Study design

Diagnostic performance study requirements and dataset layout.

Requirements

A qualitative or quantitative variable of the measured values or indications (positive/negative) of the diagnostic test.
A qualitative variable indicating the true state (positive/negative) of each subject.

Dataset layout for a single test

Use a column for the true state variable (State), and a column for the test measured values (Test); each row has the values of the variables for a case (Subject).

Subject (optional)	State	Test
1	Diseased	121
2	Diseased	118
3	Diseased	124
4	Diseased	120
5	Diseased	116
6	…	…
7	Healthy	100
8	Healthy	115
9	Healthy	102
10	Healthy	98
11	Healthy	118
…	…	…

Dataset layout for paired tests

Use a column for the true state variable (State), and a column for each of the test measured values (Test 1, Test 2); each row has the values of the variables for a case (Subject).

Subject (optional)	State	Test 1	Test 2
1	Diseased	121	86
2	Diseased	118	90
3	Diseased	124	91
4	Diseased	120	99
5	Diseased	116	89
6	…	…	…
7	Healthy	100	70
8	Healthy	115	80
9	Healthy	102	79
10	Healthy	98	87
11	Healthy	118	90
…	…	…

Dataset layout for independent tests

Use a column for the true state variable (State), a column for the factor (test or group indicator), and a column for the test measured values (Test); each row has the values of the variables for a case (Subject).

Subject (optional)	State	Test/Group ID	Test result
1	Diseased	1	121
2	Diseased	1	118
3	Diseased	1	124
4	Diseased	1	120
5	Diseased	1	116
6	Healthy	1	100
7	Healthy	1	115
8	Healthy	1	102
9	Healthy	1	98
10	Healthy	1	118
11	…	…	…
12	Diseased	2	86
13	Diseased	2	90
14	Diseased	2	91
15	Diseased	2	99
16	Diseased	2	89
17	Healthy	2	70
18	Healthy	2	80
19	Healthy	2	79
20	Healthy	2	87
21	Healthy	2	90
…	…	…	…

Dataset layout for a single binary test

Use a column for the true state variable (State), and a column for the test indications (Test); each row has the values of the variables for a case (Subject).

Subject (optional)	State	Test
1	Diseased	P
2	Diseased	P
3	Diseased	P
4	Diseased	N
5	Diseased	P
6	Healthy	N
7	Healthy	N
8	Healthy	N
9	Healthy	N
10	Healthy	N
…	…	…

Frequency form dataset layout for a binary test

Use a column for the true state variable (State), and a column for the test indications (Test) and a column for the number of cases (Frequency); each row has the values of the variables and the frequency count.

State	Test	Count
Diseased	Positive	3
Diseased	Negative	1
Healthy	Positive	0
Healthy	Negative	5

Frequency form dataset layout for 2 independent binary tests

Use a column for the true state variable (State), a column for the factor (test or group indicator), a column for the test indications (Test) and a column for the number of cases (Frequency); each row has the values of the variables and the frequency count.

State	Test	Group/Test ID	Count
Diseased	Positive	1	3
Diseased	Negative	1	1
Healthy	Positive	1	0
Healthy	Negative	1	5
Diseased	Positive	2	24
Diseased	Negative	2	2
Healthy	Positive	2	2
Healthy	Negative	2	30

Frequency form dataset layout for 2 paired binary tests

Use a column for the true state variable (State), a column for each of the test indications (Test 1, Test 2) and a column for the number of cases (Frequency); each row has the values of the variables and the frequency count.

State	Test 1	Test 2	Count
Diseased	Positive	Positive	3
Diseased	Negative	Positive	1
Diseased	Positive	Negative	24
Diseased	Negative	Negative	2
Healthy	Positive	Positive	0
Healthy	Negative	Positive	5
Healthy	Positive	Negative	2
Healthy	Negative	Negative	30

Available in Analyse-it Editions
Method Validation edition
Ultimate edition