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PubMed1993

Predictive testing for Huntington's disease: after the gene. The United Kingdom Huntington's Disease Prediction Consortium.

The discovery of a mutation responsible for Huntington's disease (HD) offers the possibility of accurate predictive testing, as well as hope for treatment or prevention of this disease. We urge caution in the use of this new test as considerable ethical and counselling problems still exist, and new issues have arisen. The current guidelines for predictive testing should still apply, since it remains vital that subjects and their families have time to come to terms with the diagnosis of HD, and the implications of testing. Mutation analysis may allow the diagnosis of HD in isolated cases, or reverse a test result produced using linkage. Problems will arise as those at 25% risk may now receive a result despite the lack of support of their parent at 50% risk who may not wish to have their own status defined. In addition, couples who seek the exclusion test in pregnancy may find it difficult to investigate the pregnancy without producing information on themselves. Different centres should cooperate in maintaining the confidentiality of family members, ensuring that adequate counselling is given before results are produced which may affect the wider family.

Family↗

PubMed2003

Predicting outcome in ischemic stroke: external validation of predictive risk models.

BACKGROUND: Six multivariable models predicting 3-month outcome of acute ischemic stroke have been developed and internally validated previously. The purpose of this study was to externally validate the previous models in an independent data set. SUMMARY OF REPORT: We predicted outcomes for 299 patients with ischemic stroke who received placebo in the National Institute of Neurological Disorders and Stroke rt-PA trial. The model equations used 6 acute clinical variables and head CT infarct volume at 1 week as independent variables and 3-month National Institutes of Health Stroke Scale, Barthel Index, and Glasgow Outcome Scale as dependent variables. Previously developed model equations were used to forecast excellent and devastating outcome for subjects in the placebo tissue plasminogen activator data set. Area under the receiver operator characteristic curve was used to measure discrimination, and calibration charts were used to measure calibration. The validation data set patients were more severely ill (National Institutes of Health Stroke Scale and infarct volume) than the model development subjects. Area under the receiver operator characteristic curves demonstrated remarkably little degradation in the validation data set and ranged from 0.75 to 0.89. Calibration curves showed fair to good calibration. CONCLUSIONS: Our models have demonstrated excellent discrimination and acceptable calibration in an external data set. Development and validation of improved models using variables that are all available acutely are necessary.

Aged↗

PubMed1995

Time series prediction of plasma hormone concentration. Evidence for differences in predictability of parathyroid hormone secretion between osteoporotic patients and normal controls.

Recent evidence links osteoporosis, a disease of bone remodeling, to changes in the dynamics of parathyroid hormone secretion. We use nonlinear and linear time series prediction to characterize the secretory dynamics of parathyroid hormone in both healthy human subjects and patients with osteoporosis. Osteoporotic patients appear to lack the periods of high predictability found in normal humans. Our results may provide an explanation for why an intermittent administration of parathyroid hormone is effective in restoring bone mass in osteoporotic patients.

Adult↗

PubMed1987

Can the failure of a below-knee amputation be predicted? Predictability of below-knee amputation healing.

The predictability of below-knee amputation healing was evaluated in 69 patients with severe distal ischaemia with or without diabetes mellitus. A special attempt was made to find out predictors of amputation failure. Of 71 amputations performed 20 failed. Preoperative systolic blood pressures and skin perfusion pressures were significantly higher at the level of amputation in patients whose amputations healed than in those whose amputations failed, mean 69.5 (SD 33.4) mmHg and 55.9 (SD 27.0) mmHg vs. 41.5 (SD 31.6) mmHg (p less than 0.01) and 35.6 (SD 13.9) mmHg (p less than 0.05), respectively. There was, however, considerable overlapping and only if calf systolic blood pressure was unmeasurable did below-knee amputations always fail. PVR and skin perfusion pressure data were useful in disclosing falsely high calf systolic blood pressures apparently caused by mediasclerosis. When these patients with pseudohypertension were excluded the presence of diabetes did not affect the pressure readings. The blood viscosity as indicated in this study by pre- and postoperative haemoglobin levels did not affect amputation healing. The present results suggest that vascular laboratory data are useful as supplementary information in the assessment of below-knee amputation healing but it can predict amputation failure only when no Doppler signals are present at the ankle level.

