Biomedical subjects

M Leaning

Publications and source records attributed to M Leaning.

7 recordsLinked to original sources

PubMed1999

Prediction of the international normalized ratio and maintenance dose during the initiation of warfarin therapy.

AIMS: A pharmacokinetic/pharmacodynamic model, with Bayesian parameter estimation, was used to retrospectively predict the daily International Normalized Ratios (INRs) and the maintenance doses during the initiation of warfarin therapy in 74 inpatients. METHODS: INRs and maintenance doses predicted by the model were compared with the actual INRs and the eventual maintenance dose. Cases with drugs or medical conditions interacting with warfarin or receiving concurrent heparin therapy were not excluded. As the study was retrospective, model predictions of the maintenance dose were not those that were administered. Mean prediction error (MPE) and percentage absolute prediction errors (PAPE) were used to assess the model predictions. RESULTS: INR MPE ranged from -0.07 to 0.06 and median PAPE from 10% to 20%. Dose MPE ranged from -0.7 to 0.17 mg and median PAPE from 16.7% to 37.5%. Accurate and precise dose predictions were obtained after 3 or more INR feedback's. CONCLUSIONS: This study shows that the model can accurately predict daily INRs and the maintenance dose in this sample of cases. The model can be incorporated into computer decision-support systems for warfarin therapy and may lead to improvement in the initiation of warfarin therapy.

Adult↗

PubMed1997

Evaluation of a decision support system for initiation and control of oral anticoagulation in a randomised trial.

OBJECTIVE: To determine whether a computerised decision support system for initiation and control of oral anticoagulant treatment improves quality of anticoagulant control achieved by trainee doctors. DESIGN: Randomised controlled trial. SETTING: District general hospital in North London. SUBJECTS: 148 inpatients requiring start of warfarin treatment. INTERVENTIONS: Management by trainee doctors (to achieve therapeutic range of international normalised ratio of 2 to 3) with indirect assistance from computerised decision support system (intervention group) or without such assistance (control group). MAIN OUTCOME MEASURES: Median time to therapeutic range, stable dose, and first pseudoevent (excessive international normalised ratio after therapeutic range has been reached) and person time spent in the therapeutic range. RESULTS: 72 patients were randomised to the intervention group and 76 to control group. Median time to reach international normalised ratio of > or = 2 was not significantly different in the two groups (3 days). Median time to achieve a stable dose was significantly lower in intervention group than in controls (7 days v 9 days, P = 0.01) without excessive overtreatment or undertreatment with anticoagulant. Patients in intervention group spent greater proportion of time in therapeutic range, both as inpatients (59% v 52%) and outpatients (64% v 51%). CONCLUSION: The computerised decision support system was safe and effective and improved the quality of initiation and control of warfarin treatment by trainee doctors.

Administration, Oral↗

PubMed1997

Comparison of oral anticoagulant control by a nurse-practitioner using a computer decision-support system with that by clinicians.

With increasing work-loads in anticoagulant clinics different methods of service delivery need evaluation. The quality of anticoagulant control achieved by a nurse-practitioner using a computer decision-support system (CDSS) was compared with that achieved by trainee doctors without CDSS. Eighty-one out-patients (group A, therapeutic range 2-3) and 96 out-patients (group B, therapeutic range 3-4.5) were randomized to management by a nurse-practitioner or by trainee doctors (clinicians). Thirty-seven patients in group A and 50 patients in group B were randomized to be managed by the nurse-practitioner. In group A, patients in the nurse-practitioner group spent a longer time in the therapeutic range than those in the clinician group (60.7% compared with 51.6%). Dose suggestion acceptance in the nurse-practitioner group (88%) was higher compared with agreement between the CDSS and the clinicians (60%). In group B, patients in the clinician group spent a slightly longer time in the therapeutic range (70% compared with 67.6%). Acceptance of dose suggestion was lower in the nurse-practitioner group (67%) compared with agreement between the CDSS and the clinicians (73%). In conclusion, the CDSS can improve the quality of control of warfarin therapy by a nurse-practitioner over that by trainee doctors for the therapeutic range 2-3. Similar quality of control is achieved for the therapeutic range 3-4.5. The CDSS may be used by nurse-practitioners to achieve safe and effective anticoagulation in hospital-based or out-reach anticoagulant clinics.

