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PubMed1999

Peak expiratory flow rate nomogram in Libyan schoolchildren.

The study aimed to develop a peak expiratory flow rate nomogram for Libyan children. Of 900 children randomly selected from four Tripoli primary schools, 670 (330 girls and 340 boys) with age range 4.5-14.9 years, fulfilled the selection criteria. Peak expiratory flow rate (PEFR) was recorded in a standing position using a mini-Wright peak flow meter. Anthropometric measurements, weight, height, head circumference and mid-upper-arm circumference were recorded and surface area and body mass index were calculated. Our findings showed PEFR to be significantly related to height (r = 0.74), age (r = 0.70), surface area (r = 0.64) and weight (r = 0.62): P < 0.001. The PEFR nomogram in Libyan children differed from the British standard, which highlights the need for a local reference nomogram.

Adolescent↗

PubMed2000

A nomogram to compensate for intraoperative prostate edema during transperineal brachytherapy.

PURPOSE: Prostate edema during and following prostate brachytherapy may have a negative impact on implant dosimetry. The purpose of this study was to assess the magnitude of prostate edema during the operative procedure and to develop a nomogram of isotope activity required for compensation of such intraoperative prostate volume changes. MATERIALS AND METHODS: Twenty-five consecutive patients with early-stage, localized adenocarcinoma of the prostate underwent ultrasound-guided transperineal interstitial permanent prostate brachytherapy with either iodine 125 or palladium 103. Transrectal ultrasound volume studies of the prostate were performed before and during the implant procedure. Computed tomography-based postimplant dosimetry was performed 3-4 weeks after surgery. RESULTS: A median intraoperative prostate volume increase after insertion of applicator needles of 10.4% (range 1.2-32.5%) was identified. A correlation of -0.55 (95% confidence interval -0.78 to -0.19) between the minimum dose covering 90% of the prostate volume (%D90) and the amount of edema was identified. An algorithm and nomogram was developed to calculate the extra isotope activity necessary to compensate for intraoperative edema. CONCLUSIONS: Prostate edema occurs at the time of transperineal needle placement. A negative correlation was found between the amount of edema and dose coverage of the prostate (%D90). Therefore, to cover the prostate volume adequately, additional isotope activity is required when preoperative treatment planning is performed. This nomogram can be used to compensate for such volume changes.

Adenocarcinoma↗

PubMed2004

Proposed urodynamic pressure-flow nomogram to diagnose female bladder outlet obstruction.

OBJECTIVE: To investigate female bladder outlet obstruction by urodynamics and create a nomogram to propose in clinical applications. PATIENTS AND METHODS: We investigated by urodynamic studies 200 women referred for lower urinary tract symptoms. A total of 179 patients were available for analysis: 136 served as control and 43 as obstructed. The following urodynamic variables were studied and compared in both groups: Free peak urinary flow (Free Qmax), intubated peak urinary flow (Qmax P/F), Free voiding time, pressure-flow voiding time, Detrusor pressure at peak flow rate (PdetQmax), Maximum detrusor pressure (PdetMax), Free postvoiding residual, Pressure-flow postvoiding residual. All data are presented according to descriptive statistics as mean and standard deviation (SD). Comparisons between the control and between the obstructed group were performed by means of Student's t test for equality of means, p<0.01 were considered significant. By creating ROC curves we calculated sensitivity, specificity, and positive and negative predictive values in all the patients data to derive the optimal combination of Maximum flow together with detrusor pressure at maxflow, and Maximum flow together with Maximum detrusor pressure. RESULTS: Free peak urinary flow (Free Qmax) was 26.6+/-11 ml/seconds for the control and 10.9+/-3.6 ml/seconds for the obstructed group (p<0.001). Qmax P/F were 22+/-8.7 cm water in the control group and 10+/-3.9 cm water in the obstructed group (p<0.001). Free voiding time were in both 28.2+/-15 seconds and 48+/-24 seconds (p<0.001) respectively; P/F voiding time were 41.4+/-21 seconds and 78.2+/-52 seconds (p<0.001) respectively. PdetQmax in control and obstructed group were 17.2+/-11.3 and 27.6+/-12.5 cm water (p<0.001) respectively. PdetMax were 25.2+/-14.0 and 39.4+/-18.9 cm water (p<0.001) respectively. Free postvoiding residual 25.1+/-37.4 and 74.6+/-79.3 cc (P<0.001). P/F postvoiding residual were respectively 24.9+/-44.7 and 96.0+/-102.6 cc (p<0.001). All the differences among the variables investigated in both groups were statistically significant. We calculated sensitivity, specificity, and positive and negative predictive values. According to receiver operating characteristics (ROC) curve analysis, the overall combining values of free max flow rate of 13 ml/sec or less and detrusor pressure at max flow rate of 22 cm water or greater we obtained a sensitivity of 55.8%, a specificity of 96.3%, a positive predictive value of 82.8% and a negative predictive value of 87.3%. Moreover we combined Max flow rate of 13 ml/sec and Maximum detrusor pressure of 38 cm water to obtain a sensibility of 48.8%, a specificity of 99.3%, a positive predictive value of 95.5% and a negative predictive values of 86%. CONCLUSIONS: Diagnosing female BOO is a challenge condition and an accepted pressure-flow nomograms are still missing. We propose our nomogram as a valid and reliable tool to investigate female bladder outlet obstruction.