Adult↗

PubMed1980

Prediction of dosage of lithium carbonate: use of a standard predictive method.

The nomogram developed by Cooper and associates used to predict the dose of Lithium Carbonate (Li+) which is needed to attain therapeutic Li+ concentrations has, in general, proven to be accurate and clinically useful. However, there may be some patients in whom the pharmacokinetic disposition of Li+ varies sufficiently so that accurate dosage predictions cannot be made; a report of one such patient is given.

Bipolar Disorder↗

PubMedDate not supplied

[The prediction of postoperative septic complications by means of nutritional parameters. II. The verification of the predictive formula].

An assessment was made of the predictive capacity of the following predictive formulation named Nutritional Sepsis Risk: NSR = 14.26 - 1.76 (albumin) - 1.47 (risk area) This was done in a sample of 65 surgery patients with digestive pathology who were candidates for selective surgery. All had undergone a pre-operative nutritional evaluation program, based on anthropometric and analytical data and Retarded Hypersensitivity Cutaneous Tests (RHCT). NSR was calculated pre-operatively. Infections were assessed qualitatively and quantitatively using Elebeute and Stoner's sepsis index. There were a total of five post-operative infections (7.69%). The NSR intersection point was calculated with an ROC curve, situated in a score of 3. The NSR detected the five infections, so is 100% sensitive, with 70% specificity and, in the detection of the septic risk population, surpassed the other nutritional parameters, whether anthropometric or analytical, and the RHCTs, when they were studied individually.

Aged↗

PubMed2003

Prediction rules for computed tomography in the dementia assessment: do they predict clinical utility of CT?

Neuroimaging is widely employed in the dementia assessment in refining clinical decision-making. However, with rising interest in cost-effective medical practice, efforts have been made in the literature to define clinical prediction rules that select for a subgroup of patients who would most likely benefit from neuroimaging. This short study examined the ability of a group of published clinical predictors to identify patients whose diagnoses or management would be influenced by CT scan results. The study finds that none of the published predictors bears a significant relationship to actual influence of CT scans in a group of memory clinic patients, highlighting the need for the development of clinical predictors for neuroimaging that will impact patient care.

Aged↗

PubMed2001

Duplication of CYP2D6 predicts high clearance of desipramine but high clearance does not predict duplication of CYP2D6.

OBJECTIVE: Duplication of CYP2D6 causes very rapid metabolism of CYP2D6 substrates such as desipramine. However, we have previously shown that in the Danish population, only about 15% of very rapid metabolisers, defined as subjects with a metabolic ratio of sparteine of 0.15 or less, carried a duplicated allele. The question is whether gene duplication is a relatively rare cause (perhaps predictor) of very rapid metabolism or whether a low metabolic ratio is a poor predictor of this. METHODS: After measuring metabolic ratios anew, we selected six volunteers with duplication of CYP2D6 and metabolic ratios ranging from 0.07 to 0.17 and six volunteers without duplication with metabolic ratios ranging from 0.08 to 0.21. Each subject took 100 mg of desipramine. Blood and urine were collected for 48 h. RESULTS: The median total oral clearance of desipramine was 372 l/h and 196 l/h [median difference 108 l/h (95.9% c.i., -304-598 l/h)] and the median partial clearance of desipramine by 2-hydroxylation was 155 l/h and 87 l/h [median difference 47 l/h (95.9% c.i., -124-141 l/h)] for the group with duplication and the group without duplication, respectively. CONCLUSION: The predictive value of duplication of CYP2D6 is poor; there must be other causes (or predictors) of very rapid metabolism and with much higher frequency than duplication of CYP2D6.

