A 3-week-old boy is brought by his parents to your clinic for a well-child visit. The newborn was born at term after an uncomplicated pregnancy. He is exclusively breastfed and is thriving. Physical examination findings are normal except for jaundice. Total bilirubin is 172 μmol/L (≤100), and conjugated bilirubin is 4 μmol/L (≥5). Results of a complete blood count and reticulocyte count are within the normal range. The results of a direct antiglobulin (Coombs) test were negative. Which one of the following, if any, is the most appropriate investigation?
A 45-year-old woman presents to your clinic for follow-up regarding her asthma. She is planning to attend a cultural event that includes ceremonial burning of tobacco. Which one of the following is the best next step?
Three months ago, a physician colleague approached you in the hospital corridor for advice regarding one of his patients. You are now being named by this patient in a malpractice action. Which one of the following is the most likely reason why you may be found liable?
A patient ' s mother comes to you with a prospective cohort study linking autism to the measles, mumps and rubella vaccine. After reviewing the study carefully, you question the results because of problems with the study design and execution. Which one of the following sources of error would be most important in the study design or execution?