Female↗

PubMed1983

Blood acid-base curve nomogram for immature domestic pigs.

The purpose in this study was to characterize the acid-base status of arterial blood from healthy young domestic swine and to construct an acid-base curve nomogram appropriate to such animals. Accordingly, 40 immature, 20- to 31-kg domestic pigs were used to establish acid-base characteristics for arterial blood. Samples were collected from chronically implanted catheters while the animals were maintained under steady-state, near-basal conditions. At a measurement temperature of 38 C, pH averaged 7.496; PCO2, 40.6 mm Hg; [HCO3-], 31.6 mEq/L; PO2, 79.1 mm Hg; hemoglobin, 9.65 g/dl; hematocrit, 0.29; plasma albumin, 25.3 g/L; plasma globulin, 32.3 g/L; and plasma buffer base, 45.4 mEq/L. Hourly measurements over a 6-hour period in 6 of these pigs showed a small, but significant decrease in PO2 with time, but no significant change in acid-base status. The data showed that nomograms or other procedures based on blood characteristics of men were invalid when used to estimate base excess concentration of blood from young pigs. The normal pH of arterial blood was higher in immature pigs than in men; thus, reference values defining zero base excess were not equivalent in men and pigs. Constant PCO2 titrations were performed on arterial samples taken from 10 additional pigs, and the data were used to construct an acid-base curve nomogram in which zero base excess was defined for blood with a pH of 7.50 and a PCO2 of 40 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗

PubMed1981

Analysis of methods to construct nomograms in uroflow studies.

A Monte Carlo simulation study to compare the effect of population form on three methods of nomogram construction was performed by taking 2000 random samples of size 5, 20, 50, 100, and 200 from populations with known percentiles. The 10th percentile was estimated by each of the three construction procedures. The three procedures compared were the upper 95 per cent nonparametric tolerance limit technique, the usual percentile approach, and a method which assumes a Gaussian (normal) distribution. Tenth percentile nomograms, classified by volume voided, were calculated by each of the three procedures for maximum flow rate determinations from 356 normal males of ages 1 to 12 years with body surface areas less than 1.1 m2. Nomograms of the three methods are validated with evaluations from two other groups of male children consisting of known abnormals with radiologically proven urethral obstructions and known normals who had repeated at home uroflow rates. The nonparametric tolerance limit approach gives conservative estimates and is superior in all cases from the standpoint of reducing false-negative results.

Child↗

PubMed1995

The successful application of a heparin nomogram in a community hospital.

BACKGROUND: Heparin administration by physicians can vary greatly, and this variance can result in ineffective anticoagulation and reduced effectiveness of treatment. OBJECTIVE: To examine the use of a heparin nomogram in two community hospitals to validate its effect on anticoagulation parameters and to determine its influence on length of hospital stay. METHODS: Prenomogram and postnomogram intervention in two community hospitals in Sudbury, Ontario. All patients who presented and were admitted to the hospitals between 1991 and 1994 with a confirmed primary diagnosis of deep vein thrombosis and/or pulmonary embolism were eligible for the study. A heparin nomogram was instituted in April 1993 for treatment of deep vein thrombophlebitis and pulmonary embolism in hospitalized patients. The study patients were designated as prenomogram or postnomogram. Anticoagulation parameters (time to therapeutic activated partial thromboplastin time), number of diagnostic tests, percentage of times within the therapeutic range, and length of hospital stay were recorded for both groups. RESULTS: A total of 326 patients were identified from the database; 163 (50%) met the inclusion criteria. Patients in both groups appeared to be similar. Adequate anticoagulation was achieved faster (17.9 hours postnomogram vs 48.8 hours prenomogram; P < .001) and remained subtherapeutic less frequently in the postnomogram group (number of activated partial thromboplastin time tests below the therapeutic window; 56% prenomogram vs 28% postnomogram; P < .001). There were no differences between the groups with respect to length of stay (11.3 days prenomogram vs 10.9 days postnomogram; P = .60). More activated partial thromboplastin time tests were ordered in the postnomogram group (15.6 postnomogram vs 12.7 prenomogram; P = .001); however, fewer prothrombin time tests were ordered in the postnomogram group. CONCLUSIONS: A heparin nomogram was successfully used in a community hospital without a structured hematology-thrombosis service. Therapeutic anticoagulation was achieved faster and maintained more frequently, with less logistical problems, with this protocol. However, additional measures may be required to reduce the length of hospital stay.

