Efficiency and cost saving of 7 day per week exercise testing utilizing all electrocardiography technologists.

BACKGROUND: In most centers, exercise testing (ET) is performed by one or two trained technologists during the weekdays (0800 hours-1600 hours), leaving a void during evenings and weekends. This leads to unnecessary increased costs due to delays in management of patients. Electrocardiography technologists (ECGT) are often available for extended hours. This project was undertaken to improve the efficiency of the ET laboratory by using ECGT to perform ET during these extended hours. METHODS: Clinical utility and cost saving of a 7 day per week ET for management of patients with suspected and/or known coronary artery disease utilizing ECGT was assessed after adequate training. Of 4099 patients undergoing ET between January 1995 and December 1997, 810 tests performed by ECGT were reviewed retrospectively. RESULTS: Of the 810 patients (age mean 58.4 +/- 0.44 yrs; range 16-88; males: 508, females: 302), 806 (99.5%) underwent the Bruce protocol. The indications were: diagnostic, 61.3%, predischarge acute myocardial infarction (AMI), 17.7%, evaluation of angina, 19.6%, other, 1.4%. Only 8 (0.1%) patients had complications (prolonged chest pain, 6; nonsustained ventricular tachycardia, 2) with no AMIs or deaths. This strategy resulted in a savings of 158 bed days (Can189,600 dollars) on inpatients and 15 bed days (Can18,000 dollars) on those presenting to the emergency department. CONCLUSIONS: This study demonstrates the feasibility and safety of utilizing ECGT for ET thus extending the hours of service. This resulted in efficient patient management, with a considerable cost-saving to the hospital.

Two-locus modeling of asthma in a Hutterite pedigree via Markov chain Monte Carlo.

Bayesian Markov chain Monte Carlo (MCMC) segregation analysis for asthma was performed on the whole 1,544-member Hutterite pedigree. Heterogeneous and epistatic two-locus models and complex one-locus models were investigated, with trait loci postulated to be linked to markers in regions previously found to be possibly linked to asthma or atopy. The epistatic two-locus dominant-dominant model provided the best estimates, among the models investigated, in terms of prediction of population prevalence and relative risk for sibs of the affected.

Higher-level phylogeny of the Therevidae (Diptera: insecta) based on 28S ribosomal and elongation factor-1 alpha gene sequences.

Therevidae (stilleto flies) are a little-known family of asiloid brachyceran Diptera (Insecta). Separate and combined phylogenetic analyses of 1200 bases of the 28S ribosomal DNA and 1100 bases of elongation factor-1alpha were used to infer phylogenetic relationships within the family. The position of the enigmatic taxon Apsilocephala Kröber is evaluated in light of the molecular evidence. In all analyses, molecular data strongly support the monophyly of Therevidae, excluding Apsilocephala, and the division of Therevidae into two main clades corresponding to a previous classification of the family into the subfamilies Phycinae and Therevinae. Despite strong support for some relationships within these groups, relationships at the base of the two main clades are weakly supported. Short branch lengths for Australasian clades at the base of the Therevinae may represent a rapid radiation of therevids in Australia.

Guidelines for pacemaker follow-up in Canada: a consensus statement of the Canadian Working Group on Cardiac Pacing.

A survey on Canadian pacing practices conducted in 1997 revealed a widespread desire for national guidelines on pacemaker follow-up. The present guidelines for pacemaker follow-up are a consensus statement of the Canadian Working Group on Cardiac Pacing. Direct patient follow-up rather than transtelephonic monitoring is desirable. Patients should be assessed at a minimum of within 72 h of implantation, at two to 12 weeks and at six months following implantation, and annually thereafter. More frequent assessments may be required for some patients. This depends on associated cardiovascular problems and specific devices. A typical follow-up visit should include a targeted cardiovascular assessment, interrogation of the pacing system, review of telemetered data, assessment of the underlying rhythm, assessment of pacing and sensing thresholds, and appropriate reprogramming of pacing parameters to optimize device function and longevity.

Mitigating epidemics caused by non-persistently transmitted aphid-borne viruses: the role of the pliant environment.

