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PubMed1997

A prospective study of Waddell signs in patients with chronic low back pain. When they may not be predictive.

STUDY DESIGN: Analysis of the treatment-outcome predictive power of Waddell signs by evaluating them before and after functional restoration, with assessment of 1-year socioeconomic outcomes. OBJECTIVE: To evaluate the presence of Waddell nonorganic signs in a group of patients with chronic low back pain presenting for functional restoration, and to determine whether they were predictive of treatment success of failure. SUMMARY OF BACKGROUND DATA: Waddell has described "nonorganic" physical signs in patients with chronic low back pain indicative of somatization. Other researchers have correlated high Waddell scores with psychosocial barriers that required additional consultation, and have suggested that diminution of a Waddell score during physical rehabilitation is predictive of subsequent therapeutic success. METHODS: Total positive Waddell signs score and individual sign scores were assessed at initial presentation for functional restoration treatment and at discharge in a group of 50 patients with chronic low back pain (average length of disability = 17.9 months; average age = 38.5 years). Patients were then tracked and assessed with a 1-year follow-up structured interview to evaluate outcome variables such as return to work, work retention, re-injury rate, health utilization, and subsequent surgery. RESULTS: Statistical analyses of these data revealed no significant associations between Waddell total positive score or changes in score and therapeutic success as measured by any of the behavioral outcomes such as return to work. Also, no predictive value was found for the individual positive signs of their changes and therapeutic success. CONCLUSIONS: Although positive Waddell signs have been found to be predictive in patients with short-term chronic low back pain, the current results suggest that, in patients who have longer duration of pain and who undergo a comprehensive functional restoration program, these signs are not significantly prognostic. Because functional restoration is an interdiscipilinary approach that effectively manages somatization complaints in a consistent manner by all treatment personnel, such complaints do not create any major barriers to recovery. Therefore, although Waddell signs may be predictive of treatment outcome in less intensive rehabilitation programs, they do not provide any predictive power in a comprehensive functional restoration program, which has a basic goal of managing barriers to recovery in a clinically efficacious manner.

Adult↗
PubMed2002

Validation of a simplified clinical index to predict evolving patterns in Crohn's disease.

BACKGROUND: Prior to this study we obtained a simple mathematical index that uses clinical variables to predict the evolution of Crohn's disease to either a stricturing or a penetrating type. This model was based on the following variables: duration of disease before diagnosis (DD), onset of symptoms (OS), anal disease (AD) and abdominal mass (AM). The aim of our study was to validate this model in an independent cohort of patients and to investigate the relationship between some of the variables and the actual pattern of Crohn's disease in the patients. MATERIAL AND METHODS: We prospectively evaluated 128 patients with Crohn's disease at the moment of diagnosis. We predicted the evolution of their disease using the mathematical model Z = -9.49 + 2.2643 (AD) - 0.0066 (DD) + 2.5282 (AM) + 1.3433 (OS). The cut-off value (reveiver operating characteristics curve) obtained in the training set of patients was P = 0.45. A value higher than this cut off discriminated patients who developed a stricturing pattern. The actual behaviour of the patients' Crohn's disease was observed after a median of 19 months from diagnosis. Of the 128 patients, 80 were classified into one of the two known patterns. Thirty-nine patients (48.8%) developed a stricturing pattern while 41 (51.2%) had a penetrating form of Crohn's disease. RESULTS: The sensitivity of the model for predicting a stricturing type was 100% and the specificity was 31.7%. A P value of < 0.45 proved to be highly reliable in predicting the evolution to a penetrating pattern (positive predictive value was 100% and negative predictive value was 58%). No statistical differences were found between stricturing-type or penetrating-type groups in terms of anal disease, abdominal mass, duration of disease or onset of symptoms. Compared to patients with the penetrating form, initial ileal location was significantly more frequent than colonic location in patients with the stricturing type of Crohn's disease. CONCLUSIONS: We have validated a simple mathematical model that is able to predict the behaviour of Crohn's disease in patients based on clinical variables collected at their initial evaluation. This model can be considered a useful tool for patient management. The anatomical location of the disease is related to the evolutive pattern.

Adolescent↗
PubMed2001

Predictive validity of the Strain Index in turkey processing.