Administration, Oral↗

PubMed1996

A prototype computer decision support system for the management of asthma.

Asthma is a chronic disease estimated to affect 6-7% of the total UK population. In addition, a number of studies have shown that asthma has become commoner since the 1970s, especially in children. The diagnosis of asthma can be difficult and its management requires the involvement of patients in a long-term treatment plan, something which general practitioners may be unable to achieve easily in the average 10-min consultation. As a consequence, asthma is underdiagnosed and undertreated. Deaths from the disease are often avoidable with timely and sufficient use of the available medication. In order to support this, the British Thoracic Society (BTS) has published guidelines for asthma management based upon a stepwise approach, in which a patient is categorized as being on one of five steps according to the severity of his or her asthma. The guidelines give "rules of thumb" for deciding when the patient should move up or down the steps. The most recent version of the guidelines also included special rules for children. Within a recent European Community project on Advanced Informatics in Medicine (AIM), we developed a prototype decision support system for asthma management targeted at the primary care setting and based on the British Thoracic Society guidelines. This paper reports this development, and describes the further work needed on the prototype. Plans for evaluation of the knowledge bases and for future full application production are also described.

Artificial Intelligence↗

PubMed1994

GAMES II Project: a general architecture for medical knowledge-based systems.

GAMES II aims at developing a comprehensive and commercially viable methodology to avoid problems ordinarily occurring in KBS development. GAMES II methodology proposes to design a KBS starting from an epistemological model of medical reasoning (the Select and Test Model). The design is viewed as a process of adding symbol level information to the epistemological model. The architectural framework provided by GAMES II integrates the use of different formalisms and techniques providing a large set of tools. The user can select the most suitable one for representing a piece of knowledge after a careful analysis of its epistemological characteristics. Special attention is devoted to the tools dealing with knowledge acquisition (both manual and automatic). A panel of practicing physicians are assessing the medical value of such a framework and its related tools by using it in a practical application.

Artificial Intelligence↗

PubMed1992

Inform: conceptual modelling of intensive care information systems.

Intensive care of a patient requires heavy monitoring and versatile therapeutic actions. These produce a huge amount of patient information. A problem exists in managing this data and other information from all supporting activities creating a need for an automated information management system. To have a sound basis for future automated information systems in intensive care unit (ICU), a conceptual model is created to cover both the clinical and other activities of the ICU. The conceptual model consists of data flow diagrams and entity-relationship diagrams with underlying common data dictionary. A modern CASE tool is utilized to build the model. The work forms a part of AIM-INFORM project, which has a purpose to develop information management and decision support systems for high dependency environment.

Computer Simulation↗

PubMed1985

The effects of diabetes and insulin on glycoprotein metabolism by rat liver.

The hepatic metabolism of [125I]agalactoorosomucoid [( 125I]AGOR) was studied in normal and streptozotocin-induced diabetic rats. The blood clearance, hepatic transport time and rate of catabolism of [125I]AGOR were calculated from data of the blood [125I]AGOR disappearance rates and the appearance in blood of acid-soluble catabolites. In control rats the blood clearance of [125I]AGOR was rapid (8.7 +/- 0.6 ml/min) and the hepatic transport time of the ligand was 12.8 +/- 0.7 min. Insulin prolonged the hepatic transport time (18.1 +/- 1.9 min) and depressed ligand catabolism. Chloroquine had similar effects. Diabetes impaired hepatic [125I]AGOR uptake as judged by the prolonged blood clearance rate and depressed ligand catabolism but did not alter ligand transport time. The measured parameters returned to normal when diabetic animals were rendered acutely normoglycaemic. Diabetic rats, in which implanted osmotic insulin pumps had maintained normoglycaemia for 3 days, cleared [125I]-AGOR from the blood more rapidly than controls. This effect appeared to be due to the lower blood glucose levels in this group. The experiments have shown the complexity of the effects of insulin and diabetes mellitus on the uptake and processing of a glycoprotein by the hepatic mannose receptor.

Animals↗