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PubMed2006

Subtype specific prognostic nomogram for patients with primary liposarcoma of the retroperitoneum, extremity, or trunk.

OBJECTIVE: To determine the prognostic significance of histologic subtype in a large series of patients with primary liposarcoma (LS) and to construct a LS-specific postoperative nomogram for disease-specific survival (DSS). SUMMARY BACKGROUND DATA: Nomograms, used to define and predict outcome following operative intervention, may contain variables not conventionally used in standard staging systems. A 12-year DSS postoperative nomogram for all sarcomas has already been established. METHODS: From a single-institution prospective sarcoma database, patients with primary extremity, truncal, or retroperitoneal LS treated between 1982 and 2005 were identified. Histology was reviewed by a sarcoma pathologist and divided into 5 subtypes. A nomogram predictive of 5- and 12-year DSS was developed. RESULTS: Of 801 patients with primary LS resected with curative intent, 369 (46%) presented with well-differentiated, 143 (18%) dedifferentiated, 144 (18%) myxoid, 81 (10%) round cell, and 64 (8%) pleomorphic histology. The median tumor burden was 15 cm (range, 1-139 cm). At last follow-up, 560 patients were alive with a median follow-up time of 45 months (range, 1-264 months) and 51 months for surviving patients. The 5- and 12-year DSS rates were 83% (95% confidence interval [CI], 80%-86%) and 72% (95% CI, 67%-77%), respectively. The nomogram was drawn on the basis of a Cox regression model. The independent predictors of DSS were age, presentation status, histologic variant, primary site, tumor burden, and gross margin status. The nomogram was internally validated using bootstrapping and shown to have excellent calibration. The concordance index was 0.827 compared with 0.776 for the general sarcoma postoperative nomogram for 12-year DSS. CONCLUSION: The LS-specific nomogram based on histologic subtype provides more accurate survival predictions for patients with primary LS than the previously established generic sarcoma nomogram. DSS nomograms aid in more accurate counseling of patients, identification of patients appropriate for adjuvant therapy, and stratification of patients for clinical trials and molecular analysis.

Adolescent↗

PubMedDate not supplied

Optimizing hospital use of intravenous insulin therapy: improved management of hyperglycemia and error reduction with a new nomogram.

OBJECTIVE: To assess the efficacy and safety of intravenous (IV) insulin administration with use of our institution's old protocol (pre-nomogram phase) as compared with our new insulin nomogram (post-nomogram phase), which titrates insulin dose based on the rate of change of plasma glucose values and uses multipliers to determine the new insulin infusion rate. METHODS: Hospitalized adults receiving an IV insulin infusion in our tertiary care medical center were enrolled in this study after informed consent was obtained. The study was an observational analysis conducted before and after implementation of the new insulin infusion nomogram. Measurements included episodes of hypoglycemia and incidence of the following errors in the insulin infusion process: (1) episodes of documented failure to increase insulin infusion rate despite persistent hyperglycemia and (2) number of times the IV infusion was stopped without subcutaneous administration of insulin. RESULTS: Overall, 66 patients were analyzed (38 in the pre-nomogram phase and 28 in the post-nomogram phase). The new nomogram reduced by nearly 3-fold (from 0.89 +/- 0.68 to 0.36 +/- 0.49 occurrence per patient per 24 hours; P<0.001) the mean incidence of failure to give insulin subcutaneously before discontinuation of IV insulin infusion. Moreover, the nomogram nearly eliminated the error of caregiver nonresponsiveness to persistent hyperglycemia: mean incidence 0.39 +/- 0.65 occurrence per patient per 24 hours before implementation of the new nomogram versus 0.02 +/- 0.09 afterward (P<0.002). There was no statistically significant difference in episodes of hypoglycemia between the 2 study groups. CONCLUSION: Safe IV administration of insulin through error prevention is essential. Implementation of a new IV insulin infusion nomogram, which adjusts insulin infusion using multipliers, reduces errors and improves glycemic control without increasing hypoglycemic episodes.

Adult↗

PubMed2004

Validation of the Kattan preoperative nomogram for prostate cancer recurrence using a community based cohort: results from cancer of the prostate strategic urological research endeavor (capsure).

