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PubMed1987

Disability as a predictor of outcome for the elderly in a department of internal medicine. A comparison of predictions based on index of ADL and physician predictions.

The predictive validity of ratings based on Katz' Index of ADL (Activities of Daily Living) and of physician ratings of patient outcome was studied in a department of internal medicine, 129 patients, 65 years of age or older, were assessed independently and simultaneously by licensed practical nurses using Katz' Index of ADL and by a physician using clinical judgement. These assessments were related to observed outcome regarding survival or death in the ward, length of stay, and type of hospital discharge. Two alternative ADL-groupings were used, grade A-E versus grade F-G and grade A-F versus grade G. Sensitivity and specificity of ADL-ratings and of physician ratings were found to be rather similar regarding length of stay less than 10 days and discharge to own home. Predictions regarding patient deaths based on ADL-grades F-G and G had a higher sensitivity than predictions based on physician ratings. The specificity of the two types of predictions was about the same. There was only a fair correlation between age and ADL-grade. ADL-assessments may thus be useful for planning purposes for elderly patients also in acute medical wards.

Activities of Daily Living↗

PubMed1986

Accuracy of a discriminant analysis model for prediction of coliform mastitis in dairy cows and a comparison with clinical prediction.

We tested an equation, which had been developed previously using discriminant analysis, for predicting whether a cow has coliform mastitis. Variables indicating a high probability of coliform infection included history of previous mastitis in the affected quarter, weakness, clear or white color of milk, water consistency of the milk, swelling of the udder, lack of previous mastitis in other quarters, lack of palpable udder abscesses, and a high body temperature. Application of this predictive equation to 114 cows with mastitis to determine if they would have coliform organisms cultured from the affected quarters resulted in an accuracy of 71% (sensitivity = 0.42, specificity = 0.85), compared to an accuracy of 62% (sensitivity = .64, specificity = .61) for cowside prediction by the attending clinicians. Changing the cutoff score of the discriminant rule so that the sensitivity of the discriminant prediction was similar to that of the clinicians yielded an accuracy of 64% (sensitivity = .64, specificity = .64).

Animals↗

PubMed1995

Astigmatism reduction clinical trial: a multicenter prospective evaluation of the predictability of arcuate keratotomy. Evaluation of surgical nomogram predictability. ARC-T Study Group.

OBJECTIVE: To determine the accuracy of the Lindstrom surgical nomogram for astigmatism. DESIGN: A prospective multicenter study. PATIENTS: One hundred sixty eyes of 95 patients underwent astigmatic keratotomy in eight centers by nine surgeons. Inclusion criteria for the study included age of at least 18 years with 1 to 6 diopters (D) of naturally occurring corneal astigmatism and less than 1 D of lenticular astigmatism. INTERVENTIONS: A standardized astigmatic keratotomy surgical technique was performed on each eye. Surgical measurements were determined using the Lindstrom surgical nomogram for astigmatism. MAIN OUTCOME MEASURE: The Holladay, Cravy, Koch vector analysis method was used to determine the change in refractive cylinder results. Refractive changes also are presented without vector analysis merely using the absolute change in refractive cylinder and axis. RESULTS: Multiple regression analysis was used to develop a mathematical model determining the factors predictive of the change in refractive cylinder. The significant predictors for the amount of astigmatic correction achieved were, in order of decreasing importance, the following: number of incisions (R2 = 30%), incision length (R2 = 16%), age (R2 = 8%), and gender (R2 = 2%). CONCLUSIONS: Astigmatism is a two-dimensional measurement of both quantity and direction that is most appropriately analyzed with vector analysis. The original Lindstrom surgical nomogram for arcuate keratotomy used in this study is still quite useful although it tended to underpredict results for many patients, especially those having two incisional surgeries. Some older subjects having minimal surgery achieved greater correction than predicted by the original nomogram. The most important factors predictive of greater astigmatic keratotomy surgical effect are incision number, incision length, older age, and male gender.

Adult↗

PubMed2006

Seizure prediction: the impact of long prediction horizons.

