MCQS Online Practice Questions and Answers

Correct Answer: B

Prospective cohort study is a cohort study that follows over time a group of similar individuals (cohorts) who differ with respect to certain factors under study, to determine how these factors affect rates of a certain outcome. For example, one might follow a cohort of middle-aged truck drivers who vary in terms of smoking habits, to test the hypothesis that the 20-year incidence rate of lung cancer will be highest among heavy smokers, followed by moderate smokers, and then nonsmokers. The prospective study is important for research on the etiology of diseases and disorders. The distinguishing feature of a prospective cohort study is that at the time that the investigators begin enrolling subjects and collecting baseline exposure information, none of the subjects have developed any of the outcomes of interest. After baseline information is collected, subjects in a prospective cohort study are then followed "longitudinally," i.e. over a period of time, usually for years, to determine if and when they become diseased and whether their exposure status changes outcomes. In this way, investigators can eventually use the data to answer many questions about the associations between "risk factors" and disease outcomes. For example, one could identify smokers and non-smokers at baseline and compare their subsequent incidence of developing heart disease. Alternatively, one could group subjects based on their body mass index (BMI) and compare their risk of developing heart disease or cancer. Prospective cohort studies are typically ranked higher in the hierarchy of evidence than retrospective cohort studies and can be more expensive than a case璫 ontrol study. One of the advantages of prospective cohort studies is they can help determine risk factors for being infected with a new disease because they are a longitudinal observation over time, and the collection of results is at regular time intervals, so recall error is minimized.

Correct Answer: D

Based on the available evidence, expert opinion in the United States holds that the risks of combination contraceptive products usually outweigh the benefits before 4 weeks postpartum. Between 4 weeks and 6 months postpartum, the advantages of using the method generally outweigh the theoretical or proven risks, although the evidence of lack of effect on lactation is poor and does not include preterm or ill infants. Introduction of a combined oral contraceptive containing 30 mcg of ethinyl estradiol on day 42 or beyond may not affect milk intake or infant growth. After 6 months postpartum, combination contraceptives, including oral tablets, the transdermal patch and vaginal ring, can be used, but progestin-only methods are preferred if breastfeeding will be continued.

Correct Answer: C

In central retinal artery occlusion (CRAO) retina becomes pale and fovea. Hypertension is a major cause of CRAO. Apply direct pressure for 5-15 seconds, then release. Repeat several massage can dislodge the embolus to a point further down the arterial circulation and improve retinal perfusion.

Correct Answer: B

Angioplasty will lower the risk of mortality most for this patient. If it can be obtained within 90 minutes, angioplasty is the best therapy. Metoprolol lowers mortality but is not dependent on how soon you give it, as long as the patient receives it before going home.

Correct Answer: D

Correct Answer: B

Correct Answer: D

The most important thing to do in a woman with lower abdominal pain or tenderness is to exclude an ectopic pregnancy. Perform a urine pregnancy test first and then get a cervical culture and start therapy.

Correct Answer: D