Adult↗

PubMed1993

A nomogram for screening low birth weight and large for gestational age babies for use in primary health care centres.

In this prospective study, maternal weights per gestational age were recorded on 600 randomly selected gravid women attending regular antenatal clinics until delivery of their babies. This paper explains how the knowledge of these weights were used to produce a pregnancy nomogram for prenatally screening mothers who are likely to deliver term (37-41 weeks). Low birth weight (< or = 2500g) and large for gestational age (> or = 3800g) babies in the community. The nomogram gave a sensitivity of 80.1%, a specificity of 97.9%; a predictive value of a positive test of 87.9% and a predictive value of a negative test of 96.3%. The lower cadre workers were able to successfully utilize the nomogram.

Birth Weight↗

PubMed1994

[Assessment of parathyroid gland function: predictive value of a nomogram].

Recent developments in measurement of intact parathormone (PTH) has enabled to generate a nomogram for parathyroid function. Blood levels of PTH can thus be interpreted in relation to calcemia. Intact PTH and calcium were assayed in blood from 99 healthy subjects studied under fasting conditions; 26 subjects were also studied during hyper- and hypocalcemia, induced by calcium and EDTA infusions, respectively. Serum levels of intact PTH which had been obtained in 99 patients were then analysed retrospectively by comparison with the nomogram. Patients whose intact PTH levels lie above the normal zone of the nomogram produce too much PTH relative to the blood calcium level (hyperparathyroidism); those falling under the normal zone produce too little (hypoparathyroidism).

Adolescent↗

PubMed1994

[Flow index: a substitute for uroflow nomograms?].

One hundred and twenty-nine flowmetries from an equal number of male patients with urinary obstructive symptoms have been analyzed, and the data provided by Siroky's nomogram compared to the flow ratios. Flow ratio was considered compatible with obstruction if below 0.80, which in turn correlated to -2 DE in Siroky's nomogram. Agreement between both parameters was noted in 95% cases (p < 0.05). The use of a flow ratio as a substitute for Siroky's nomogram to evaluate urinary obstructive disease would be justified by the easiness of interpretation, since it avoids translation of maximum flow and mean flow data to a plot. Flowmetry should only be considered determinant with clearly obstructive values.

Adolescent↗

PubMed1993

A comparison between nomogram vs. trial fitting of rigid gas permeable contact lenses.

To determine the differences between prescribing a trial fitted vs. nomogram (System 10) selected rigid gas permeable contact lens, 42 subjects were fit with one lens design on one eye and the other lens design on the opposite eye. Subjective responses for comfort and vision, objective signs of central corneal clouding, conjunctival injection, post keratometry readings, 3-9 staining, over-refraction, post refraction and lens position were ranked and assigned to success levels for each eye. Subjects were evaluated at 1 week, 1 month, and 3 months. The first fit success rates were 92 percent for the trial fit and 86 percent for the nomogram fit. The trial fit lens attained significantly better outcomes in individual categories of comfort and over-refraction. It was noted that the lens diameters differed significantly and a large percentage of both types of lenses benefited from a slight blend and edge modification. Although trial fitting remains the method of highest success, nomogram fitting (using System 10) appears consistent enough to consider it an option for certain practice situations.

Adolescent↗

PubMed1996

Prescribing hemodialysis using a nomogram approach to urea kinetic modelling.

Several studies have clearly shown that the dose of dialysis is a determining factor for the well-being of dialysis patients. These studies have also suggested that doses of dialysis represented by Kt/V of about 1.4 should be optimal doses. This dose must be measured at the time it is delivered, since for various reasons, the delivered dialysis is often less than the prescribed dose. This report describes a series of nomograms that can be used to estimate the first hemodialysis prescription, to verify the amount of dialysis delivered to the patient, and to estimate the protein catabolic rate. These nomograms should be useful in those dialysis centers where, for one reason or another, computerized urea modelling is not a routine. The nomograms in the present report should be used for evaluating the adequacy of conventional hemodialysis.

