RevMan can calculate the sensitivity and specificity of a test from each study, plot the estimates in ROC space and draw a summary ROC (SROC) curve for descriptive and exploratory purposes.
Before you can begin analyzing your data, you must have added the studies to the Included Studies section.
You can then set up data tables for each test that you want to include in your review by creating tests and entering test data (I.e. the number of true positives, false positives, false negative, and true negatives) for the studies.
Tip! If you define your covariates before you begin entering data, the covariates can be entered simultaneously with the rest of the data, so that you will not need to go back and check the data in studies later.
Once your data tables have been set up you can begin Entering data.
To analyze the data, you must set up analyses, see Analysis graphs in DTA reviews.
Set up tests
- Open the Review Criteria section in the left-hand navigation and navigate to the Test tab to add tests that you want to report data for.
- Click Add test and enter a test name, full name (optional) and description (optional).
- You can move tests up or down or delete them.
Note: You must have added studies to the Included Studies section before you can begin entering test data.
After you have set up the tests, you can enter the data of each study in the cells. See Entering data.
You can add covariates if you would like to see how the results differ between subgroups of studies or if you want to include these covariates in your meta-regression analyses (see Analysis graphs in DTA reviews). It may be wise to define your covariates before you start entering data. The covariates can then be entered simultaneously with the rest of the data (instead of going back and adding covariate data for the studies afterwards).
To add a covariate:
- Open the Review Criteria section and navigate to Covariates.
- Click Add covariate.
- Enter the name of the covariate and a more detailed description.
- Select whether you want to enter the data for this covariate at the study or test level.
- Choose data type.
a. For continuous covariates, you may enter a default value.
b. For categorical covariates, you must define the different categories. Click Add to create a category. When all categories have been created, use the pull-down list to specify the default category. If you would like to be able to show subgroups on the SROC plot, you should choose the categorical data.
Note: Although you may want to explore the effect of certain methodological quality items (signalling questions or domain judgements) and would like to add these as covariates, these need not to be entered under this heading. The methodological quality items are already under the Characteristics of Included Studies.
Entering test data
To enter data:
- Go to Studies > Included studies > Click Edit for the study that you want to add test data for.
- Navigate to the Test data tab.
- Click Add test data row.
- Select the relevant test and enter the data.
- Repeat for each test data row.
Tip! If you have all your test data in a tabular format with columns in the same order as in RevMan, you can copy-paste a whole table of values. When you have finished inputting the data for each study, RevMan automatically calculates the values of sensitivity and specificity and plots the forest plots of sensitivity and specificity.
If you only know some of the values of the 2 by 2 tables for an included study, you can use the calculator tool to obtain the 2 by 2 Table from other parameters, such as sensitivity and specificity, prevalence of the target condition or the number of people with the target condition.
To calculate data:
- Go to Studies > Included studies > Click Edit on the study you want to add test data for.
- Navigate to the Test tab.
- Access the calculator by clicking the Action menu for the test data row. Any study data already entered is used in the corresponding fields.
- Input the data you have. If the number you enter is valid, the background in the cell is green. If there is an error in the data, the field is marked red. For example, you should enter sensitivity and specificity as proportions and not as percentages. So, for example, 0.74 instead of 74 or 74%. If you enter 74, the cell turns red. Tip! You can use Tab key to move to the next field.
- Click Update data table to save the calculated data. The calculator input data will be saved so that you can access it again later.