The Strain Index is a job analysis method for determining if workers are exposed to increased risk of developing distal upper extremity disorders. Its predictive and external validity was initially demonstrated in a pork processing plant. The purpose of this study was to evaluate the predictive validity of the Strain Index in one turkey processing plant. While blinded to health outcomes, investigators analyzed the right and left sides of workers in 28 jobs using the Strain Index and classified them as "hazardous" or "safe" based on the Strain Index score. Subsequently, OSHA 200 logs were used to ascertain the occurrence of distal upper extremity disorders retrospectively. If at least one such disorder had occurred on the right or left side during the previous 3 years, that side was classified as "positive." If no such disorder was reported during the previous 3 years, that side was classified as "negative." When comparing sides, symmetry between morbidity and hazard classification was required. When comparing jobs, such symmetry was not required. Evidence of association between the hazard classifications and the morbidity classifications for the 56 sides and the 28 jobs was evaluated using 2 x 2 contingency tables. For the sides, the association between hazard classification and morbidity classification was statistically significant, with an odds ratio of 22.0. The sensitivity, specificity, positive predictive value, and negative predictive value were 0.86, 0.79, 0.92, and 0.65, respectively. Similar results were noted for the jobs--the odds ratio was 50.0, and the sensitivity, specificity, positive predictive value, and negative predictive value were 0.91, 0.83, 0.95, and 0.71. These results provide additional evidence of the external validity and predictive validity of the Strain Index.

Animals↗
PubMed2001

Prediction formulae for sleep-disordered breathing.

Prediction formulae for sleep-disordered breathing can be useful for excluding a diagnosis, establishing an a priori probability of having a positive test, and for prioritizing patient testing. In general, prediction models have high sensitivity but low specificity. In a study analyzing the performance of four previously described prediction models, sensitivities ranged from 76% to 96%, specificities ranged from 13% to 54%, while positive predictive values ranged between 69% and 77%. The models were useful in identifying patients with a respiratory disturbance index of > or = 20 so that these patients could undergo alternative diagnostic testing strategies. The Berlin Questionnaire was tested in primary care settings and was able to identify high-risk patients fairly accurately. A regression neural network performed well with a sensitivity of 99%, a specificity of 80%, a positive predictive value of 88%, and a negative predictive value of 98%. In obese snorers, a regression model utilizing daytime arterial O2 saturation and specific respiratory conductance was effective for excluding obstructive sleep apnea (OSA). In congestive heart failure patients, risk factors for central sleep apnea include male gender, atrial fibrillation, age >60 years, and wake time PaCO2 <38 mm Hg. In children, risk factors for sleep apnea include obesity, African-American race, sinus problems, and persistent wheezing. There are also racial anthropomorphic differences in OSA patients, with whites having a tendency towards brachycephaly facial types (reduced anterior-posterior cranial dimension) and African-Americans having a tendency toward leptoproscopic facial types (longer facial height and decreased facial width). Further refinement of prediction formulae will improve diagnostic accuracy.

Diagnosis, Differential↗
PubMed2003

Prediction of residual time to AIDS and death based on markers and cofactors.

A model was constructed that estimates the probability of an HIV-infected individual developing AIDS or dying within a certain time span if left untreated, based on the most recent CD4 lymphocyte count, HIV-1 RNA load, and HIV-1 phenotype, together with age, time since seroconversion, and two genetic cofactors. The model helps clinicians in deciding when to start highly active antiretroviral treatment (HAART). Data from the Amsterdam Cohort Study among homosexual men restricted to individuals with an estimated date of seroconversion (N = 280) were used. Individual predictions based on several combinations of marker and cofactor values were obtained, and their accuracy was measured using two indices of predictive value. CD4 lymphocyte count and HIV RNA load have the highest predictive value and act independently. The predictive value of the HIV phenotype is only slightly lower and greatly enhances predictions at high CD4 counts. The CCR5-Delta32 and CCR2-64I alleles have no additional predictive value. Some predictive value is lost by not knowing time since seroconversion, and some effect of calendar period is present. In summary, for prognosis, the markers CD4 count, HIV-1 RNA load, and HIV-1 phenotype (at a high CD4 count) are equally important, and the genetic cofactors considered are of no use.

