Practice exercise (made-up values, not clinical guidance). A town has 41 500 inhabitants. At the start of a year, 376 of them have a chronic disease. During the year, 207 more people are newly diagnosed (assume nobody moves away or dies). Find the point prevalence P at the start of the year per 1000 inhabitants. Round to one decimal place.
Practice exercise (made-up values, not clinical guidance). A new test was compared with the reference standard in a study (see the 2 × 2 table). Find the prevalence in the study p as a percentage. Round to one decimal place.
Practice exercise (made-up values, not clinical guidance). A new test was compared with the reference standard in a study (see the 2 × 2 table). Find the positive likelihood ratio LR+. Round to two decimal places.
Practice exercise (made-up values, not clinical guidance). A test has a sensitivity of 63% and a specificity of 86%. Find the positive likelihood ratio LR+. Round to two decimal places.
Practice exercise (made-up values, not clinical guidance). A screening test has a sensitivity of 96% and a specificity of 88%. It is used in a population where the prevalence is 2%. Find the positive predictive value PPV as a percentage. Round to one decimal place.
Practice exercise (made-up values, not clinical guidance). A patient has a pre-test probability of 40% for a disease. A test with sensitivity 94% and specificity 77% comes back positive. Find the post-test probability p′ of the disease as a percentage. Round to one decimal place.
Full step-by-step solutions: practise this topic on examproblems.com.