the observed reduction in the number of physician visits among individuals who choose a higher deductible seems to be a result of self-selection of individuals into the respective insurance contracts, and not to induced changes in utilization behaviour.