PURPOSE: The Kattan preoperative nomogram combines preoperative prostate specific antigen (PSA), biopsy Gleason grade and clinical stage to estimate disease recurrence after radical prostatectomy. Several studies using patient data from academic centers have validated the nomogram. We assessed the performance of the Kattan nomogram using the Cancer of the Prostate Strategic Urological Research Endeavor database, a national, largely community based observational disease registry. MATERIALS AND METHODS: From the Cancer of the Prostate Strategic Urological Research Endeavor database we identified 1701 men with clinically localized prostate cancer undergoing radical prostatectomy with sufficient pretreatment information and PSA followup after surgery. Disease recurrence was defined as 2 consecutive PSA values 0.2 ng/ml or greater, or a second cancer treatment more than 6 months after prostatectomy. A concordance index was used to evaluate the performance of the nomogram compared to observed 5-year recurrence-free survival (Kaplan-Meier). Kattan nomogram scores were calculated for each patient and stratified into 6 groups for analysis. RESULTS: In our cohort of 1701 men 413 (24%) had evidence of disease recurrence. Median followup in these patients was 2.3 years. Kattan nomogram scores were 17% to 99% (mean 79%). The overall concordance index was 0.68. Varying the definition of recurrent disease and excluding patients with imputed data did not substantially alter nomogram performance (concordance index 0.65 to 0.70). The Kattan nomogram tended to overestimate 5-year freedom from recurrence in patients with scores of 65% and higher. CONCLUSIONS: We noted the reasonable performance of the Kattan nomogram for predicting cancer outcomes after radical prostatectomy using a community based population. Although concordance is lower than in previous validation studies and the nomogram overestimates recurrence-free survival in patients at lower risk, the model is fairly robust and it provides important information when counseling patients regarding treatment options in the community setting. Further refinements in pretreatment estimation of disease-free survival and ultimately overall survival are needed.

Cohort Studies↗

PubMed2002

Validation of a weight-based nomogram for the use of intravenous heparin in transient ischemic attack or stroke.

BACKGROUND AND PURPOSE: Intravenous heparin therapy is often used in patients presenting with transient ischemic attack (TIA) or stroke as either bridging therapy for anticoagulation with warfarin or primary therapy in suspected intracranial arterial dissection, crescendo TIAs, or suspected hypercoagulable states. We attempted to validate the use of a weight-based nomogram for heparin-adjusted therapy during hospital admission of patients with TIA or stroke. METHODS: A prospective, single-blinded, randomized, clinical trial was undertaken to compare the use of a specially designed, weight-based heparin nomogram against the traditional method of physician-ordered heparin therapy for patients admitted with TIA or stroke. The trial was not designed to examine the efficacy of heparin therapy but to examine the use of the nomogram for labor requirements, costs of monitoring, safety, length of heparin therapy, and user-friendliness. RESULTS: Pretreatment clinical factors were comparable between those randomized to use of the nomogram (n=101) and to usual care (n=105). Nomogram patients had a significantly lower first activated partial thromboplastin time than nonnomogram patients (60.6 +/- 16.8 versus 69.8 +/- 28.7 seconds). Patients treated by nomogram achieved a therapeutic range of anticoagulation sooner than nonnomogram patients (13.4 +/- 17.0 versus 17.9 +/- 14.1 hours). The fraction of time during which anticoagulation was therapeutic was significantly greater in patients on nomogram therapy (74 +/- 25% versus 67 +/- 26%). Nomogram patients also had significantly fewer supratherapeutic coagulation results, significantly fewer dose adjustment mistakes, significantly fewer calls to house staff regarding anticoagulation, and significantly fewer total complications than nonnomogram patients. The times required for discontinuation of heparin and discharge from hospital were not significantly different. A survey of house staff and nursing staff showed a preference for nomogram use. CONCLUSIONS: The heparin nomogram is a user-friendly method of maintaining heparin infusions and is associated with improved anticoagulation measures, fewer total complications related to heparin therapy, fewer mistakes in heparin dosage adjustment, and decreased labor on the part of house staff and nursing staff.

