Evidence-based practice statistics worksheet with answers

Free printable Evidence-based practice statistics worksheet: 6 problems from easy to exam level, with an answer key. Print it or save it as a PDF.

For teachers: free to print, copy and use in class. Every new worksheet has new values and its own answer key. A link to ExamProblems on your course page is appreciated.

Name: ____________________   Date: ____________

1.Easy
testdisease presentdisease absenttotalpositive31266297abnegative9474483cdtotal40740780

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 accuracy Acc as a percentage. Round to one decimal place.

a = 31b = 266c = 9d = 474
Acc = %
2.Easy
testdisease presentdisease absenttotalpositive21838256abnegative6262124cdtotal280100380

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 specificity Sp as a percentage. Round to one decimal place.

a = 218b = 38c = 62d = 62
Sp = %
3.Medium
testdisease presentdisease absenttotalpositive152105257abnegative38285323cdtotal190390580

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 negative likelihood ratio LR−. Round to two decimal places.

a = 152b = 105c = 38d = 285
LR− =
4.Medium
casescontrolsexposed6766abnot exposed203324cd

Practice exercise (made-up values, not clinical guidance). A case-control study compares 270 patients with a disease (cases) and 390 people without it (controls). The table shows how many in each group were exposed to a risk factor. Find the odds ratio OR for the exposure. Round to two decimal places.

a = 67b = 66c = 203d = 324
OR =
5.Hard
testdisease presentdisease absenttotalpositive?negativetotal10 000

Practice exercise (made-up values, not clinical guidance). 10 000 people are screened with a test of sensitivity 74% and specificity 76%. The prevalence of the disease is 4%. How many false-positive results FP are expected?

N = 10 000p = 4%Se = 74%Sp = 76%
FP =
6.Hard
p (%)PPV (%)3%PPV = ?100

Practice exercise (made-up values, not clinical guidance). A screening test has a sensitivity of 76% and a specificity of 86%. It is used in a population where the prevalence is 3%. Find the positive predictive value PPV as a percentage. Round to one decimal place.

Se = 76%Sp = 86%p = 3%
PPV = %

Answer key

  1. 1. Acc = 64.7 %
  2. 2. Sp = 62 %
  3. 3. LR− = 0.27
  4. 4. OR = 1.62
  5. 5. FP = 2304
  6. 6. PPV = 14.4 %

Full step-by-step solutions: practise this topic on examproblems.com.