Administration, Oral↗

PubMed2003

Elevated troponin T and C-reactive protein predict impaired outcome for 4 years in patients with refractory unstable angina, and troponin T predicts benefit of treatment with abciximab in combination with PTCA.

AIMS: Treatment with the glycoprotein IIb/IIIa receptor antagonist abciximab before and during coronary intervention in refractory unstable angina improves early outcome. We collected 4-year follow-up data to assess whether this benefit is sustained. Additionally, we investigated the predictive value of baseline troponin T and CRP for long-term cardiovascular events. METHODS AND RESULTS: Of 1265 patients enrolled in the CAPTURE trial follow-up was available in 94% of the patients alive after 6 months (median 48 months). Survival was similar in both groups. Both elevated troponin T and CRP were associated with impaired outcome, independently of other established risk factors, but with a different time course. Elevated troponin was associated with increased procedure related risk, and elevated CRP with increased risk for subsequent events. Lower rates of the composite end-point of death or myocardial infarction with abciximab vs. placebo were sustained during long-term follow up: 15.7% vs 17.2% at 4 years (P=ns), particularly in patients with elevated troponin T: 16.9% with abciximab vs 28.4% with placebo: P=0.015. Elevated CRP was not associated with specific benefit of abciximab. CONCLUSION: Troponin T as a marker of thrombosis and CRP as a marker of inflammation are independent predictors of impaired outcome at 4 years follow-up. The initial benefit from abciximab with regard to death and myocardial infarction was preserved at 4 years. No specific benefit with abciximab was observed for patients with elevated CRP, suggesting that a chronic inflammatory process is not affected by abciximab. In contrast the benefit of treatment in patients with elevated troponin T implies that the acute thrombotic process in refractory unstable angina is treated effectively.

Abciximab↗

PubMedDate not supplied

Implementing a predictive modeling program, part II: Use of motivational interviewing in a predictive modeling program.

This is the second article of a two-part series about issues encountered in implementing a predictive modeling program. Part I looked at how to effectively implement a program and discussed helpful hints and lessons learned for case managers who are required to change their approach to patients. In Part II, we discuss the readiness to change model, examine the spirit of motivational interviewing and related techniques, and explore how motivational interviewing is different from more traditional interviewing and assessment methods.

Anger↗

PubMed1992

Prediction of difficult laryngoscopy: an assessment of the thyromental distance and Mallampati predictive tests.

Two hundred and fifty patients were assessed preoperatively using the Mallampati classification and by measuring their thyromental distances. The ease or difficulty of direct laryngoscopy was assessed at the time of induction of anaesthesia. Retrognathia was seen in 15.6% of patients and the incidence of difficult laryngoscopy without external laryngeal pressure was 8.2%. It was found that both assessments predicted less than two in three difficult laryngoscopies and had high false positive rates. It was found that external laryngeal pressure often improved the view of the glottis in difficult laryngoscopies.

Adolescent↗

PubMed1997

Predicting treatment attendance and weight loss: assessing the psychometric properties and predictive validity of the Dieting Readiness Test.

The Dieting Readiness Test (DRT) has been recommended by the Institute of Medicine as a measure of diet and exercise-related motivation and attitudes in those about to embark on a weight loss program. However, little research is available regarding the psychometric properties of this instrument. We conducted a study to assess the psychometric properties and predictive validity of the DRT. A group of 410 obese adults seeking outpatient treatment at a university-based weight management center completed the DRT prior to engaging in a comprehensive medically monitored program. Principal-components factor analysis indicated a five-factor solution and acceptable internal consistency for the resulting scales. The Bingeing and Eating cues scale was negatively associated with program attendance. None of the four remaining scales correlated with either attendance or weight loss. We conclude that although the DRT possesses a stable and interpretable structure and adequate internal consistency, it does not appear to be a strong predictor of weight loss or treatment attendance.