Several procedures have been proposed to be capable of predicting the occurrence of epileptic seizures. Up to now, all proposed algorithms are far from being sufficient for a clinical application. This is, however, often not obvious when results of seizure prediction performance are reported. Here, we discuss impacts of long prediction horizons with respect to clinical needs and the strain on patients by analyzing long-term continuous intracranial electroencephalography data.

Adolescent↗

PubMed2003

Prediction of Recurrent Events by D-Dimer and Inflammatory Markers in Patients with Normal Cardiac Troponin I (PREDICT) Study.

BACKGROUND: The independent predictive value of d-dimer and inflammatory markers for the risk of recurrent adverse events in patients with acute chest pain but normal levels of cardiac troponin I (cTnI) remains unclear. METHODS: We studied 391 patients admitted to the hospital in 1 year with acute ischemic-type chest pain. Creatine kinase-myocardial band isoenzyme (CK-MB) mass and cTnI levels were measured in initial and 12-hour samples. Soluble intercellular adhesion molecule (sICAM)-1, vascular cell adhesion molecule (sVCAM)-1, sP-selectin, sE-selectin, high sensitivity C-reactive protein (hsCRP), interleukin-6 (IL6), fibrinogen, and d-dimer levels were measured in initial samples. A 1-year incidence of death, myocardial infarction (MI), revascularization, or readmission with chest pain was determined (with death/MI as the primary end point). RESULTS: Patients with normal levels of CK-MB(mass) and cTnI (195/391[50%]) were at a lower risk than patients with elevated levels of CK-MB(mass) or cTnI, but still had an important incidence of events (77/195[39%]). Marker elevation was defined as >75th percentile (upper quartile). Elevated d-dimer levels (>580 ng/mL) was predictive of death/MI (odds ratio, 5.4; 95% CI, 1.5-20.2; P =.005). Elevated sP-selectin levels (>152 ng/mL; odds ratio, 3.2; 95% CI, 0.9-11.6; P =.06) trended to increased death/MI rates, with weaker trends for elevated levels of hsCRP (>7.1 mg/L), IL6 (>10.7 pg/mL), and ST depression. Other markers, other electrocardiogram changes, or classic risk factors were not predictive of death/MI. With a multivariate analysis, d-dimer and sP-selectin were found to be of independent significance for death/MI after adjustment for inflammatory, hemostatic, and electrocardiogram markers and d-dimer after adjustment for classic risk factors. CONCLUSION: Normal cTnI levels after acute chest pain does not confer absence of future risk. Concurrent assessment of d-dimer and inflammatory markers may improve risk stratification.

Analysis of Variance↗

PubMed2000

The Preterm Prediction Study: sequential cervical length and fetal fibronectin testing for the prediction of spontaneous preterm birth. National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network.

OBJECTIVES: This study was undertaken to further elucidate the pathogenesis of preterm birth by means of traditional risk factors and new markers for preterm birth derived from the Preterm Prediction Study. STUDY DESIGN: A total of 3076 women (2929 with singleton gestations and 147 with twin pregnancies) were categorized according to the presence of risk factors including black race, low body mass index, the presence of bacterial vaginosis, and previous preterm birth. At 24 and 28 weeks' gestation cervical length was measured and categorized as short (</=25 mm) or normal (>25 mm). Vaginal and cervical fetal fibronectin concentrations were measured at 24, 26, 28, and 30 weeks' gestation and results were categorized as positive (>/=50 ng/mL) or negative (<50 ng/mL). RESULTS: At 24 to 26 weeks' gestation women with each of the risk factors were more likely to have positive fibronectin test results or to have a short cervix. Among women with negative fetal fibronectin results at 24 to 26 weeks' gestation those with a short cervix were more likely to have positive fetal fibronectin results at 28 to 30 weeks' gestation, and among those with normal cervical length those women who had positive fetal fibronectin results were more likely to have a short cervix at later evaluation. Most women who had positive fetal fibronectin results at 24 to 26 weeks' gestation had negative results at 28 to 30 weeks' gestation, whereas most but not all women who had a short cervix at 24 to 26 weeks' gestation still had a short cervix at 28 to 30 weeks' gestation. In each period women with both a positive fetal fibronectin result and a short cervix were at substantially increased risk of spontaneous preterm birth; women with either marker alone had intermediate and approximately equal risks of spontaneous preterm birth, and women without either marker had a low risk of spontaneous preterm birth. CONCLUSION: Regardless of other risk factors, a short cervix predicts a subsequent positive fetal fibronectin result, and a positive fetal fibronectin result predicts subsequent cervical shortening. These data do not support a single sequence of events leading to spontaneous preterm birth.