Aged↗

PubMed2006

Validation of a breast cancer nomogram for predicting nonsentinel lymph node metastases after a positive sentinel node biopsy.

BACKGROUND: Although completion lymph node dissection (CLND) is the standard of care for breast cancer patients with sentinel lymph node (SLN) metastases, the SLN is the only node with tumor in 40% to 60% of cases. To assist with decision-making regarding CLND, investigators at Memorial Sloan-Kettering Cancer Center devised and validated a nomogram for predicting the likelihood of non-SLN metastases. To assess the generalizable use of this nomogram, validation analysis was performed by using an external database. METHODS: Eight clinicopathologic variables for 200 consecutive breast cancer patients at the University of Texas M. D. Anderson Cancer Center with SLN metastases and CLND were entered into the nomogram. The accuracy of the nomogram to predict non-SLN metastases was assessed by the receiver operating characteristic (ROC) curve and linear regression analysis. The accuracy of the nomogram with touch-imprint cytology (TIC) as a substitute variable for frozen section was also evaluated. RESULTS: The linear correlation coefficient of the nomogram-predicted probabilities correlated with the observed incidence of non-SLN metastases for all patients (.97). The accuracy of the nomogram as measured by the area under the ROC curve was .71. When applied solely to patients who had TIC assessment of the SLN, the area under the ROC curve was .74. CONCLUSIONS: This study validated the Memorial Sloan-Kettering Cancer Center breast cancer nomogram by using an external database. TIC seems to be an acceptable substitute for frozen section as a nomogram variable. The nomogram may help predict an individual's risk of non-SLN metastases and assist in patient decision making regarding the benefit of CLND.

Algorithms↗

PubMed2005

The Vienna nomogram: validation of a novel biopsy strategy defining the optimal number of cores based on patient age and total prostate volume.

PURPOSE: We conducted a trial in patients with prostate specific antigen (PSA) levels from 2 to 10 ng/ml to validate a newly developed nomogram that defines the optimal number of biopsy cores required for prostate cancer (PCa) detection based on patient age and total prostate volume (Vienna nomogram). MATERIALS AND METHODS: A total of 502 patients underwent transrectal ultrasound guided prostate biopsy using the Vienna nomogram. These results were compared with those of a previous group of 1,051 patients who had standard octant biopsies followed by systematic repeat biopsies after 6 to 8 weeks if the initial biopsy result was negative for PCa. RESULTS: The overall PCa detection rate using the Vienna nomogram was 36.7% compared with 22% on first and 10% on repeat biopsy in the control group. The PCa detection rate using the Vienna nomogram was superior (p=0.002) to the octant biopsy technique, and comparable to a combination of first and repeat biopsy in the control group. Multivariate analysis of the Vienna nomogram showed that only PSA and the number of cores were independent predictors of PCa detection (chi-square = 49, p <0.001). Total prostate volume, transition zone volume and age were not independent predictors of PCa detection. CONCLUSIONS: The Vienna nomogram offers an easy tool to select the optimal number of prostate biopsy cores based on patient age and total prostate volume in PSA range 2 to 10 ng/ml. Cancer detection is significantly improved (66.4%) compared to the control group. The bias factor of larger prostate volume is eliminated by using the Vienna nomogram. Moreover, the Vienna nomogram is advantageous not only in terms of the improved PCa detection rate but also economically makes systematic repeat biopsies unnecessary.

Adult↗

PubMed2005

Validation of a postresection pancreatic adenocarcinoma nomogram for disease-specific survival.