Using Soybean mosaic virus as a model system, the rate, magnitude and timing of epidemics caused by non-persistently transmitted, aphid-borne viruses are examined under various field conditions. Emphasis is placed on the behavioural responses of vectors to environmental cues, although all three biotic components (host plant, vector and virus) are considered. Both single and double manipulations of the cropping system environment are explored using a computer model developed earlier by Ruesink and Irwin (Plant Virus Epidemics: Monitoring, Modelling and Predicting Outbreaks.

Coupling Disease-Progress-Curve and Time-of-Infection Functions for Predicting Yield Loss of Crops.

ABSTRACT A general approach was developed to predict the yield loss of crops in relation to infection by systemic diseases. The approach was based on two premises: (i) disease incidence in a population of plants over time can be described by a nonlinear disease progress model, such as the logistic or monomolecular; and (ii) yield of a plant is a function of time of infection (t) that can be represented by the (negative) exponential or similar model (zeta(t)). Yield loss of a population of plants on a proportional scale (L) can be written as the product of the proportion of the plant population newly infected during a very short time interval (X'(t)dt) and zeta(t), integrated over the time duration of the epidemic. L in the model can be expressed in relation to directly interpretable parameters: maximum per-plant yield loss (alpha, typically occurring at t = 0); the decline in per-plant loss as time of infection is delayed (gamma; units of time(-1)); and the parameters that characterize disease progress over time, namely, initial disease incidence (X(0)), rate of disease increase (r; units of time(-1)), and maximum (or asymptotic) value of disease incidence (K). Based on the model formulation, L ranges from alphaX(0) to alphaK and increases with increasing X(0), r, K, alpha, and gamma(-1). The exact effects of these parameters on L were determined with numerical solutions of the model. The model was expanded to predict L when there was spatial heterogeneity in disease incidence among sites within a field and when maximum per-plant yield loss occurred at a time other than the beginning of the epidemic (t > 0). However, the latter two situations had a major impact on L only at high values of r. The modeling approach was demonstrated by analyzing data on soybean yield loss in relation to infection by Soybean mosaic virus, a member of the genus Potyvirus. Based on model solutions, strategies to reduce or minimize yield losses from a given disease can be evaluated.

A multiple locus analysis of the collaborative study on the genetics of alcoholism data set.

Parametric and nonparametric statistical methods have been applied to the alcohol dependence data set collected in the Collaborative Study on the Genetics of Alcoholism (COGA). Our nonparametric linkage analyses (NPL) were based on the S(all) statistic of GENEHUNTER [Kruglyak et al., 1996] and the improved NPL statistic of GENEHUNTER-PLUS [Kong and Cox, 1997]. Based on likely regions for alcohol susceptibility genes identified from our nonparametric analyses, we reanalyzed the data using several two-locus models. We used the TMLINK program [Lathrop and Ott, 1990] in the LINKAGE package for these parametric analyses.

Feasibility of direct discharge from the coronary/intermediate care unit after acute myocardial infarction.

OBJECTIVES: This investigation was designed to determine the feasibility and cost-effectiveness of direct discharge from the coronary/intermediate care unit (CICU) in 497 consecutive patients with an acute myocardial infarction (AMI). BACKGROUND: Although patients with an AMI are traditionally treated in the CICU followed by a period on the medical ward, the latter phase can likely be incorporated within the CICU. METHODS: All patients were considered for direct discharge from the CICU with appropriate patient education. The 6-week postdischarge course was evaluated using a structured questionnaire by a telephone interview. RESULTS: There were 497 patients (men = 353; women = 144; age 63.5 +/- 0.6 years) in the study, with 29 in-hospital deaths and a further 11 deaths occurring within 6 weeks of discharge. The mode length of CICU stay was 4.0 days (mean 5.1 +/- 0.2 days): 1 to 2 (12%), 3 (19%), 4 (21%), 5 (14%), 6 to 7 (19%) and > or = 7 (15%) days, respectively with 87.2% discharged home directly. Of the 425 patients surveyed, 119 (28.0%) indicated that they had made unscheduled return visits (URV) to a hospital or physician's office: 10.6% to an emergency room, 9.4% to a physician's office and 8.0% readmitted to a hospital. Of these URV, only 14.3% occurred within 48 h of discharge. Compared to historical controls, the present management strategy resulted in a cost savings of Cdn. $4,044.01 per patient. CONCLUSIONS: Direct discharge from CICU is a feasible and safe strategy for the majority of patients that results in considerable savings.

