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.

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Name: ____________________   Date: ____________

1.Easy
testdisease presentdisease absenttotalpositive30216246abnegative20724744cdtotal50940990

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 predictive value NPV as a percentage. Round to one decimal place.

a = 30b = 216c = 20d = 724
NPV = %
2.Easy
testdisease presentdisease absenttotalpositive233198431abnegative137462599cdtotal3706601030

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 sensitivity Se as a percentage. Round to one decimal place.

a = 233b = 198c = 137d = 462
Se = %
3.Medium
testdisease presentdisease absenttotalpositive25239291abnegative3812611299cdtotal29013001590

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 = 252b = 39c = 38d = 1261
LR− =
4.Medium
peopleyears1220225902.5new cases93

Practice exercise (made-up values, not clinical guidance). In a cohort, groups of people were followed for different lengths of time (see the table: number of people and years of follow-up for each). During follow-up, 93 new cases occurred. Find the incidence rate IR per 1000 person-years. Round to one decimal place.

220 × 2 years590 × 2.5 years93 new cases
IR = per 1000 person-years
5.Hard
p (%)PPV (%)10%PPV = ?100

Practice exercise (made-up values, not clinical guidance). A screening test has a sensitivity of 72% and a specificity of 85%. It is used in a population where the prevalence is 10%. Find the positive predictive value PPV as a percentage. Round to one decimal place.

Se = 72%Sp = 85%p = 10%
PPV = %
6.Hard
p (%)PPV (%)2%PPV = ?100

Practice exercise (made-up values, not clinical guidance). A screening test has a sensitivity of 80% and a specificity of 99%. 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.

Se = 80%Sp = 99%p = 2%
PPV = %

Answer key

  1. 1. NPV = 97.3 %
  2. 2. Se = 63 %
  3. 3. LR− = 0.14
  4. 4. IR = 48.6 per 1000 person-years
  5. 5. PPV = 34.8 %
  6. 6. PPV = 62 %

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