An item bank is a set of questions that measures one particular construct, e.g. physical functioning or fatigue.

 

CAT is a method using a computer to efficiently (using only 3-7 questions) obtain a reliable estimate of a person’s health status (or an aspect of it). CAT is based on modern test theory (Item Response Theory (IRT)). In a CAT questions are asked based on given answers to previous questions. The content and number of questions are therefore different for each respondent (adaptive testing). However, each person gets a score that is comparable to scores of other persons (who might have completed other questions), because all questions are calibrated on the same scale by means of an IRT model. CAT therefore has the big advantage that less questions need to be completed to obtain a reliable score.

 

The item banks are generic, which means that they are suitable to be used in all kind of (patient) populations. There are separate item banks for adults and children. The item banks contain 6-124 items on the following domains and concepts

 

 

 

 

 

 

 

For more information on the domains and concepts see http://www.nihpromis.org/measures/domainframework