Body Height↗

PubMed1997

Nomogram for assessment of restoration of a positive overjet in unilateral cleft lip and palate.

In 92 patients with unilateral cleft lip and palate investigated on a long-term basis correlation-regression analysis of the development of overjet according to the development of interalveolar relations assessed in a defined method from X-ray films at the ages of 5, 10, 15 years and in adult age was implemented. The limits comprising 95% of the assembled data were also defined. Based on this analysis a formerly elaborated nomogram for age 10-15 years was extended for the whole postnatal period. Nomogram makes it possible to estimate from a single X-ray cephalometric parameter the risk of failure of the restoration of a positive overjet according to the age of the patient. The system defines critical boundaries which must be achieved for safe restoration of a positive overjet and makes it possible to check the course of treatment. The simple work with the nomogram and readily obtainable baseline data (age and X-ray cephalometric parameter on the interalveolar relations) make its application in clinical practice possible. It can serve as part of the documentation of the patient's therapy.

Adolescent↗

PubMed2007

A nomogram for predicting osteoporosis risk based on age, weight and quantitative ultrasound measurement.

INTRODUCTION: Quantitative ultrasound measurement (QUS) or clinical risk index alone are not reliable tools for the identification of women with osteoporosis. This study examined the prognostic value of combined QUS and clinical risk index for predicting osteoporosis risk in Thai women. METHODS: The study was designed as a cross-sectional investigation with 300 women of Thai background, aged between 38 and 85 years (mean age: 58). Femoral neck bone mineral density (BMD) was measured by DXA (Hologic QDR-4500; Bedford, MA, USA). A femoral neck BMD T-scores <or= -2.5 was defined as "osteoporosis"; otherwise, "non-osteoporosis". QUS was measured by Achilles+ (GE Lunar, Madison, WI, USA) and converted to T-score. Three models for predicting osteoporosis were considered: model I included age, weight and QUS, model II included age and weight, and model III included only QUS. The prognostic performance among the models was assessed by the area under the receiver operating characteristic curve (AUC). RESULTS: The prevalence of osteoporosis was 12.7% (n=38/300) by femoral neck BMD. Age, weight and QUS were each significantly associated with osteoporosis risk. The AUC+/-SE value for model I was 0.86 +/- 0.03, which was significantly higher (p=0.02) than that for model II (AUC = 0.80 +/- 0.04) or model III (AUC = 0.79 +/- 0.04). Based on the estimated parameters of model I, a nomogram was constructed for predicting osteoporosis. CONCLUSION: These data suggest that the combination of QUS and age and weight could significantly improve the prognosis of osteoporosis in Asian women, and that the nomogram can assist primary care physicians in the identification of high-risk women.

Adult↗

PubMed2006

Use of nomograms as predictive tools in bladder cancer.

Bladder cancer is a common genitourinary malignancy that demonstrates a great variation in risk of tumor recurrence and progression following treatment. The dramatic differences in clinical behavior dictate vastly differing treatments, which may range from simple surveillance to combination radical surgery with systemic chemotherapy. For non-muscle invasive bladder cancer prediction of the risk of recurrence and progression is necessary to assess the need for intravesical therapy and possible early cystectomy. In contrast, prediction of advanced disease response to primary treatment such as cystectomy and the response to systemic chemotherapy plays an important role in treatment assignment for patients with muscle invasive disease. To estimate these risk traditional risk grouping schemes such as the present TNM staging system has been used to guide patient treatment. More recently, improved prognostic tools such as nomograms have been developed to provide a more accurate assessment of outcomes. Clinicians are enthusiastically working to utilize these statistical methods in bladder cancer. We summarize the current status of outcome predictive models for bladder cancer; and focus particularly on the ability of nomograms to predict disease recurrence, progression, and patient survival.

Algorithms↗

PubMed2005

Nonsentinel node metastasis in breast cancer patients: assessment of an existing and a new predictive nomogram.