Cardiac pacing in Canada in 1998: working towards optimal pacing therapy. Canadian Working Group on Cardiac Pacing.

The Canadian Working Group on Cardiac Pacing (CWGCP) was formed in 1996 with the primary goal of promoting optimal pacing therapy in Canada. In 1997, the CWGCP conducted a survey of pacing practices across Canada. Ninety-two of 125 implanting programs (74%) responded. Implant rates vary by province--from 39 per 100,00 population in Ontario to 63 per 100,000 population in Nova Scotia and Prince Edward Island. Variations in regional implant rates persist even after correcting for the age of the population. Physiological pacing was used for 35% of all implants in Canada in 1996/97. There were marked differences across Canada in the mode of pacing selected. In western Canada, 39.5% of pacing systems implanted were physiological compared with 18.2% in Atlantic Canada and 29% in Quebec. There were also differences in follow-up practices. Approximately 40% of centres follow patients with single chamber pacemakers annually, whereas most other centres still follow these patients every six months. Economic constraints, the size of pacing programs and the involvement of committed pacing physicians are factors that may influence the regional differences in cardiac pacing across Canada.

NASPE expert consensus document: use of i.v. (conscious) sedation/analgesia by nonanesthesia personnel in patients undergoing arrhythmia specific diagnostic, therapeutic, and surgical procedures.

Use of IV (Conscious) Sedation/Analgesia by Nonanesthesia Personnel in Patients Undergoing Arrhythmia Specific Diagnostic, Therapeutic, and Surgical Procedures. This article is intended to inform practitioners, payers, and other interested parties of the opinion of the North American Society of Pacing and Electrophysiology (NASPE) concerning evolving areas of clinical practice or technologies or both, that are widely available or are new to the practice community. Expert consensus documents are so designated because the evidence base and experience with the technology or clinical practice are not yet sufficiently well developed, or rigorously controlled trials are not yet available that would support a more definitive statement. This article has been endorsed by the American College of Cardiology, October 1997.

An evaluation of a dentifrice containing salivary peroxidase elements for the control of gingival disease in patients with irradiated head and neck cancer.

Patients who have undergone irradiation for head and neck tumors commonly have xerostomia. Loss of the protective constituents normally found in saliva leaves patients at greater risk for development of significant dental pathologic disorders, including gingival and periodontal disease. Periodontal disease and tooth extractions are currently accepted as etiologic factors for the development of osteoradionecrosis. This double-blind crossover trial was conducted to assess the efficacy of a dentifrice containing salivary peroxidase elements in the reduction of gingivitis in a population of patients with irradiated cancer. Subjects were instructed to brush with the dentifrice provided. Plaque and gingival index values were obtained and statistically compared with baseline values. A weak positive effect was found between use of the dentifrice and a reduction in gingival inflammation. Patient compliance was a limiting factor in this treatment effect. The results suggest possible efficacy for the dentifrice in augmenting traditional measures of postradiation oral health maintenance.

Randomized controlled trial of selective bowel decontamination for prevention of infections following liver transplantation.

