The Variables page allows you to define inputs, intermediate calculations, and survival distributions in your model. To access the Variables page, click on in the navigation sidebar on the left-hand side of your screen. The variables page is divided into two tabs – one for parameters, and the other for survival distributions.
Parameters
Parameters is where you define input variables and intermediate calculations, including parameters such as utility values, costs, probabilities, constants, flags, or any parameters other than survival distribution objects. The Parameters page is set up in tabular format, with each row representing a parameter and columns as follows:
Column |
Description |
Name |
Name of a variable. Each name must be unique, start with a letter, and may only contain letters, numbers, and underscores. Variable names may be no longer than 20 characters in total. |
Description |
Label providing a description of the parameter. Labels have no restrictions on the types of characters used, and can be up to 30 characters long. |
Category |
Category to which a parameter belongs (eg, costs, utilities). |
Formula |
A formula that specifies the value that a parameter takes on, which can be a numeric constant. To define a string constant, put the value in quotes. |
Source |
A source citation for your estimate of the value of a parameter. If a URL is entered, it will be displayed as a hyperlink. |
Survival Distributions
The Survival Distributions tab can be used to define special variables that represent survival distributions defined using hēRo3’s survival modeling functionality. The Survival Distributions tab is defined in tabular format, with each row representing a variable that refers to a given survival distribution, with columns as follows:
Column |
Description |
Name |
Name of the survival distribution variable. Names must be unique, start with a letter and may only contain letters, numbers, and underscores. Names are limited to 20 characters in total length. |
Description |
Label that provides a description of the variable. Labels have no restrictions on the types of characters used and can be up to 30 characters long. |
Formula |
An R expression that defines a survival distribution. This expression should use the built-in hēRo3 functions for defining survival distributions. |
Source |
Source for a parameter value. If a URL is entered, it will be displayed as a hyperlink. |