BACKGROUND: The accurate prediction of nonsentinel node (NSN) metastasis in breast cancer patients remains uncertain. METHODS: The medical records of 574 breast cancer patients from 2 different institutions (Mayo Clinic and University of Michigan) with sentinel lymph node biopsy examination and completion axillary lymph node dissection were reviewed for multiple clinicopathologic variables. The Memorial Sloan Kettering Cancer Center nomogram performance for prediction of NSN metastases was assessed. A new model was developed with clinically relevant variables and possible advantages. RESULTS: The Memorial Sloan Kettering Cancer Center nomogram predicted the likelihood of NSN metastasis with an area under the receiver operating characteristic curve of .72 and .86. For predicted probability cut-off points of 5% and 10%, the false-negative rates were 0% and 14% (Mayo), and 17% and 11% (Michigan). A new model was developed with similar area under the curve but lower false-negative rates for low-probability subgroups. CONCLUSIONS: Predictive models for NSN tumor burden are imperfect.

Adult↗

PubMed2005

Evaluation of a breast cancer nomogram for prediction of non-sentinel lymph node positivity.

AIMS: This study evaluates the breast cancer nomogram (BCN), an online tool developed by Memorial Sloan-Kettering Cancer Center to determine the rate of non-SLN positivity, in an independent cohort of SLN positive patients. MATERIAL AND METHODS: Available data between 02/2000 and 06/2004 in two prospective databases, 749 cases had successful SLN biopsy including 149 axillary-SLN metastases study cases. These cases had accurately graded tumours up to 9 cm in size and CAD with a minimum total 10 nodes removed. Histopathological assessment of nodes included hematoxylin and eosin staining and/or immunohistochemistry. Computerized BCN was used to estimate probability of non-SLN positivity and compared with actual probability after grouping into deciles. RESULTS: The trend of actual probability in various decile groups was comparable to the predicted probability. An area under the receiver operating characteristic curve was 0.75 as compared to 0.76 in the original study. CONCLUSION: Although this study is small, the results are encouraging and suggest the nomogram is a useful tool to estimate the likelihood of positive axillary non-SLN. However, variations in pathological assessment between centres are the major impediment to widespread application of BCN. If SLN positive patients decline the standard recommendation of CAD or entry into clinical trials evaluating the significance of CAD then the BCN could help in decision making.

Adult↗

PubMed2005

Development and internal validation of a nomogram predicting the probability of prostate cancer Gleason sum upgrading between biopsy and radical prostatectomy pathology.

OBJECTIVE: Previous reports indicate that as many as 43% of men with low grade PCa at biopsy will be diagnosed with high-grade PCa at RP. We explored the rate of upgrading from biopsy to RP specimen in our contemporary cohort, and developed a model capable of predicting the probability of biopsy Gleason sum upgrading. MATERIALS AND METHODS: The study cohort consisted of 2982 men treated with RP, with available clinical stage, serum prostate specific antigen and biopsy Gleason scores. These clinical data were used as predictors in multivariate logistic regression models (LRM) addressing the rate of Gleason sum upgrading between biopsy and RP pathology. LRM regression coefficients were used to develop a nomogram predicting the probability of Gleason sum upgrading and was subjected to 200 bootstrap resamples for internal validation and to reduce overfit bias. RESULTS: Overall, 875 patients were upgraded (29.3%). In multivariate LRMs, all predictors were highly significant (all p values <0.0001). Bootstrap-corrected predictive accuracy of the nomogram predicting the probability of Gleason sum upgrading between biopsy and RP was 0.804. CONCLUSION: We developed a highly accurate clinical aid for treatment decision-making. It may prove useful when the possibility of a more aggressive Gleason variant may change the treatment options.

Biopsy↗

PubMed2005

A gait nomogram used with fuzzy clustering to monitor functional status of children and young adults with cerebral palsy.

We have developed a gait nomogram based on dynamic similarity to characterize and compare neuromuscular function. We used temporal-distance data based on 669 normal participants (age range 5 to 98 years), and 78 children and young adults with spastic diplegia (43 males, 35 females; mean age 10 y 8 mo, standard deviation 3 y 11 mo, range 5 to 20 y), all of whom were independent ambulators. A new statistical algorithm known as fuzzy clustering was implemented and five cluster centres were identified, each representing distinct walking strategies adopted by children with cerebral palsy. Using just three easily obtained parameters--leg length in metres, stride length in metres, and cadence in steps per minute--our program calculates a child's dimensionless step length and step frequency, generates the individual's membership values for each of the five clusters, and plots the gait nomogram. The clinical utility of our approach has been demonstrated for two test participants with spastic diplegia, using pre- and postoperative data (one neurosurgical and one orthopaedic), where changes in membership of the five clusters provide objective measures of improvement in their neuromuscular function.

Adolescent↗