Adult↗
PubMed2006

Prediction of persistence or recurrence after conization for cervical intraepithelial neoplasia III.

OBJECTIVE: To estimate the predictive factors for persistent/recurrent disease before and after conization for cervical intraepithelial neoplasia III. METHODS: Patients who received conization due to histologic diagnosis of cervical intraepithelial neoplasia III from 1998 to 2000 and who had at least one cytologic/histologic follow-up within one year of conization (n = 449) were enrolled in our study. All available demographic and pathologic parameters were analyzed. RESULTS: We performed multivariable logistic regression analysis to identify predictive factors for cervical intraepithelial neoplasia III persistence/recurrence. Age (greater than 50 years) was the only preoperative predictor and had an odds ratio equaling 3.070 (95% confidence interval [CI] 1.421-6.630, P = .004). Post-cone endocervical curettage was found to be the most statistically significant factor for predicting persistent disease (odds ratio 7.940, 95% CI 3.428-18.390, P < .001). Positive endocervical curettage was associated with 65.5% (36/55) of persistent disease, whereas negative endocervical curettage was associated with only 7.6% (26/342). Positive endocervical resection margins and multiple-quadrant disease also had predictive values with odds ratios equaling 2.972 (95% CI 1.401-6.281, P = .004) and 2.180 (95% CI 1.014-4.689, P = .046), respectively. The positive predictive values for age (> 50 years), positive endocervical curettage, positive endocervical resection margin, and multiple quadrant disease were 31.7%, 65.5%, 40.0%, and 21.9%, respectively. CONCLUSION: We found that age is the only preoperative predictive factor. Pathologic parameters, including endocervical curettage, endocervical resection margins, and multiple-quadrant disease are the only postoperative predictive factors for cervical intraepithelial neoplasia persistence or recurrence found in our study. These factors should be considered in patient management before and after therapeutic conization for cervical intraepithelial neoplasia III. LEVEL OF EVIDENCE: II-3.

Adult↗
PubMed2005

Predicting proximal femoral strength using structural engineering models.

Hip fracture related to osteoporosis and metastatic disease is a major cause of morbidity and mortality. An accurate and precise method of predicting proximal femoral strength and fracture location would be useful for research and clinical studies of hip fracture. The goals of this study were to develop a structural modeling technique that accurately predicts proximal femoral strength; to evaluate the accuracy and precision of this predicted strength on an independent data set; and to evaluate the ability of this technique to predict fracture location. Fresh human cadaveric proximal femora with and without metastatic lesions were studied using computed tomography scan-based three-dimensional structural models and mechanical testing to failure under single-limb stance-type loading. The models understated proximal femoral strength by an average of 444 N, and the precision of the predicted strength was +/- 1900 N. Therefore, the ability to predict hip strength in an individual subject is limited primarily by the level of precision, rather than accuracy. This level of precision is likely to be sufficient for many studies of hip strength. Finally, these models predict fractures involving the subcapital and cervical regions, consistent with most fractures produced experimentally under single-limb stance-type loading.

Aged↗
PubMed2004

External validation and comparison of recently described prediction rules for suspected pulmonary embolism.

PURPOSE OF REVIEW: The assessment of pretest probability, allowing the categorization of patients clinically suspected of having pulmonary embolism in low, intermediate, and high clinical probability, is an essential step in contemporary diagnostic strategies because it permits limiting the number of additional diagnostic tests, especially invasive tests. Clinical probability can be evaluated implicitly or by prediction rules. Two prediction rules for pulmonary embolism have been described: the Canadian prediction rule (the Wells score) and the Geneva prediction rule. Their original descriptions were published in 2000 and 2001, respectively. These prediction rules need to be externally validated, and, ideally, outcome studies should demonstrate that patients may be safely treated on the basis of the assessment of the clinical probability they provide. Therefore, the purpose of this review is to discuss the external validation of these rules, because this particular point has been only recently achieved. RECENT FINDINGS: Application of both rules in an external setting and in a prospective study have confirmed their validity. A recent study suggests that the best evaluation is probably based on a prediction rule associated with possible clinical override. SUMMARY: Studies comparing an empiric assessment with explicit assessment, such as the Wells simplified score or the Geneva score, have shown that the three tools show similar accuracy. External validation and use of both rules in prospective management studies have only recently been performed and have confirmed their validity. Some reports suggest that empiric assessment may be influenced by level of training. Objective prediction rules seems to be less influenced by experience and should be preferred by more junior doctors. The tool used for clinical probability assessment is probably less important than the principle of a careful clinical probability assessment in each patient with suspected pulmonary embolism.