PURPOSE: Nomograms are statistically based tools that provide the overall probability of a specific outcome. They have shown better individual discrimination than the current TNM staging system in numerous patient tumor models. The pancreatic nomogram combines individual clinicopathologic and operative data to predict disease-specific survival at 1, 2, and 3 years from initial resection. A single US institution database was used to test the validity of the pancreatic adenocarcinoma nomogram established at Memorial Sloan-Kettering Cancer Center. PATIENTS AND METHODS: The nomogram was created from a prospective pancreatic adenocarcinoma database that included 555 consecutive patients between October 1983 and April 2000. The nomogram was validated by an external patient cohort from a retrospective pancreatic adenocarcinoma database at Massachusetts General Hospital that included 424 consecutive patients between January 1985 and December 2003. RESULTS: Of the 424 patients, 375 had all variables documented. At last follow-up, 99 patients were alive, with a median follow-up time of 27 months (range, 2 to 151 months). The 1-, 2-, and 3-year disease-specific survival rates were 68% (95% CI, 63% to 72%), 39% (95% CI, 34% to 44%), and 27% (95% CI, 23% to 32%), respectively. The nomogram concordance index was 0.62 compared with 0.59 with the American Joint Committee on Cancer (AJCC) stage (P = .004). This suggests that the nomogram discriminates disease-specific survival better than the AJCC staging system. CONCLUSION: The pancreatic cancer nomogram provides more accurate survival predictions than the AJCC staging system when applied to an external patient cohort. The nomogram may aid in more accurately counseling patients and in better stratifying patients for clinical trials and molecular tumor analysis.

Adenocarcinoma↗

PubMed2005

Predicting nonsentinel node status after positive sentinel lymph biopsy for breast cancer: clinicians versus nomogram.

BACKGROUND: With increasing frequency, breast cancer patients and clinicians are questioning the need for completion axillary lymph node dissection (ALND) in the setting of a positive sentinel lymph node (SLN). We previously developed a nomogram to estimate the likelihood of residual disease in the axilla after a positive SLN biopsy result. In this study, we compared the predictions of clinical experts with those generated by the nomogram and evaluated the ability of the nomogram to change clinicians' behavior. METHODS: Pathologic features of the primary tumor and SLN metastases of 33 patients who underwent completion ALND were presented to 17 breast cancer specialists. Their predictions for each patient were recorded and compared with results from our nomogram. Subsequently, clinicians were presented with clinical information for eight patients and asked whether they would perform a completion ALND before and after being presented with the nomogram prediction. RESULTS: The predictive model achieved an area under the receiver operating characteristic curve of .72 when applied to the test data set of 33 patients. In comparison, the clinicians as a group were associated with an area under the receiver operating characteristic curve of .54 (P < .01 vs. nomogram). With regard to performing a completion ALND, providing nomogram results did not alter surgical planning. CONCLUSIONS: Our predictive model seemed to substantially outperform clinical experts. Despite this, clinicians were unlikely to change their surgical plan based on nomogram results. It seems that most clinicians can improve their predictive ability by using the nomogram to predict the likelihood of additional non-SLN metastases in a woman with a positive SLN biopsy result.

Adult↗

PubMed1995

Improved Anticoagulation with a Weight-Adjusted Heparin Nomogram in Patients with Acute Coronary Syndromes: A Randomized Trial.

The optimal heparin dosing schedule to achieve rapid and therapeutic anticoagulation has not been established. The objective of this study is to determine whether an intravenous heparin dosing nomogram based on body weight achieves adequate anticoagulation more rapidly than a standard-care nomogram. Sixty-four patients requiring intravenous heparin treatment for acute coronary syndromes, but who did not receive thrombolytic therapy, were randomized to a standard-care nomogram in which heparin was given as a 5000 unit IV bolus followed by 1000 U/hr, or a weight-adjusted nomogram in which heparin was given as an 80 U/kg IV bolus and 18 U/kg/hr. Activated partial thromboplastin time (APTT) values were checked at 6, 12, 18, 24, and 48 hours and adjusted either by 100-200 U/hr (standard-care nomogram) or by 2-4 U/kg/hr (weight-based nomogram). Activated partial thromboplastin times were measured using a widely generalizable laboratory method. The primary goal was to achieve and maintain the APTT between 60 and 90 seconds. The median APTT values were higher in the weight-adjusted group compared with the standard-care group at 6, 12, 18, 24, and 48 hours: 150 versus 83 (p = 0.001), 100 versus 79 (p = 0.09), 66 versus 61 (p = 0.005), 63 versus 56 (p = 0.09), and 64 versus 56 (p = 0.11). At 18 hours only 11% of patients in the weight-adjusted group had an APTT <61 compared with 26% in the standard-care nomogram (p = 0.007). No major bleeding complications were noted in either group. A weight-adjusted heparin nomogram offers improved anticoagulation in the first 24 hours after heparin initiation compared with a standard-care nomogram in patients with acute coronary artery syndromes.

