How we actually define, measure and analyse sedentary behaviour (SB) was the topic for discussion meeting on “Classification of Sedentary Behaviour: Towards a Taxonomy”.  Dr Sebastien Chastin facilitated the discussion.  Patient and expert alike were invited to the meeting, but unfortunately the public representation was low at this particular meeting.

A starting point:

 “Sedentary behaviour is not simply a lack of physical activity but is a cluster of individual behaviours where sitting or lying is the dominant mode of posture and energy expenditure is very low.” (DoH, 2011 cited in SIT, other definitions are also considered).

The meeting spurred discussion from physiologist, epidemiologists, computer engineers, health care professionals, psychologist, students and others.  We considered if we could gain expert consensus in the form of perhaps a hierarchical or faceted/networked method of defining older people’s behaviour.   The majority of people seem to feel that location/environment seems to be an appropriate starting point and location is a reasonably easy aspect. It is black and white – we are either indoors or outdoors or travelling, expanding on this we could be in a domestic, work, maybe leisure environment.  Interaction with others is another important aspect for us to understand if there is a social relationship to sedentary behaviour. Thus, when people are sedentary are they on their own, or with other and, if they are with others, are they engaging with them or perhaps not and just in a public place.  Should it be task driven? For example we have essential (eating, activities of daily living) and non-essential tasks (reading, tv watching, hobbies) in the day or should we be merely be describing the actual activity or asking the participant to state the activity and categorise it – TV watching, using a computer, (or combine with “screen use”), eating, driving, reading. Should sleep be included as SB? How important is posture? Relationship to energy expenditure?

If we really want to know about how we can begin to change behaviour, we need understand the context and motives for the behaviour, so we really need the participant to be telling us this. So, why are people sitting? resting, following a day of activity; boredom; education; social interaction; when are they doing it? for how long? the list goes on!

Defining the purpose of the measurement is crucial, so it a difficult task to consider how we can meet the needs of everyone in the measurement of SB.  Some feel there is not much point in consensus to such an extent, I suppose the looser the structure the more amenable it is for consensus across specialities. Can well put all this together in one assessment or is this unreasonable? Do we have to know everything or are some measurements more important. Objective? subjective? a bit of both? do we know enough at present to know what is important to measure?  One thing is for sure, the meeting raised more questions than it answered! And the discussion continues at: http://sedentarybehaviourclassification.net/

Who contributed to the discussion? Neville Owen, Charles Matthews, Sebastien Chastin, Paul Gardiner, Emmanuel Stamatakis, Mark Hamer, Jannique Van Uffelen, Phillipa Dall, Yu Ling Chen, Shilpa Dogra, Iuliana Hartescu, Barbara Jefferis, me and many others, I just didn’t catch everyone’s name, sorry if you are one of them (let me know).