Diagnostic Techniques, Respiratory System↗
PubMed2003

Prediction of mortality in pediatric trauma patients: new injury severity score outperforms injury severity score in the severely injured.

BACKGROUND: The Injury Severity Score (ISS) is a widely accepted method of measuring severity of traumatic injury. A modification has been proposed--the New Injury Severity Score (NISS). This has been shown to predict mortality better in adult trauma patients, but it had no predictive benefit in pediatric patients. The aim of this study was to determine whether the NISS outperforms the ISS in a large pediatric trauma population. METHODS: Admissions in the National Pediatric Trauma Registry between April 1996 and September 1999 were included. The ISS and NISS were calculated for each patient. The study endpoints were mortality at hospital discharge, functional outcome in three domains (expression, locomotion, and feeding), and discharge disposition for the survivors. Predictive ability of each score was assessed by area under the receiver operating characteristic curve. RESULTS: The NISS and ISS performed equally well at predicting mortality in patients with lower injury severity (ISS < 25), but the NISS was significantly better at predicting mortality in the more severely injured patients. Both scores performed equally well at predicting expression and feeding ability. The NISS was superior to the ISS in predicting locomotion ability at discharge. Thirty-seven percent of patients had an NISS that was higher than their ISS. These patients had a significantly higher mortality and suffered worse functional outcomes. CONCLUSION: The NISS performs as well as the ISS in pediatric patients with lower injury severity and outperforms the ISS in those with higher injury severity.

Activities of Daily Living↗
PubMed2006

Predicting hospital mortality among injured children using a national trauma database.

PURPOSE: The purpose of this study was to develop a model that accurately predicts mortality among injured children based on components of the initial patient evaluation and that is generalizable to diverse acute care settings. Important predictive variables obtained in an emergency setting are frequently missing in even large national databases, limiting their effectiveness for developing predictions. In this study, a model predicting pediatric trauma mortality was developed using a national database and methods to handle missing data that may avoid biases that can occur restricting analyses to complete cases. METHODS: Records of pediatric patients included in the National Pediatric Trauma Registry (NPTR) between 1996 and 1999 were used as a training set in a logistic regression model to predict hospital mortality using vital signs, Glasgow Coma Scale (GCS) score, and intubation status. Multiple imputation was applied to handle missing data. The model was tested using independent data from the NPTR and National Trauma Data Bank (NTDB). RESULTS: Complete case analysis identified only GCS-eye and intubation status as predictors of mortality. A model based on complete case analysis had good discrimination (c-index = 0.784) and excellent calibration (Hosmer-Lemeshow c-statistic, 6.8) (p > 0.05). Using multiple imputation, three additional predictors of mortality (systolic blood pressure, pulse, and GCS-motor) were identified and improved model performance was observed. The model developed using multiple imputation had excellent discrimination (c-index, 0.947-0.973) in both test datasets. Calibration was better in the NPTR testing set than in the NTDB (Hosmer-Lemeshow c-statistic, 9.2 for NPTR [p > 0.05] and 258.2 for NTDB [p < 0.05]). At a probability cutoff that minimized misclassification in the training set, the false-negative and false-negative rates of the model were better than those obtained with either the Revised Trauma Score (RTS) or Pediatric Trauma Score using data from the NPTR testing set. Although the false-positive rates were lower with the RTS using data from the NTDB, the false-negative rates of the proposed model and the RTS were similar in this test dataset. CONCLUSIONS: Using multiple imputation to handle missing data, a model predicting pediatric trauma mortality was developed that compared favorably with existing trauma scores. Application of these methods may produce predictive trauma models that are more statistically reliable and applicable in clinical practice.

Child↗
PubMed2004

Accurate identification of novel human genes through simultaneous gene prediction in human, mouse, and rat.