Nonabsorbable antibiotics for selective bowel decontamination (SBD) sometimes are administered to liver transplant patients to prevent postoperative infections, but the efficacy of SBD is not known. Accordingly, we prospectively studied 69 patients randomly assigned to receive conventional prophylaxis with systemic antibiotics (control patients) or conventional prophylaxis plus oral nonabsorbable antibiotics for SBD (SBD patients). Overall rates of bacterial and/or yeast infections were nearly equal among control patients (42%) and SBD patients (39%). However, the infection rate at SBD key sites (abdomen, bloodstream, surgical wound, and lungs) was lower among patients who received the SBD regimen > or = 3 days before transplantation (23%) than among control patients (36%). Administration of the SBD regimen was complicated by gastrointestinal intolerance and noncompliance but not by increased stool colonization with antibiotic-resistant gram-negative bacilli. Practical problems associated with administering an SBD regimen to patients awaiting cadaver liver transplants limit the regimen's usefulness, but we found a trend toward reduced key site infection when the regimen was given > or = 3 days before transplantation.

Report of the NASPE Policy Conference on antibradycardia pacemaker follow-up: effectiveness, needs, and resources. North American Society of Pacing and Electrophysiology.

On May 4-5, 1993, a policy conference was held in San Diego, California, under the sponsorship of the North American Society of Pacing and Electrophysiology (NASPE) to identify the fundamental goals of antibradycardia pacemaker follow-up, evaluate the effectiveness with which it achieves those goals, and formulate specific recommendations as to how it can be made more effective. The conference addressed clinical, administrative, and educational objectives, focusing on existing and potential resources for follow-up testing and the appropriate frequency of their application. The training of physicians and associated professionals engaged in follow-up also was addressed, as were regulatory and reimbursement issues. This report summarizes the conclusions and recommendations arrived at during the conference and subsequently approved by the NASPE Board of Trustees.

Outcomes of an ambulatory cardiac pacing program: indications, risks, benefits, and outcomes.

UNLABELLED: The purpose of this review was to evaluate the economical benefits and outcomes of an ambulatory pacing system implantation program that began in 1991 for new and replacement pacing system implantations. Patient access, incidence of complications, hospital bed day utilization, economic impact, safety, and practicality of the Ambulatory Pacing System Implantation Program was retrospectively reviewed from August 1991 to March 1994. The Ambulatory Pacing System Implantation Program includes pre-operative outpatient assessment in the pacemaker clinic, admission to the Day Medical Unit followed by same day pacing system implantation, discharge home after a short period of observation, and, in selected cases, cardiac monitoring, followed by pacemaker clinic visit 24-hours postimplantation. RESULTS: Two hundred four cardiac pacing systems, 154 new and 50 replacements (pulse generator/leads), were implanted under the guidelines of the Ambulatory Pacing System Implantation Program between August 1991 and March 1994. Eighty-seven percent of the patients were implanted with passive fixation leads, the remaining with active fixation leads; all but four of which were leads implanted in the atria. Preprocedure wait time was decreased from 16 to 2 days for elective pacing system implantation. The incidence of lead dislodgment in the first, second, and third year of the Ambulatory Pacing System Implantation Program was 20%, 12%, 5%, respectively; compared to 11% for a similar number of cases in previous years done as inpatients. The incidence of new infection was 2.4% compared to < 1% in previous years. Six of the 204 (2%) cases required admission overnight. A total savings of 1,456 bed days ($1,275,450.00; Canadian) has been realized for an equivalent number of cases when compared with previous years. The operational cost was reduced by $3,976.00 per case. CONCLUSION: It has been shown that the Ambulatory Pacing System Implantation Program has improved client access, and is a safe and economical approach to implantation of cardiac pacing systems.

Genetic studies on an Alzheimer clinic population.

All patients attending the Clinic for Alzheimer Disease and Related Disorders have detailed family histories taken by a geneticist. To date, genetic histories are available for 446 consecutive, unrelated individuals. Of these, 151 (33.9%) are diagnosed as having "probable" (N = 141) or "autopsy-confirmed" (N = 10) Alzheimer disease according to recognized criteria. This data base represents a relatively unselected population with respect to more than one person in the family having dementia. Seventy-one of these 151 index cases (47.0%) have a positive family history of dementia, of which 8 (5.3%) may represent the familial (autosomal dominant) form of Alzheimer disease (FAD). Age-corrected empiric recurrence risks for Alzheimer disease/dementia were calculated for first-degree relatives of these 151 index cases using the Kaplan-Meier lifetable method.