Biomarkers↗

PubMed2001

The analysis of sensitivity, specificity, positive predictive value and negative predictive value of cold provocation thermography in the objective diagnosis of the hand-arm vibration syndrome.

The diagnosis of digital artery vasospasm in the hand-arm vibration syndrome (HAVS) is clinically based, and the need for an accurate objective test to support the diagnosis has been highlighted. This study aims to analyse the potential of cold provocation thermography (CPT) to fulfill this role. CPT was performed on two groups of subjects: 10 controls and 21 patients with Raynaud's phenomenon (RP) secondary to HAVS. After taking a pre-cooling image, patients donned latex gloves and immersed their hands in water at a temperature of 5 degrees C for 1 min. The patients removed their hands from the water and discarded the gloves, and further images were taken every 30 s for 10 min. On each image, the temperatures of the tip and base were analysed for each digit. The sensitivity, specificity, positive and negative predictive values for fingertip temperatures only, fingertip and fingerbase temperatures combined, and fingertip temperature, fingerbase temperature and temperature gradient combined were determined. Patients with RP secondary to HAVS demonstrated significantly lower finger tip and base temperatures and lower digital temperature gradients at all time intervals when compared with controls (P < 0.01, Student's t-test). CPT has good sensitivity, specificity, positive predictive value and negative predictive value; it strongly supports the clinical diagnosis of digital vasospasm.

Adult↗

PubMed2006

Predictability analysis for an automated seizure prediction algorithm.

Epileptic seizures of mesial temporal origin are preceded by changes in signal properties detectable in the intracranial EEG. A series of computer algorithms designed to detect the changes in spatiotemporal dynamics of the EEG signals and to warn of impending seizures have been developed. In this study, we evaluated the performance of a novel adaptive threshold seizure warning algorithm (ATSWA), which detects the convergence in Short-Term Maximum Lyapunov Exponent (STLmax) values among critical intracranial EEG electrode sites, as a function of different seizure warning horizons (SWHs). The ATSWA algorithm was compared to two statistical based naïve prediction algorithms (periodic and random) that do not employ EEG information. For comparison purposes, three performance indices "area above ROC curve" (AAC), "predictability power" (PP) and "fraction of time under false warnings" (FTF) were defined and the effect of SWHs on these indices was evaluated. The results demonstrate that this EEG based seizure warning method performed significantly better (P < 0.05) than both naïve prediction schemes. Our results also show that the performance indexes are dependent on the length of the SWH. These results suggest that the EEG based analysis has the potential to be a useful tool for seizure warning.

Adult↗

PubMed2003

Recognition of mycobacterial epitopes by T cells across mammalian species and use of a program that predicts human HLA-DR binding peptides to predict bovine epitopes.

Bioinformatics tools have the potential to accelerate research into the design of vaccines and diagnostic tests by exploiting genome sequences. The aim of this study was to assess whether in silico analysis could be combined with in vitro screening methods to rapidly identify peptides that are immunogenic during Mycobacterium bovis infection of cattle. In the first instance the M. bovis-derived protein ESAT-6 was used as a model antigen to describe peptides containing T-cell epitopes that were frequently recognized across mammalian species, including natural hosts for tuberculosis (humans and cattle) and small-animal models of tuberculosis (mice and guinea pigs). Having demonstrated that some peptides could be recognized by T cells from a number of M. bovis-infected hosts, we tested whether a virtual-matrix-based human prediction program (ProPred) could identify peptides that were recognized by T cells from M. bovis-infected cattle. In this study, 73% of the experimentally defined peptides from 10 M. bovis antigens that were recognized by bovine T cells contained motifs predicted by ProPred. Finally, in validating this observation, we showed that three of five peptides from the mycobacterial antigen Rv3019c that were predicted to contain HLA-DR-restricted epitopes were recognized by T cells from M. bovis-infected cattle. The results obtained in this study support the approach of using bioinformatics to increase the efficiency of epitope screening and selection.