Adult↗

PubMed2002

Predicting survival of lung transplantation candidates with idiopathic interstitial pneumonia: does PaO(2) predict survival?

OBJECTIVE: To find a parameter that would discriminate between the patients with idiopathic interstitial pneumonia who survived to undergo transplantation and those who died while waiting to undergo transplantation. METHODS: A retrospective review was performed of all lung transplant referrals for idiopathic interstitial pneumonia that were listed with United Network for Organ Sharing at the University of California San Diego from January 1990 to February 1999. Of the 331 patients who were listed, 48 met the eligibility criteria. Patient demographics, radiographic studies, pathology reports, and the results of resting and exercise cardiopulmonary function tests were recorded from each patient's chart. Patients were divided into the following two groups: those patients who survived until transplantation and those still waiting were classified as "alive"; and those patients who died before undergoing transplantation were classified as "deceased." RESULTS: Forty-three of 48 patients had a pathologic diagnosis. The cohort included 25 patients with usual interstitial pneumonitis, 3 patients with nonspecific interstitial pneumonitis, 1 patient with desquamative interstitial pneumonitis, and 14 patients with interstitial lung disease of unknown etiology. The only significant difference between the two groups was resting PaO(2) (p = 0.035). A stepwise multivariate analysis demonstrated that PaO(2) and FEV(1)/FVC ratio were significantly associated with survival (hazards ratio, 1.06; confidence interval, 0.99 to 1.13; p = 0.019). CONCLUSIONS: A survival analysis using PaO(2) and FEV(1)/FVC ratio values proved to be statistically significant, but a prospective trial is needed to determine the clinical relevance of these parameters for predicting survival in patients with idiopathic interstitial pneumonia.

Adult↗

PubMed2004

Evaluation of Staphylococcus aureus growth potential in ham during a slow-cooking process: use of predictions derived from the U.S. Department of Agriculture Pathogen Modeling Program 6.1 predictive model and an inoculation study.

The U.S. Department of Agriculture has cautioned against slow cooking meat such that the interior temperature increases from 10 degrees C (50 degrees F) to 54.4 degrees C (130 degrees F) in > or = 6 h. During a commercial ham-smoking process, the ham cold point is typically between 10 and 54.4 degrees C for 13 h, but the ham is subsequently exposed to heating sufficient to eliminate vegetative pathogenic bacteria. Thus, production of heat-stable staphylococcal enterotoxin is the primary biological hazard. For this study, uncooked surface and uncooked ground interior ham were inoculated with a three-strain Staphylococcus aureus mixture, exposed to simulated surface and interior slow-cook conditions, respectively, and analyzed periodically using the Baird-Parker agar and 3M Petrifilm Staph Express count plate methods. For the surface and interior conditions, S. aureus numbers increased by no more than 0.1 and 0.7 log units, respectively. Predictions derived from actual time and temperature data and S. aureus growth values from a computer-generated model (Pathogen Modeling Program 6.1, U.S. Department of Agriculture) were for 2.7 (ham surface) and 9.9 to 10.5 (ham interior) generations of S. aureus growth, indicating that use of model-derived growth values would not falsely indicate safe slow cooking of ham. The Baird-Parker method recovered significantly (P < 0.05) greater numbers of S. aureus than the Petrifilm Staph Express method. For hams pumped with brine to attain (i) 18% (wt/wt) weight gain, (ii) > or = 2.3% sodium lactate, (iii) > or = 0.8% sodium chloride, and (iv) 200 ppm ingoing sodium nitrite, slow-cooking critical limits of < or = 4 h between 10 and 34 degrees C, < or = 5 h between 34 and 46 degrees C, and < or = 5 h between 46 and 54.4 degrees C could be considered adequate to ensure safety.

Animals↗

PubMedDate not supplied

[A possibility to predict the severity of individual damage following the exposure to supralethal radiation dosage. Prediction of working capacity of irradiated rats and dogs by response to pre-exposure physical load].

