• How to study for Step 1 Usmle

    How to Study for Step 1 Usmle

    Step 1 is probably going to be one of the most difficult exams you will write in your medical career. Scoring well on this exam is necessary for matching into your residency of choice. So, the question is, what is the best approach to ace your exam? We’ve looked at advice and comments from past test takers to come up with the best test resources, schedules, and study approaches. First Aid for the USMLE Step 1 To ensure that you cover all the most important topics, you will need a a general review book. First Aid for the USMLE Step 1 is the best book for this. It lacks detailed…

  • Biostatistics

    Receiver Operating Characteristics (ROC) curve

    What is an ROC curve? ROC curves are made to help decide on a good cutoff point for a test. If the cutoff is very high, there will be too many false negatives but few false positives. Whereas, if the cutoff is too low there will be too many false positives and few false negatives. To do this, the true positive rate (sensitivity) and false positive rate (1 – specificity) of the test are calculated for several possible cutoff points. Then these are plotted to create the ROC curve and the area under the curve can be measured to determine the overall accuracy of a test. Notice that the ROC…

  • Biostatistics

    Biostatistics Questions

    A new blood test to detect prostate cancer is evaluated in 300 male volunteers. A needle biopsy of the prostate gland is done on all men with serum prostate-specific antigen concentrations greater than 5 ng/mL (N<4). One hundred men undergo biopsy procedures; 90 are found to have prostate cancer, and five are found to have chronic prostatitis. Which of the following is necessary to calculate the sensitivity of this test? (A)  Incidence of chronic prostatitis in the general population (B)  Number of men with test results greater than 5 ng/mL and a normal biopsy specimen (C)  Prevalence of chronic prostatitis in the general population (D)  Prostate biopsies of men with…