Animals↗

PubMed1996

Adverse psychological events occurring in the first year after predictive testing for Huntington's disease. The Canadian Collaborative Study Predictive Testing.

A total of 135 participants in the Canadian predictive testing programme for HD were followed for at least one year in one of four study groups: increased risk (n = 37), decreased risk ( n = 58), uninformative (n = 17), or not tested (n = 23). Clinical criteria for an adverse event were a suicide attempt or formulation of a suicide attempt plan, psychiatric hospitalisation, depression lasting longer than two months, a marked increase in substance abuse, and the breakdown of important relationships. Quantitative criteria, as measured by changes on the General Severity Index of the Symptom Checklist 90-R and the Beck Depression Inventory, were also used to identify people who had adverse events. Twenty of the 135 participants (14.8%) had an adverse event. There were no significant differences between those with or without an adverse event with respect to age, sex, marital status, education, psychiatric history, general psychiatric distress, or social supports at baseline. However, evidence for depression was associated with an increased frequency of adverse events (p < 0.04). The adverse events were similar and seen with equivalent frequency in those receiving an increased risk or decreased risk and persons at risk who did not receive a modification of risk. However, a significant difference was found in the timing of adverse events for the increased and decreased risk groups (p < 0.0002). In the increased risk group all of the adverse events occurred within 10 days after results whereas, in the decreased risk group, all of the adverse events occurred six months or later after reviewing test results. These results suggest that people entering into predictive testing with some evidence of clinical depression warrant special vigilance and also suggest that counselling and support should be available for all participants in predictive testing irrespective of the direction of test results.

Adolescent↗

PubMed2004

Early predicted time to normalization of tumor markers predicts outcome in poor-prognosis nonseminomatous germ cell tumors.

PURPOSE: The prognostic relevance of the rate of decline of serum alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) during the first 3 weeks of chemotherapy for nonseminomatous germ cell tumors (NSGCT) was studied in the context of the International Germ Cell Cancer Collaborative Group (IGCCCG) classification. PATIENTS AND METHODS: Data from 653 patients prospectively recruited in clinical trials were studied. Tumor markers were obtained before chemotherapy and 3 weeks later. Decline rates were calculated using a logarithmic formula and expressed as a predicted time to normalization (TTN). A favorable TTN was defined when both AFP and HCG had a favorable decline rate, including cases with normal values. RESULTS: The median follow-up was 50 months (range, 2 to 151 months). Tumor decline rate expressed as a predicted TTN was associated with both progression-free survival (PFS; P <.0001) and overall survival (OS; P <.0001). The 4-year PFS rates were 64% and 38% in patients from the poor-prognosis group who had a favorable and an unfavorable TTN, respectively. The 4-year OS rates were 83% and 58%, respectively. This effect was independent from the initial tumor marker values, the primary tumor site, and the presence of nonpulmonary visceral metastases: tumor marker decline rate remained a strong predictor for both PFS (hazard ratio = 2.5; P =.01) and OS (hazard ratio = 4.6; P =.002) in patients from the IGCCCG poor-prognosis group in multivariate analysis. CONCLUSION: Early predicted time to tumor marker normalization is an independent prognostic factor in patients with poor-prognosis NSGCT and may be a useful tool in the therapeutic management of these patients.

Biomarkers, Tumor↗

PubMed2005

In silico predictive toxicology: the state-of-the-art and strategies to predict human health effects.

In silico predictive toxicology techniques are a fast and cost-efficient alternative or supplement to bioassays for the identification of toxic effects at an early stage of drug development. This review provides a conceptual description of the most important in silico prediction techniques and presents exemplary strategies for the prediction of human health effects. Special emphasis will be given to validation issues and the performance of models for human health-related effects.