The experiments on rats and dogs exposed to radiation doses which cause intestinal and cerebral forms of radiation sickness have shown that, within the first 24 hours post-exposure, efficiency impairment can be predicted by changes in some indices of the cardiovascular and endocrine systems after physical load used as a non-radiation testing agent. The goodness of fit of experimental data to the expected result is up to 50-70%, still rising if a number of indices for different sections of the neuroendocrine system are used at a time.

Animals↗

PubMedDate not supplied

[A possibility to predict the severity of individual damage following the exposure to supralethal radiation dosage. Prediction of the clinical manifestation of radiation injury in laboratory animals by response to pre-exposure hypobaric hypoxia].

The experiments on rats, dogs and monkeys exposed to radiation doses which cause intestinal and cerebral forms of radiation sickness have shown that the severity of a clinical state can be predicted by cardiovascular and endocrine changes when a pre-exposure test with moderate hypobaric hypoxia is performed. The goodness of fit of experimental data to the exposed result is up to 60-80%, still rising if a set of indices of the neuroendocrine status is used.

Animals↗

PubMed1998

Describing patients' normal tissue reactions: concerning the possibility of individualising radiotherapy dose prescriptions based on potential predictive assays of normal tissue radiosensitivity. Steering Committee of the BioMed2 European Union Concerted Action Programme on the Development of Predictive Tests of Normal Tissue Response to Radiation Therapy.

Clinical radiotherapeutic doses are limited by the tolerance of normal tissues. Patients given a standard treatment exhibit a range of normal tissue reactions, and a better understanding of this individual variation might allow for individualisation of radiotherapeutic prescriptions, with consequent improvement in the therapeutic ratio. At present, there is no simple way to describe normal tissue reactions, which hampers communication between clinic and laboratory and between groups from different centres. There is also no method for comparing the severity of reactions in different normal tissues. This arises largely because there is no definition of a "normal" reaction, an "extreme" reaction or the particular term "over-reactor" (OR). This report proposes definitions for these terms, as well as a simple terminology for describing normal tissue reactions in patients having radiotherapy. The "normal" range represents the individual variation in normal tissue reactions amongst large numbers of patients treated in the same way which is within clinically acceptable limits. The term "OR" is applied to an individual whose reaction is more severe than the normal range but also implies that this forced a major change in the radiotherapeutic prescription or that the reactions were very severe or fatal. A "severe OR" would develop serious problems with a typical radical dose, while an "extreme OR" would have such difficulties at a much lower dose. To describe the normal range, a numerical scale is suggested, from 1 to 5, resistant to sensitive. The term "highly radiosensitive" (HR) is suggested for category 5. An "informal" relative scale, as suggested here, is quick and simple. It should allow comparison between different hospitals, compensate for differences in radiotherapeutic dose and technique and allow comparison of reactions between different anatomical sites. It should be adequate for discriminating patients at the extremes of the normal range from those at the centre. It is hoped that the definitions and terminology proposed here will aid communication in the field of predictive testing of normal tissue radiosensitivity.

Follow-Up Studies↗

PubMed1982

Prediction of remission in adult acute leukemia: development and testing of predictive models.

Logistic regression methods were applied to derive a set of models relating achievement of CR to prognostic characteristics in a group of 300 adult acute leukemia patients treated with cytosine arabinoside, vincristine, and prednisone combined with adriamycin (ADOAP) or rubidazone (ROAP). These models were tested prospectively in an independent group of 107 subsequent patients treated with ADOAP or ROAP therapy, by comparing observed outcomes to predictions of response based on the models. Several models were able to identify subgroups of patients with good, intermediate, and poor prognoses. A model regarded as clinically useful and which provided a good fit to both the population from which it was derived and the test population included the pretreatment factors age, history of an antecedent hematologic disorder, temperature, blood urea nitrogen, hemoglobin, and liver size.

Acute Disease↗