We describe a new method for simultaneously identifying novel homologous genes with identical structure in the human, mouse, and rat genomes by combining pairwise predictions made with the SLAM gene-finding program. Using this method, we found 3698 gene triples in the human, mouse, and rat genomes which are predicted with exactly the same gene structure. We show, both computationally and experimentally, that the introns of these triples are predicted accurately as compared with the introns of other ab initio gene prediction sets. Computationally, we compared the introns of these gene triples, as well as those from other ab initio gene finders, with known intron annotations. We show that a unique property of SLAM, namely that it predicts gene structures simultaneously in two organisms, is key to producing sets of predictions that are highly accurate in intron structure when combined with other programs. Experimentally, we performed reverse transcription-polymerase chain reaction (RT-PCR) in both the human and rat to test the exon pairs flanking introns from a subset of the gene triples for which the human gene had not been previously identified. By performing RT-PCR on orthologous introns in both the human and rat genomes, we additionally explore the validity of using RT-PCR as a method for confirming gene predictions.

Animals↗
PubMed2004

Gene prediction and verification in a compact genome with numerous small introns.

The genomes of clusters of related eukaryotes are now being sequenced at an increasing rate, creating a need for accurate, low-cost annotation of exon-intron structures. In this paper, we demonstrate that reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing based on predicted gene structures satisfy this need, at least for single-celled eukaryotes. The TWINSCAN gene prediction algorithm was adapted for the fungal pathogen Cryptococcus neoformans by using a precise model of intron lengths in combination with ungapped alignments between the genome sequences of the two closely related Cryptococcus varieties. This approach resulted in approximately 60% of known genes being predicted exactly right at every coding base and splice site. When previously unannotated TWINSCAN predictions were tested by RT-PCR and direct sequencing, 75% of targets spanning two predicted introns were amplified and produced high-quality sequence. When targets spanning the complete predicted open reading frame were tested, 72% of them amplified and produced high-quality sequence. We conclude that sequencing a small number of expressed sequence tags (ESTs) to provide training data, running TWINSCAN on an entire genome, and then performing RT-PCR and direct sequencing on all of its predictions would be a cost-effective method for obtaining an experimentally verified genome annotation.

Algorithms↗
PubMed2000

Prediction of short cardiovascular variability signals based on conditional distribution.

A new approach measuring the predictability of a process is proposed. The predictor is defined as the median of the distribution conditioned by a sequence of L - 1 previous samples (i.e., a pattern). A function referred to as the corrected mean squared predictor error is defined to prevent the perfect adequacy to the data (i.e., the decrease to zero of the prediction error), thus avoiding to divide the whole set of data in learning and test sets. This function exhibits a minimum and this minimum is taken as a measure of predictability of the series. The use of the minimization procedure avoids to fix a priori the pattern length L. This approach permits one a reliable measure of predictability on short data sequences (around 300 samples). Moreover, this method, in connection with a surrogate data approach, is useful to detect nonlinear dynamics. The analysis indicates that, in simulated and real data, predictability and nonlinearity measures provide different information. The application of this approach to the analysis of cardiovascular variability series of the heart period (RR interval) and systolic arterial pressure (SAP) shows: 1) SAP series is more predictable than RR interval series; 2) predictability of the RR interval series is larger during tilt, during controlled respiration at 10 breaths/min (bpm) and after high-dose administration of atropine; 3) SAP series is dominated by linear correlation; 4) RR interval series exhibits nonlinear dynamics during controlled respiration at 10 bpm and after low-dose administration of atropine, while it is linear during sympathetic activation produced by tilt and after peripheral parasympathetic blockade caused by high-dose administration of atropine.

Adult↗
PubMed2004

Database analyses for the prediction of in vivo drug-drug interactions from in vitro data.