Journal Article↗

PubMed1994

A nomogram approach to hemodialysis urea modeling.

Two sets of nomograms were developed for modeling hemodialysis urea kinetics. The first set is designed to arrive at an initial dialysis prescription. One nomogram estimates the mass transfer area coefficient (KoA) based on urea clearances of a dialyzer, based on urea clearances provided in the manufacturer's product literature. A second nomogram uses the dialyzer KoA value to estimate the expected in vivo urea clearance (K) based on the nominal blood flow rate. The computations include corrections for blood flow-related errors in urea clearance, blood water content, and cardiopulmonary recirculation. Mean urea clearance measured in a series of patients was 226 +/- 22 mL/min and did not differ significantly from mean clearance estimated using this nomogram (232 +/- 8 mL/min). Another pair of nomograms, based on an anthropometric formula, can be used to estimate urea distribution volume (V) from patient sex, height, and weight. The first set of nomograms is designed to estimate an initial dialysis prescription because the nomograms propose an estimated K and an estimated V. Once the target Kt/V is chosen, the appropriate initial treatment time (t) is computed algebraically. The second set of nomograms was developed to verify delivery of the dialysis prescription and to estimate the normalized protein catabolic rate (PCRn). Kt/V is estimated from the postdialysis to predialysis blood urea nitrogen ratio and the ratio of ultrafiltrate volume to postdialysis weight (UF/W). The PCRn is estimated from the predialysis blood urea nitrogen and Kt/V. In a series of 115 patients, Kt/V and PCRn determined from the nomograms correlated highly with corresponding values determined from formal urea modeling (r = 0.99).(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗

PubMed2002

Comparisons of nomograms and urologists' predictions in prostate cancer.

When applying nomograms to a clinical setting it is essential to know how their predictions compare with clinicians'. Comparisons exist outside of the prostate cancer literature. We reviewed these comparisons and conducted 2 experiments comparing predictions of clinicians with prostate cancer nomograms. By using Medline, we searched studies from January 1966 to July 1999 that compared human predictions with nomogram predictions. Next, we conducted 2 experiments: (1) 17 urologists were presented with 10 case vignettes and asked to predict the 5-year recurrence-free probabilities for each patient; (2) case presentations of 63 prostate cancer patients (including full clinical histories with complete diagnostic data and surgical findings) were made to a group of 25 clinicians who were asked to predict organ-confined disease. We found 22 published studies comparing human experts with nomograms, greater than half (13 of 22) showed the nomogram performing above the level of the human expert. Our first experiment showed urologist modification of 165 nomogram predictions led to a decrease in prediction accuracy (c-index decreased from.67 to.55, P <.05). In our second experiment, clinician predictions of organ-confined disease were comparable to the nomogram (area under the receiver operating characteristic curve [AUC] 0.78 and 0.79, respectively). A mixed-model suggests the nomogram did not augment clinician prediction accuracy (doctor excess error 1.4%, P =.75, 95% confidence interval [CI]: -10.9% to 8.2%). Our data suggest that nomograms do not seem to diminish predictive accuracy and they may be of significant benefit in certain clinical decision making settings.

Carcinoma↗

PubMed2006

Development and validation of a nomogram for predicting outcome of patients with vulvar cancer.