Animals↗

PubMed1998

Factors predictive of survival after first relapse or progression in advanced epithelial ovarian carcinoma: a prediction tree analysis-derived model with test and validation groups.

OBJECTIVE: To identify factors predictive of overall survival after first relapse or primary progression in patients with advanced epithelial ovarian cancer. METHODS: "Tree-structured prediction of survival for censored survival data" was used to identify the independent prognostic factors in the test group (n = 352) who were the patients from the previously reported Canadian OV.8 trial. A prognostic model was developed using these factors and subjected to validation in the Canadian OV.4 trial cohort (n = 282). RESULTS: Based upon three factors, time from diagnosis to first recurrence or progression, tumor grade at diagnosis, and ECOG performance status at original diagnosis, three groups of patients were identified. These were labeled as good, intermediate, and poor prognosis with median survivals post relapse of 18 (12), 6 (5), and 1 (2) months, respectively. The figure in parentheses is the survival in the validation cohort. CONCLUSIONS: These prognostic groupings enable us to recommend second-line treatment more logically. The patients in the poor prognosis group have such a limited survival that cancer shrinking therapy should not routinely be offered. In addition the use of the individual predictive factors as stratification factors will help to avoid erroneous conclusions about treatment efficacy.

Adult↗

PubMed1993

Predicting survival from in-hospital CPR: meta-analysis and validation of a prediction model.

OBJECTIVE: To better clarify patient factors that predict survival from in-hospital cardiopulmonary resuscitation (CPR), using two methods: 1) meta-analysis and 2) validation of a prediction model, the pre-arrest morbidity (PAM) index. DESIGN: Meta-analysis of previously published studies by standard techniques. Retrospective chart review of validation sample. SETTING: University-affiliated teaching hospital. PATIENTS/PARTICIPANTS: Meta-analytic sample of 21 previous studies from 1965-1989. The validation sample consisted of all patients surviving resuscitation from the authors' hospital during the period September 1986 to January 1991. A matched sample of patients who did not survive from the same time period was used as the comparison group. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The strongest negative predictors of survival, by meta-analysis, were renal failure (r = 0.088, p < 0.0002), cancer (r = 0.08, p < 0.0002), and age more than 60 years (r = 0.063, p < 0.006). Sepsis (r = 0.046, p < 0.02), recent cerebrovascular accident (CVA) (r = 0.038, p < 0.04), and congestive heart failure (CHF) class III/IV (r = 0.036, p < 0.05) were weaker negative predictors. Presence of acute myocardial infarction (AMI) was a significant positive predictor of survival (r = 0.15, p < 0.0001). The PAM score was highly predictive of survival in a logistic regression model (p < 0.0003, R2 = 9.6%). No patient who survived to discharge had a PAM score higher than 8. CONCLUSION: Meta-analysis reveals that the most significant negative predictors of survival from CPR are renal failure, cancer, and age more than 60 years, while AMI is a significant positive predictor. The PAM index is a useful method of stratifying probability of survival from CPR, especially for those patients with high PAM scores, who have essentially no chance of survival.

Age Factors↗

PubMed1991

An extension of secondary structure prediction towards the prediction of tertiary structure.

Secondary structure prediction parameters and optimised decision constants for use with the method of Garnier et al. [(1978) J. Mol. Biol. 120, 97-120] have been derived for two new and distinct substates of beta-structure. These we term internal and external on the basis of their hydrogen bonding patterns. The profiles of the amino acids for several of the parameters are considerably different in the two substates. Predictions using the new parameters attempt to distinguish the strands at the core of the beta-sheet from those at its edges and so restrict the possible topologies in tertiary structure prediction. The potential application of these parameters is illustrated for the class of beta/alpha proteins.

Adenylate Kinase↗

PubMed2004

The incremental prognostic value of percentage of heart rate reserve achieved over myocardial perfusion single-photon emission computed tomography in the prediction of cardiac death and all-cause mortality: superiority over 85% of maximal age-predicted heart rate.

