Data collection visits
We designed Project OPAL as a ‘descriptive’ study. We wanted to measure and understand participants’ normal behaviour. Participating usually involved three or four data collection visits, which usually happened at home. Visits tended to average about 1½ hours, and one or two members of the research team attended. The following descriptions outline the measurements and information we collected.
Visit 1
During the first visit, we:
- measured height and weight.
- conducted short physical function tests.
- asked an in-depth research questionnaire.
- delivered and explained an activity monitor and diary. The monitor is like a small, sophisticated pedometer, which objectively measures movement in a vertical plane, whilst worn around the waist. It's called an accelerometer.
Visit 2
The second visit was slightly shorter than the first. It took place about a week after the first visit to:
- collect the activity monitor and diary.
- finish the in-depth questionnaire.
- check if the participant could help with an additional 'sub-study.'
Sub-study visit(s)
We didn't need to see everyone for our extra sub-studies, which was either an individual interview or ‘GPS’ study. Extra thanks go to all participants who helped us out with them.
Visit 3 ("OPAL-Plus")
We aim to re-visit participants approximately three years after their second visit. This is to repeat activity monitoring, re-assess physical function and ask a few more questions. Please note that, if you're an OPAL participant, this is a little bit later than we first explained. If we haven't already been in touch, you might expect a call from us again quite soon!