OBJECTIVE: To construct and validate a nomogram to predict relapse-free survival of patients treated for vulvar cancer. METHODS: Data from 244 patients treated for vulvar cancer at a single institution (Creteil, France) were used as a training set to develop and calibrate a nomogram for predicting relapse-free survival and local relapse-free survival. We used bootstrap resampling for the internal validation and we tested the nomogram on an independent validation set of patients (Torino, Italy) for the external validation. RESULTS: The nomograms were based on a Cox proportional hazards regression model. Covariates for the relapse-free survival model included age, T stage, number of metastatic nodes, bilateral lymph node involvement, omission of the lymphadenectomy, margin status, lymphovascular space invasion, and depth of invasion. The concordance indices were 0.85 and 0.83 in the training set before and after bootstrapping, respectively, and 0.83 in the validation set. The predictions of our nomogram discriminated better than did the International Federation of Gynecology and Obstetrics stage (0.83 compared with 0.78, P = .01). The calibration of our nomogram was good. In the validation set, 2-year and 5-year relapse-free survival were well predicted with less than 5% difference between the predicted and observed survivals for each quartile. A nomogram for predicting local relapse was also developed. CONCLUSION: We have developed nomograms for predicting distant and local relapse of vulvar cancer at 2 and 5 years and validated them both internally and externally. These nomograms will be freely available on the International Society for the Study of Vulvovaginal Disease Web site. LEVEL OF EVIDENCE: III.

Adult↗

PubMed2000

Utilization and effectiveness of a weight-based heparin nomogram at a large academic medical center.

OBJECTIVE: To determine the utilization rate of a weight-based heparin nomogram and to assess the performance of the nomogram outside of experimental conditions. STUDY DESIGN: Prospective cohort analysis. PATIENTS AND METHODS: A total of 747 consecutive patients treated with intravenous heparin therapy for any indication on an internal medicine service were evaluated for the utilization rate of the weight-based nomogram, the time needed to exceed heparin's therapeutic threshold (activated partial thromboplastin time [aPTT] of > 1.5 times the control value), and the time needed to achieve heparin's therapeutic range (aPTT of 1.5 to 2.4 times the control value). Physicians were encouraged to use the weight-based nomogram by using conventional continuing medical education techniques and by configuring the computerized order entry system to give physicians an equally easy and voluntary choice between choosing the weight-based nomogram or ordering heparin in the traditional fashion. RESULTS: The study program had no effect in increasing the utilization rate of the nomogram; this rate remained the same as before the program was initiated (10%). Less time was needed both to exceed the therapeutic threshold and to achieve a therapeutic range with the weight-based nomogram compared with physician-guided dosing (P < .001 and P = .021, respectively). No difference was demonstrated between the weight-based and physician-guided groups in incidence of bleeding complications or in the proportion of patients with one or more supratherapeutic aPTTs. CONCLUSIONS: The weight-based nomogram led to superior intermediate outcomes compared with physician-guided dosing. However, despite efforts intended to modify physician behavior, the utilization rate remained so low that it was ineffective. Further research into the reasons why physicians chose not to use the weight-based nomogram and further research into methods to translate efficacious therapies into effective patient care are indicated.

Academic Medical Centers↗

PubMed2003

[The urodynamic nomogram in defining the degree of obstruction in patients with benign prostatic enlargement--defining clear obstruction].

