Objectives: To identify anthracycline induced acute (within one month) and early onset chronic progressive (within year) cardiotoxicity in children younger than 16 years of age with childhood malignancies at tertiary care center of Pakistan. Design: Prospective Cohort study. Setting: Aga Khan University, Karachi, Pakistan. Participants: 110 children (aged 1 month to 16 years). Intervention: Anthracycline (Doxorubicin and/or Daunorubicin). Outcome measurements: All children who received anthracycline as chemotherapy and three echocardiographic evaluations (baseline, one month and 1 year) between July 2010 and June 2012 were prospectively analyzed for cardiac dysfunction. Statistical analysis including systolic and diastolic functions at baseline, 1 month and 1 year were made by repeated measures analysis of variance (r-ANOVA). Results: Mean age was 7444 months and 75 (68.2%) were males. Acute lymphoblastic leukemia (ALL) was seen in 70 (64%) patients. Doxorubicin alone was used in 59 (54%) and combination therapy was used in 35(32%). A cumulative dose of anthracycline <300mg>

A least squares linear regression equation was created for children undergoing chemotherapy. The explanatory (x) variable is the dosage level of Anthracycline and the response (y) variable was the left ventricular systolic diameter in millimeters. The following is a scatter plot of the data set: 1. Are there any data points that are outliers? Why are they outliers? The correlation coefficient between these two variables is r = 0.590882 The least squares regression equation is y = 0.029x + 20.46 2. Does the least squares regression equation appear to fit the data well? Why or why not?

3. What value does the least squares regression equation predict for the left ventricular systolic diameter when the Anthracycline level is 200? In other words, what does the least squares regression equation predict for y when x = 200? 4. What would the least squares regression equation predict when the Anthracycline level is

900? Would our prediction be reliable?