Browsing by Person "Raza, Zahid"

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Development of a prognostic model for fistula maturation in patients with advanced renal failure
(2012-05-24) Siddiqui, Muhammad A.; Raza, Zahid; Santos, Derek; Ashraff, Suhel; Carline, Tom
Introduction This study aimed to explore the role of haematological markers and predictive factors on the maturation of arteriovenous fistulae in patients who underwent vascular access surgery at the Royal Infirmary of Edinburgh. Methods Retrospective analysis of 300 patients was retrieved who had undergone fistula creation between 2006 and 2009. A predictive model was developed using backward stepwise logistic regression. The model discrimination was assessed by the receiver operating characteristics curve and its calibration by the Hosmer and Lemeshow goodness of fit test. Results Three variables were identified which influenced fistula maturation. Gender - Males were twice as likely to undergo fistula maturation, compared to that of females (odds ratio [OR] 0.514; 95% confidence interval [CI] 0.308 to 0.857). Peripheral Vascular Disease - Patients with no evidence of PVD were three times more likely to mature their fistula (OR 3.140; 95% CI 1.596 to 6.177). Vein Size - A pre operative vein diameter > 2.5mm resulted in a five fold increase in fistula maturation compared to a vein size less than 2.5mm (OR 4.532; 95% CI 2.063 to 9.958). There was a good calibration as indicated by Hosmer and Lemeshow goodness of fit test (P=0.79) and the c-index was 0.677. Conclusion Gender, PVD and vein size are useful predictors of arteriovenous fistulae maturation. The clinical utility of these risk categories in the maturation of arteriovenous fistulae requires further clinical evaluation in a prospective study.
Development of a prognostic model for stump healing in major lower limb amputation among the diabetic population
(MDPI, 2021-07-12) Ashraff, Suhel; Siddiqui, Muhammad; Carline, Tom; Rush, Robert; Santos, Derek; Raza, Zahid
Background: This study aimed to explore the effect of haematological markers as well as patient characteristics on stump healing in patients who underwent a lower limb amputation procedure. In addition, a practical model regarding factors that affected stump healing was developed. Methods: Patients who underwent a major lower limb amputation (above knee and below knee) at the Royal Infirmary of Edinburgh from the period of 2007 to 2010 were included in this study. A prognostic model utilizing backward stepwise logistical regression was developed to measure the probability of lower limb stump healing. The relationship between the dependent and independent variables was identified using univariate and multivariate logistic regression. Results: Three variables, namely serum sodium, serum creatinine and serum high density lipid cholesterol were identified which influenced stump healing. Patients with normal serum sodium were 75% more likely to have lower limb stump healing compared to that of patients with abnormal serum sodium (odds ratio [OR] 1.756; 95% confidence interval [CI] 1.048–2.942). Patients with normal serum creatinine were 66% more likely to have their stump healed (OR 1.664; 95% CI 0.94 to 2.946). The healing rate of patients with a normal level of serum high density lipid cholesterol was 75%, in contrast to patients with an aberrant level of serum high density lipids cholesterol (OR 1.753; 95% CI 1.061 to 2.895). The effectiveness of the retrospective stump-healing model was demonstrated by the area under the ROC curve (0.612), which was supported by the Hosmer and Lemeshow goodness-of-fit test (p = 0.879). Conclusions: Serum sodium, serum high density lipid cholesterol and serum creatinine have a strong correlation with lower limb stump healing. However, serum sodium and serum high density lipid cholesterol secondary to multiple co-morbidities in this cohort group could be altered secondary to disease pathology itself.
Development of a prognostic model for stump healing in patients with advanced atherosclerosis
(2012-05-24) Ashraff, Suhel; Raza, Zahid; Santos, Derek; Siddiqui, Muhammad A.; Carline, Tom
Introduction This study aimed to explore the role of haematological markers and predictive factors on the stump healing in patients who underwent lower extremity amputation surgery at the Royal Infirmary of Edinburgh. Methods Retrospective analysis of 300 patients was retrieved who had undergone lower extremity amputation surgery between 2006 and 2010. A predictive model was developed using backward stepwise logistic regression. The model discrimination was assessed by the receiver operating characteristics curve and its calibration by the Hosmer and Lemeshow goodness of fit test. Result Three variables were identified which influenced stump healing. Serum Sodium - The lower limb stump healing was 75% likely in patients with normal serum sodium compared to that of patients with abnormal serum sodium (odds ratio [OR] 1.756; 95% confidence interval [CI] 1.048-2.942) Serum Creatinine- Patients with normal serum creatinine were 66% more likely to have their stump healed (OR 1.664; 95% CI 0.94 to 2.946) Serum High Density Lipoproteins - A normal serum HDL resulted in a 75% more likely chance of healing compared to those with abnormal serum HDL (OR 1.753; 95% CI 1.061 to 2.895). There was a good calibration as indicated by Hosmer and Lemeshow goodness of fit test (P=0.879) and the c-index was 0.612. Conclusion Serum Sodium, Serum High Density Lipids and Serum creatinine are useful predictors of lower limb stump. The clinical utility of these risk categories in the healing of a lower limb stump requires further clinical evaluation in a prospective study.
