[Measurement errors in medical research]

To address research questions, measuring variables are neccessary. However, every measurement is prone to different types of measurement errors. Therefore, understanding about the different types of measurement errors are a great of importance. This paper presents four types of measurement errors 1] Disagreement, which is discrepancies between the results of two or more than two measuring tools or observers 2] Random error which is a none-directional gap between the true and measured values 3] Systematic error or bias which is a directional gap between the true and measured values, and finally 4] Confounding error which changes the strength of association between dependent and independent variables in analytical studies

Electrocardiographic changes in patients with cutaneous leishmaniasis treated with systemic glucantime

<p><b>INTRODUCTION</b>Antimonial compounds are regarded as the treatment of choice for cutaneous leishmaniasis (CL). Systemic administration of these drugs has some side effects including cardio toxicity and electrocardiogram (EKG) changes. The objective of our study was to evaluate EKG changes in the patients with CL treated with systemic glucantime.</p><p><b>MATERIALS AND METHODS</b>One hundred and thirty-one patients were enrolled in this prospective study. All of the selected patients had confirmed CL and were candidates for treatment with systemic glucantime. The patients were treated with systemic glucantime and EKG was performed before, during (weekly) and 1 month after cessation of the treatment. All of the collected data were analysed using SPSS software.</p><p><b>RESULTS</b>The most common change was prolonged QT interval that was seen in 19% of the patients. ST depression occurred in 6.1% of the patients. Minimal ST elevation occurred in 3% and inverted T was observed in 7.4% of the patients. Single premature atrial contraction (PAC) and single premature ventricular contraction (PVC) occurred in 0.7% and 2.29% of patients, respectively. Bradycardia was observed in 10.6% and left bundle branch block in 0.7% of the patients. All of these changes reversed after stopping the treatment except 1 case with left bundle branch block that lasted for 1 month after the treatment.</p><p><b>CONCLUSIONS</b>Our results showed that treatment with glucantime can induce many ECG changes as QT prolongation have significant risk. We suggest that ECG monitoring should be performed in high-risk patients undergoing glucantime treatment with special attention to ECG changes mostly prolonged QT interval.</p>