Iranian Journal of

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Background: The aim of this study was to determine the level of agreement between the impaired fasting glucose (IFG) and abnormal glucose tolerance before and after application of the new IFG definition and to evaluate the impact of adding common clinical data on this agreement.
Methods: A cross sectional population based study was carried out in an Iranian urban population which enrolled 8766 men and women over 20 years. Fasting and 2-hour plasma glucose were measured in all subjects excluding those with previously diagnosed diabetes and fasting plasma glucose ≥126 mg/dl. The diagnostic parameters and kappa coefficient between the previous and revised definitions of IFG for detecting impaired glucose tolerance (IGT) and dysglycemia (IGT and diabetes) were calculated. Logistic regression and ROC curve analysis were used to determine the independent clinical risk factors and their optimal cut-points associated with IGT and dysglycemia. Results: After using the new criteria, sensitivity of IFG for detecting IGT or dysglycemia increased but specificity and positive likelihood ratio (LR+) decreased and the κ slightly improved (0.16 to 0.29 for IGT and 0.24 to 0.35 for dysglycemia). Adding the clinical data to the revised criteria considerably improved the agreement between IFG with IGT and dysglycemia (κ increased from 0.286 to 0.470 for IGT and from 0.354 to 0.574 for dysglycemia). This also increased the LR+ from 3.86 to 14.5 and from 4.46 to 17.4 respectively for detecting IGT or dysglycemia.
Conclusion: The new IFG definition in combination with common clinical risk factors most likely predicts IGT and dysglycemia.

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 Background: Microalbominuria (MA) is early presentation of renal damage which acts as an independent factor of cardiovascular events in these patients. There are various methods for sampling and also different laboratory tests to measuring albominuria. The aim of this study was to compare of different urine collection methods for measuring albominuria using immunoturbidometry assay which has acceptable accuracy and sensitivity after HPLC (High Performance Lipid Chromathography).

Methods: Forty seven diabetic patients were selected for a cross-sectional study in 2006. For all patients 24-h urine sample were collected, also an overnight urine sample (8 hour long) and spot urine sample (morning time) was provided in the next day. The level of albumin in all samples were measured via immunoturbidometry assay. Then the results of agreement coefficient were accounted and comprised with each others.

Results: In this study 47 patients were selected which 46 of them were type 2 and one of them type 1 diabetic. Our results revealed significant correlation between all methods. In addition agreement coefficient (kappa) was accounted for all methods, time 24-h urine in comparison with 8 hours overnight urine, timed 24-h urine in comparison with spot urine and overnight urine samples in comparison with spot urine which were 0.876, 0.936 and 0.807 respectively.

Conclusion: Regarding significant agreement for screening of microalbominuria between different collecting methods, we suggest 8-h overnight or spot urine sampling carry out instead of 24-h urine collection.

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In medical studies, measures are required to reveal the effect of exposures and interventions and also the precision of measurements. This paper aimed to introduce the measures of effect and agreement and inferences about them in these studies. Principles and method of calculating measures of effect and agreement and inference about them were presented for all types of medical studies taking into account the relevant considerations. To assess the effect of risk factors on outcomes in case-control and cohort studies, and to determine the relevant effect, the attributable risk and fraction in the exposed group and population were used along with their confidence intervals. Also the relative risk reduction, absolute risk reduction and number needed to treat were applied as the measures of effect of intervention in the interventional studies especially in trails. The sensitivity, specificity and related measures along with their confidence intervals were computed for diagnostic accuracy and screening studies. In addition it is needed to evaluate the precision of measurements using standard error of measurements, ICC, Altman and Bland’s limits of agreement and Lin’s concordance correlation coefficient for quantitative variables and using kappa and weighted kappa for nominal and ordinal variables. In each of these situations the results of research based examples were presented along with the methods of their calculations.To assess the measures of effect and agreement, the mentioned analyses are recommended considering the situation and purpose of the study.