AIMS: In theory, the magnitude of an in vivo drug-drug interaction arising from the inhibition of metabolic clearance can be predicted using the ratio of inhibitor concentration ([I]) to inhibition constant (K(i)). The aim of this study was to construct a database for the prediction of drug-drug interactions from in vitro data and to evaluate the use of the various estimates for the inhibitor concentrations in the term [I]/K(i). METHODS: One hundred and ninety-three in vivo drug-drug interaction studies involving inhibition of CYP3A4, CYP2D6 or CYP2C9 were collated from the literature together with in vitro K(i) values and pharmacokinetic parameters for inhibitors, to allow calculation of average/maximum systemic plasma concentration during the dosing interval and maximum hepatic input plasma concentration (both total and unbound concentration). The observed increase in AUC (decreased clearance) was plotted against the estimated [I]/K(i) ratio for qualitative zoning of the predictions. RESULTS: The incidence of false negative predictions (AUC ratio > 2, [I]/K(i) < 1) was largest using the average unbound plasma concentration and smallest using the hepatic input total plasma concentration of inhibitor for each of the CYP enzymes. Excluding mechanism-based inhibition, the use of total hepatic input concentration resulted in essentially no false negative predictions, though several false positive predictions (AUC ratio < 2, [I]/K(i) > 1) were found. The incidence of true positive predictions (AUC ratio > 2, [I]/K(i) > 1) was also highest using the total hepatic input concentration. CONCLUSIONS: The use of the total hepatic input concentration of inhibitor together with in vitro K(i) values was the most successful method for the categorization of putative CYP inhibitors and for identifying negative drug-drug interactions. However this approach should be considered as an initial discriminating screen, as it is empirical and requires subsequent mechanistic studies to provide a comprehensive evaluation of a positive result.

Aryl Hydrocarbon Hydroxylases↗
PubMed2005

Estimation of total body water from foot-to-foot bioelectrical impedance analysis in patients with cancer cachexia - agreement between three prediction methods and deuterium oxide dilution.

INTRODUCTION: Bioelectrical impedance analysis (BIA) is a useful bedside measure to estimate total body water (TBW). The aim of this study was to determine the agreement between three equations for the prediction of TBW using BIA against the criterion method, deuterium oxide dilution, in patients with cancer cachexia. METHODS: Eighteen measurements of TBW using foot-to-foot BIA in seven outpatients with cancer cachexia (five male and two female, age 56.4 +/- 6.7 years) at an Australian hospital. Three prediction formulae were used to estimate TBW - TBW(ca-radiotherapy) developed in patients with cancer undergoing radiotherapy, TBW(ca-underweight) and TBW(ca-normal weight) developed in underweight and normal weight patients with cachexia. TBW was measured using the deuterium oxide dilution technique as the gold standard. RESULTS: Mean measured TBW was 39.5 +/- 6.0 L. There was no significant difference in measured TBW and estimates from prediction equations TBW(ca-underweight) and TBW(ca-radiotherapy). There was a significant difference in measured TBW and TBW(ca-normal weight). All prediction equations overestimated TBW in comparison with measured TBW. The smallest bias was observed with TBW(ca-underweight) (0.38 L). The limits of agreement are wide (>7.4 L) for each of the prediction equations compared with measured TBW. CONCLUSIONS: At a group level, TBW(ca-underweight) is the best predictor of measured TBW in patients with cancer cachexia. For an individual however, the limits of agreement are wide for all prediction equations and are unsuitable for use. Practitioners need to be aware of the limitations of using TBW prediction equations for individuals.

Body Composition↗
PubMed2006

Impact of follow-up time and re-measurement of the electrocardiogram and conventional cardiovascular risk factors on their predictive value for myocardial infarction.

OBJECTIVE: To explore if the predictive power of mid-life electrocardiogram (ECG) abnormalities and conventional cardiovascular risk factors for future myocardial infarction, change over a 30-year follow-up period and if repeated examination improves their predictive power. DESIGN AND SETTING: Longitudinal population-based study. PARTICIPANTS: A total of 2322 men aged 50 years, with a total follow-up period of 30 years and 1221 subjects were re-examined at age of 70 years. MAIN OUTCOME MEASURE: Risk for fatal and nonfatal myocardial infarction (n = 470) analysed at age 50 and 70 years, and separately for 1-10, 11-20 and 21-30 years after first examination. Investigations included a 12-lead ECG, blood pressure, body mass index, smoking habits, and glucose and lipid variables. RESULTS: Whilst high blood pressure and dyslipidaemia variables, such as apolipoprotein B/apolipoprotein A1 ratio, measured at age 50 showed an almost unchanged predictive power during the three decades of follow up, ECG abnormalities, insulin and BMI were only significant predictors during the two first decades of follow up. Despite increased prevalences of ECG abnormalities and obesity with age, they predicted for future myocardial infarction in midlife only whilst fasting insulin and smoking regained their predictive power when re-measured at age 70. CONCLUSION: Whilst hypertension and dyslipidaemia were consistent as risk factors, length of follow-up period and age at baseline investigations affected the predictive power of ECG abnormalities, fasting insulin, BMI and smoking. In the elderly, ECG abnormalities did not contribute to the prediction of myocardial infarction but smoking and fasting insulin may be important in the pathophysiology leading to MI especially in this age group.