OBJECTIVES: We sought to determine whether chronotropic incompetence (CI) adds incremental value in predicting cardiac death (CD) and all-cause mortality and to determine which marker of CI is superior. BACKGROUND: Chronotropic incompetence, defined by either a low percent heart rate (HR) reserve achieved or failure to achieve 85% maximal age-predicted heart rate (MA-PHR), is a predictor of mortality. These variables have not been examined together in a comprehensive myocardial perfusion single-photon emission computed tomographic (SPECT), or MPS, model. METHODS: A total of 10,021 patients who underwent exercise MPS, evaluated by a summed stress score (SSS), were followed up for 719 +/- 252 days. Percent HR reserve = (peak HR - rest HR)/(220 - age - rest HR) x 100, with <80% considered abnormal. RESULTS: A total of 2,956 patients (29.5%) had low %HR reserve; 1,331 (13.3%) achieved <85% MA-PHR; and 1,296 (13.0%) had both. There were 234 deaths (93 CDs). On multivariate analysis, the SSS, %HR reserve, and inability to achieve 85% MA-PHR were predictors of all-cause mortality and CD (all p < 0.01). Myocardial perfusion SPECT was the most powerful predictor of CD (chi-square = 50). When the %HR reserve and ability to achieve 85% MA-PHR were considered, only the former remained a predictor of CD (p = 0.006 vs. p = 0.59). CONCLUSIONS: In a comprehensive MPS model, CI was an important predictor of CD and all-cause mortality. Percent HR reserve was superior to the ability to achieve 85% MA-PHR in predicting CD; MPS was superior to both. Combined with previous studies, the findings suggest that %HR reserve should become the standard for assessing the adequacy of HR response during exercise testing, and that it should be routinely incorporated in risk stratification algorithms.

Age Factors↗

PubMed2005

Non-conscious prediction and a role for consciousness in correcting prediction errors.

As a result of the evolutionary pressure for survival, the brain relies on a number of non-conscious predictive neural mechanisms which allow for rapid, efficient behavioral responses to the environment. These predictive mechanisms enable the brain to recognize objects by sampling just a few sensory inputs, to anticipate what events are likely to occur and to prepare a response before events actually occur. Consciousness appears to play a role in the detection and correction of prediction errors. The author, a psychotherapist and psychoanalyst, proposes that this monitoring or oversight function of consciousness can be used to understand how conscious awareness facilitates change in the psychotherapeutic treatment of patients who repeat maladaptive patterns of behavior.

Adaptation, Psychological↗

PubMed2002

Motif prediction in ribosomal RNAs Lessons and prospects for automated motif prediction in homologous RNA molecules.

The traditional way to infer RNA secondary structure involves an iterative process of alignment and evaluation of covariation statistics between all positions possibly involved in basepairing. Watson-Crick basepairs typically show covariations that score well when examples of two or more possible basepairs occur. This is not necessarily the case for non-Watson-Crick basepairing geometries. For example, for sheared (trans Hoogsteen/Sugar edge) pairs, one base is highly conserved (always A or mostly A with some C or U), while the other can vary (G or A and sometimes C and U as well). RNA motifs consist of ordered, stacked arrays of non-Watson-Crick basepairs that in the secondary structure representation form hairpin or internal loops, multi-stem junctions, and even pseudoknots. Although RNA motifs occur recurrently and contribute in a modular fashion to RNA architecture, it is usually not apparent which bases interact and whether it is by edge-to-edge H-bonding or solely by stacking interactions. Using a modular sequence-analysis approach, recurrent motifs related to the sarcin-ricin loop of 23S RNA and to loop E from 5S RNA were predicted in universally conserved regions of the large ribosomal RNAs (16S- and 23S-like) before the publication of high-resolution, atomic-level structures of representative examples of 16S and 23S rRNA molecules in their native contexts. This provides the opportunity to evaluate the predictive power of motif-level sequence analysis, with the goal of automating the process for predicting RNA motifs in genomic sequences. The process of inferring structure from sequence by constructing accurate alignments is a circular one. The crucial link that allows a productive iteration of motif modeling and realignment is the comparison of the sequence variations for each putative pair with the corresponding isostericity matrix to determine which basepairs are consistent both with the sequence and the geometrical data.

Base Pairing↗