Development of prognostic model for fistula maturation in patients with advanced renal failure
(BioMed Central, 2018-03-07) Siddiqui, Muhammad A.; Ashraff, Suhel; Santos, Derek; Rush, Robert; Carline, Tom; Raza, Zahid
Background: This study aimed to explore the role of patient's characteristic and haematological factors as predictive on the maturation of arteriovenous fistulae in patients who underwent vascular access surgery at the Royal Infirmary of Edinburgh. Methods: Retrospective data from 300 patients who had undergone fistula creation between February 2007 and October 2010 was examined. A predictive logistic regression model was developed using the backward stepwise procedure. Model performance, discrimination and calibration, was assessed using the receiver operating characteristics (ROC) curve and Hosmer and Lemeshow goodness of fit test. Results: Three variables were identified which independently influenced fistula maturation. Males were twice as likely to undergo fistula maturation, compared to that of females (odds ratio (OR) 0.514; 95% confidence interval (CI) 0.308-0.857), patients with no evidence of peripheral vascular disease (PVD) were three times more likely to mature their fistula (OR 3.140; 95% CI 1.596-6.177) and a pre-operative vein diameter > 2.5 mm resulted in a fivefold increase in fistula maturation compared to a vein size less than 2.5 mm (OR 4.532; 95% CI 2.063-9.958). The model for fistula maturation had fair discrimination as indicated by the area under the ROC curve (0.68; 95% CI 0.615-0. 738) but good calibration indicated by Hosmer and Lemeshow test (p = 0.79). Conclusion: Gender, PVD and vein size are independent predictors of arteriovenous fistula maturation. The clinical utility of these risk equation in the maturation of arteriovenous fistulae requires further validation in the newly treated patients.
Predictive parameters of arteriovenous fistula maturation in patients with end-stage renal disease
(Korean Society of Nephrology, 2018-09-30) Siddiqui, Muhammad A.; Ashraff, Suhel; Santos, Derek; Rush, Robert; Carline, Tom; Raza, Zahid
Background:The objevctive of the present study was to explore the potential influence of blood markers and patient factors such as risk factors, kidney function profile, coagulation profile, lipid profile, body mass index, blood pressure, and vein diameter on the maturation of arteriovenous fistula (AVF) in patients with end-stage renal disease. Methods:Retrospective data from 300 patients who had undergone AVF creation at the Royal Infirmary of Edinburgh were examined. A predictive logistic regression model was developed using a backward stepwise procedure. Model performance, discrimination, and calibration were assessed using the receiver operating characteristic (ROC) curve and Hosmer-Lemeshow goodness-of-fit test. The final model was externally validated by 100 prospective patients who received a new fistula at the Royal Infirmary of Edinburgh. Results:A total of 400 (300 retrospective and 100 prospective) patients were recruited for this study, with a mean age of 60.14 ± 15.9 years (development set) and 58 ± 15 years (validation set), respectively (P = 0.208). Study results showed that males were twice as likely to undergo fistula maturation as females, while patients with no evidence of peripheral vascular disease (PVD) were three times more likely to mature their fistula and a preoperative vein diameter > 2.5 mm resulted in a fivefold increase in fistula maturation as compared with a vein size of less than 2.5 mm. The model for fistula maturation had fair discrimination, as indicated by the area under the ROC curve (0.68), but good calibration as indicated by the Hosmer-Lemeshow test (P = 0.79). The area under the receiver operating curve for the validation model in the validation set was 0.59. Similarly, in the validation set, the Hosmer-Lemeshow statistic indicated an agreement between the observed and predicted probabilities of maturation (P > 0.05). Conclusion:Gender, PVD, and vein size are independent predictors of AVF maturation. The clinical utility of these risk categories in the maturation of AVF requires further evaluation in longer follow-up.