Age Factors↗
PubMed2004

A prospective study of the predictive power of spiral computed tomographic angiography for defining renal vascular anatomy before live-donor nephrectomy.

OBJECTIVE: To determine the accuracy of spiral computed tomography (CT) imaging of donor venous anatomy by comparing CT angiography (CTA) and operative findings, for both laparoscopic (LDN) and open donor nephrectomy. PATIENTS AND METHODS: LDN presents unique surgical challenges, particularly with complex venous or arterial anatomy. The limitations of surgical access, poor visibility of the superior and posterior borders of the renal vein during LDN, and the variability of venous anatomy in this region, contribute to the difficulty of LDN, underlining the importance of imaging beforehand. Forty live donors (mean age 46 years, sd 11; 65% female) were assessed by CTA before donation. Scans were reported by the same radiologist. The number and diameter of 'predicted' renal arteries, veins and renal vein tributaries were documented. The donor kidney was removed by two consultant surgeons, and after back-table perfusion the same details were recorded and taken as the 'reference' findings. Tributaries of <1 mm diameter were not recorded. The right kidney was retrieved in seven patients; 25 of the 40 kidneys were retrieved by LDN and the other 15 by open surgery. RESULTS: In all, 48 actual renal arteries were identified at nephrectomy; of these, 47 were predicted by CTA. Likewise, 41 actual renal veins were found at nephrectomy, 40 of which were predicted. The overall accuracy of spiral CTA in predicting the presence or absence of renal vein tributaries was 83% for gonadal and adrenal veins, and 75% for lumbar veins. There were seven false-negative lumbar veins found at nephrectomy; in these cases the CTA films were retrospectively examined, and five of these seven veins were identified. The predicted renal vein tributary diameter correlated poorly with the measured diameter at nephrectomy. CONCLUSIONS: Assessing potential renal donors before surgery with spiral CTA provides an accurate prediction of the presence or absence of the gonadal and adrenal vein, but is less accurate for predicting lumbar veins. This is especially pertinent as the posterior lumbar tributaries have the most intra-individual variation, and are the most difficult to display and control at LDN. This highlights the need for meticulous dissection of the renal vein, particularly along its posterior wall.

Female↗
PubMed1993

A practical equation to predict resting metabolic rate in older females.

OBJECTIVE: To develop a practical and accurate age-specific equation for predicting resting metabolic rate (RMR) in older women and, thereafter, to cross-validate existing equations for predicting RMR in older females. DESIGN: Cross-sectional validation study. SETTING: General Clinical Research Center. PARTICIPANTS: A convenience sample of 75 healthy older women (age 50-81) free of significant cardiovascular or any other non-cardiac disease that may affect cardiovascular function or metabolic rate. MEASUREMENTS: All 75 volunteers were characterized for resting metabolic rate (RMR), body composition, anthropometrics, physical activity, and energy intake. RESULTS: A practical equation for predicting RMR in older women using easily measured variables was: [RMR (kcal/d) = 7.8 (weight,kg) + 4.7 (standing height, cm) -39.5 (menopausal status; 1-3) + 143.5]. These variables accounted for 59% (R2) of the variation in RMR and predicted RMR within +/- 66 kcal/d. When five previously published equations were applied to our sample of older women to predict RMR, individual predicted values deviated by -31% to 20% from the measured value. CONCLUSION: We offer a practical equation to predict RMR in healthy older women based on a measure of body weight, standing height, and menopausal status.

Academic Medical Centers↗