OBJECTIVE: In order to define clear urodynamic obstruction, all patients from unclassified zone of the nomograms are to be allocated in the zone of obstruction or out of obstruction combining the parameters of different nomograms. Then, to analyze difference of the physical and radiological variables between obstructed and unobstructed groups. Finally, to determine the percentage of the patients with additional urinary bladder co morbidities in clear obstruction zone. SAMPLE AND METHODOLOGY: 102 patients with proved BPE underwent complete urodynamic investigations, (uroflowmetry, cystometry and pressure/flow studies). All methodology of measurement and definitions were based on the definitions of the International Continence Society. Basic urodynamical data were manually plotted on the Abrams-Griffiths, URA, ICS and Schafer nomograms; A/G number was calculated as well. Then, patients were allocated in the region of clear obstruction from II region of Schafer nomogram by the several models (URA number of > or = 29 cmH20, according to the strength of detrusor contraction, opening detrusor pressure > or = 40 cmH2O, PdetQmax > 50 cmH2O with Qmax < 15 ml/s), comparing matching degree to the ICS nomogram. RESULTS: Combining URA > or = 29 cmH2O (group-specific urethral resistence) and II zone of the Schafer nomogram the best allocation of the patients and best fitting to the ICS nomogram was achieved (99.1% of the cases). 65 patients (63.7%) went in the clear obstruction zone and 35 patients (36.3%) in the unobstructed zone. Student test, with 2-tail level of significance showed difference in the detrusor opening pressure (p < 0.01) among groups, although there is no difference in the premicturation detrusor pressure (p > 0.05), but there is clear difference in the duration of the detrusor contraction between obstructed and unobstructed groups (DCD; p < 0.005), independently of the grade of the detrusor contraction (GDC; p > 0.05). Obstructed group has a smaller cystometric capacity (p < 0.05), although there is no difference in the volume of voided urine (p > 0.05). Noticed is increased incidence of the detrusor instability in the obstructed group (42% versus 22%, p < 0.0005). Analyze of physical variables has shown that there is a difference in the prostate volume among the groups (p < 0.05), and the patients age (p < 0.05), albeit there is no difference in the level of I-PSS, QOL scores (p > 0.05) and post void residual urine volume (p > 0.05), as well. Out of the 65 obstructed patients, only 23 patients (35.3%) have uncomplicated urodynamical obstruction, while other 42 patients (64.7%) have additional detrusor instability or hypocontractility, or combination of both (10.7%). 8 patients (25%) from unobstructed group have detrusor instability (presumable idiopathic instability), and for the 14 patients (38%) detrusor hypocontractility was detected. CONCLUSION: Combination of the II zone of the Schafer nomogram and URA > or = 29 cmH2O increases accuracy of defining clear urodynamic obstruction, achieving better accordance with ICS nomogram, as well. It has been shown that almost two third of obstructed patients have a bladder comorbidities (detrusor instability and hypocontractility), while more than half of unobstructed patient have similar problems as a cause of the lower urinary tract symptoms.

Aged↗

PubMed2004

A nomogram for prediction of absorption rate coefficient.

BACKGROUND: Previous studies have suggested that nomogram can simplize complicated calculations of several variables. A simple nomogram was constructed to estimate absorption rate coefficient (k(a)) by using the peak time (tpeak) and the elimination rate coefficient (k(e)) of drugs administered orally. METHODS: The nomogram was based on the plasma concentration-time (C-T) curve equation and the function relation between t(peak), k(a) and k(e). A mathematical analysis was presented for the construction of single chart nomogram. To check the degree of accuracy of the developed nomogram, we used it to analyze retrospective profiles of 46 drugs and compared the ka values obtained graphically and those calculated by numerically solving the descriptive equation. In addition, we measured the carbocisteine concentration of 18 healthy volunteers by HPLC with fluorescence detection. To analyze performance error, the measured carbocisteine concentrations were compared with predicted concentrations by the ka obtained from the nomograms along with the other pharmacokinetic parameters. RESULTS: The estimated of k(a) values from nomograms were in very close proximity with the numerical values. The performance error was as follows: median performance error (MDPE) and median absolute performance error (MDAPE) were 1.32% and 18.15%, respectively. CONCLUSIONS: The developed nomogram is accurate and reliable. The size of performance error meets the demand of clinical pharmacokinetics. Therefore, the nomograms can offer another convenient and easy method for rational individualized dosage regimens.

Absorption↗

PubMed1997

Evaluation of a nomogram used to predict the pathologic stage of clinically localized prostate carcinoma.

BACKGROUND: A Nomogram based on pretreatment prostate specific antigen (PSA) level, tumor grade, and clinical stage has recently been developed and distributed to physicians. It was distributed to aid physicians in making treatment recommendations by predicting the probability of the final pathologic stage of clinically localized prostate carcinoma. The Nomogram was based on data for one patient population, and the validity of its application in general urologic practices had not yet been evaluated. METHODS: In the current study, the authors tested the performance of the Nomogram against data from their series of 697 men who underwent radical prostatectomy during the PSA era. Predictions made with the Nomogram were applied to the authors' data set, and the predictions were compared with actual outcomes of the authors' patients. A localized least-squares regression smoothing technique was used to determine whether the Nomogram was calibrated accurately for the authors' data and whether it discriminated across a full spectrum of patient characteristics. RESULTS: Many of the predicted probabilities of the Nomogram were accurate, but some were suboptimal when applied to the authors' data set. Although the Nomogram did discriminate quite well between organ-confined and nonconfined cancer, it had difficulty predicting high probabilities of seminal vesicle invasion and lymph node metastasis, which are the pathologic features with the most profound impact on prognosis. CONCLUSIONS: The Nomogram predicted organ-confined disease accurately. However, because not all of its predictions were completely calibrated when applied to the authors' data set, the authors conclude that the Nomogram may not be totally applicable to general urologic practice until further validation and possible modifications are performed.

