This document describes the cognitive tests. There are three collections of these data:
- A Baseline Cognitive Testing, for tests conducted up from 2008 until March 2015.
- The Pre-2020 Follow Up Cognitive Testing dataset that began in November 2015 and ended in March 2020.
- The Post-2020 Follow Up Cognitive Testing of follow-up that began post 2020.
This document provides a detailed description of the cognitive testing protocol.