Data Interpretation, Statistical↗

PubMed2005

Validation and adaptation of a nomogram for predicting the survival of patients with extremity soft tissue sarcoma using a three-grade system.

BACKGROUND: A nomogram for predicting long term tumor-specific death in patients with soft tissue sarcoma (STS) was developed at the Memorial Sloan-Kettering Cancer Center (MSKCC). METHODS: To assess the performance of the MSKCC nomogram, 642 consecutive patients with extremity STS who underwent surgery over a 20-year span at a single referral center were analyzed. Nomogram predictions were based on tumor size, depth, site, patient age, histologic subtype, and grade. The latter, at variance with the system in use at the MSKCC, was classified as Grade 1-3 according to the French Federation of Cancer Centers Sarcoma Group (FNCLCC) system. The statistical approach used for nomogram performance assessment was that of "validation by calibration" proposed by Van Houwelingen. RESULTS: Graphic comparison of observed and predicted sarcoma-specific survival curves showed that predictions by the nomogram were quite accurate, within 10% of actual survival for all prognostic strata. Statistical analysis showed that such predictions could be improved by employing approximately 25% shrinkage to achieve good calibration. The contribution of histologic grade was highly significant in both univariate analysis (P < 0.001) and multivariate analysis (P < 0.001), and a survival trend across the 3 grade categories was observed. Based on those findings, a nomogram that included the FNCLCC histologic grade classification was produced. CONCLUSIONS: Results of the current study confirmed that the MSKCC nomogram is a valuable tool for individual prognostic assessment. A nomogram that included the FNCLCC histologic grade classification was proposed and was validated internally.

Adolescent↗

PubMed2006

Development and validation of nomograms for predicting residual tumor size and the probability of successful conservative surgery with neoadjuvant chemotherapy for breast cancer.

BACKGROUND: Neoadjuvant chemotherapy (NACT) increases the likelihood that breast conservation therapy for breast cancer patients will be successful. There is no available nomogram to predict breast conservation after NACT. The aim of the current study was to develop and validate nomograms for predicting residual tumor size and probability of a patient becoming eligible for breast conservation surgery after NACT. METHODS: A total of 1147 patients treated at M. D. Anderson Cancer Center (Houston, TX) and the Institut Gustave Roussy (Villejuif, France) who received anthracycline with or without paclitaxel NACT were included in the analysis. Clinicopathologic data from 1 series were used to construct logistic regression models for breast conservation and residual tumor size < 3 cm after NACT and were validated on an independent series. RESULTS: The discrimination and the calibration of the nomogram for predicting the probability of residual tumor size < 3 cm after anthracycline-based NACT were good when applied to the validation set (concordance index = 0.79; U-index = 10(-3)). The discrimination of the nomogram for predicting eligibility for breast conservation therapy was also good (concordance index = 0.67). However, the calibration had to be adjusted to take into account global rates of breast conservation surgery. A second nomogram adapted to preoperative chemotherapy regimens containing paclitaxel was established. The concordance index of the nomogram for predicting breast conservation was 0.71 (P < 10(-6)) for the independent dataset and the calibration was also good. The confrontation of both nomograms showed that predictions were highly correlated (r = 0.97), suggesting that eligibility for breast conservation therapy was independent of the preoperative chemotherapy regimen used. CONCLUSIONS: Nomograms were developed for breast cancer patients who received NACT to predict residual tumor size and whether the patient would thus become eligible for breast conservation therapy. These tools may be useful when counseling patients about treatment options, and a web-based interface is now available to help guide patients and physicians in these decisions.

Anthracyclines↗