Health comparison - commute on foot, by cycle, by train, and by car

[whole diary]

[grahame]

From the Hippocratic Post

Walk or cycle to work to reduce early death

People who walk, cycle and travel by train to work are at reduced risk of early death or illness compared with those who commute by car.

These are the findings of a study of over 300,000 commuters in England and Wales, by researchers from Imperial College London and the University of Cambridge.

The researchers say the findings suggest increased walking and cycling post-lockdown may reduce deaths from heart disease and cancer.

The study, published in The Lancet Planetary Health, used Census data to track the same people for up to 25 years, between 1991-2016.

It found that, compared with those who drove, those who cycled to work had a 20 per cent reduced rate of early death, 24 per cent reduced rate of death from cardiovascular disease (which includes heart attack and stroke) during the study period, a 16 per cent reduced rate of death from cancer, and an 11 per cent reduced rate of a cancer diagnosis.

Walking to work was associated with a 7 per cent reduced rate in cancer diagnosis, compared to driving. The team explain that associations between walking and other outcomes, such as rates of death from cancer and heart disease, were less certain. One potential reason for this is people who walk to work are, on average, in less affluent occupations than people who drive to work, and more likely to have underlying health conditions which could not be fully accounted for.

The paper also revealed that compared with those who drove to work, rail commuters had a 10 per cent reduced rate of early death, a 20 per cent reduced rate of death from cardiovascular disease, and a 12 per cent reduced rate of cancer diagnosis. This is likely due to them walking or cycling to transit points, although rail commuters also tend to be more affluent and less likely to have other underlying conditions, say the team.

[CyclingSid]

Full text paper at https://www.thelancet.com/journals/lanplh/article/PIIS2542-5196(20)30079-6/fulltext

This confirms various previous studies, which seem to have had little effect on government policy.

It shows, once again, the disparity between male and female cycling, and the difference between white and ethnic minority groups. The difference between graduate and non-graduate is hardly sufficient to warrant the recent diatribe from the London Taxi Drivers Association. Intrigued as to why they used Carstairs as a measure of deprivation as opposed to the Index of Multiple Deprivation. There are a variety of deprivation measures each of which give emphasis to different parameters. Have to find time to read it and find out.

[eightf48544]

They missed my favourite form of urban transport the on road trams.

Clean, quite, non poluting, can penartrate town centres, can be given priority at junctions and reduce traffic including buses (which don't seem to mentioned). Althoughreducing traffic is contentious

[stuving]

They missed my favourite form of urban transport the on road trams.

Clean, quite, non poluting, can penartrate town centres, can be given priority at junctions and reduce traffic including buses (which don't seem to mentioned). Althoughreducing traffic is contentious

The main study used data derived from censuses for 1991-2011, so the questions asked were census questions. There was a single choice for "public transport", and trams (and light rail) were listed as one mode within that only in 2001 and 2011. That's just one of those things about doing long-term research like this that you have to put up with - your choice of what to have asked people thirty years ago is a bit limited ...

[stuving]

They missed my favourite form of urban transport the on road trams.

Clean, quite, non poluting, can penartrate town centres, can be given priority at junctions and reduce traffic including buses (which don't seem to mentioned). Althoughreducing traffic is contentious

The main study used data derived from censuses for 1991-2011, so the questions asked were census questions. There was a single choice for "public transport", and trams (and light rail) were listed as one mode within that only in 2001 and 2011. That's just one of those things about doing long-term research like this that you have to put up with - your choice of what to have asked people thirty years ago is a bit limited ...

I misread that table, which is rather ambiguous. From the study itself, it's clear that the census did offer a choice of individual modes, and even a write-in option for "other". So it was the study that aggregated them by only using the top-level choice (vehicle/public transport/walk/cycle). They did look at bus and train separately, and report that the beneficial association with health outcomes was much stronger for train than bus travel to work.

No doubt the aggregation was needed to get enough numbers in every box - this kind of study has boxes for a lot of combinations of possible confounding factors with travel mode, and statistics always needs quite big numbers if it's to work properly.

All the results are associations - not causal links. They say they looked at reverse causality (i.e. did poorer health determine travel mode), but I can't see the results of that in the text. But they do say that all of their attempts to adjust for known factors thought to be causal - most of which are to do with deprivation in some sense - will leave some common factors still present. Obviously it's hard to say how big that is - one of those "what do you know about what you don't know about" questions.

And of course the "no time machines" rule still applies.

[Red Squirrel]

Sorry, I've been a bit slow to joining this debate. Just spotted another article on this topic, and I think it's worth quoting:

We followed people for around five years, counting the incidences of heart disease, cancers and death. Importantly, we adjusted for other health influences including sex, age, deprivation, ethnicity, smoking, body mass index, other types of physical activity, time spent sitting down and diet. Any potential differences in risk associated with road accidents is also accounted for in our analysis, while we excluded participants who had heart disease or cancer already.

We found that cycling to work was associated with a 41% lower risk of dying overall compared to commuting by car or public transport. Cycle commuters had a 52% lower risk of dying from heart disease and a 40% lower risk of dying from cancer. They also had 46% lower risk of developing heart disease and a 45% lower risk of developing cancer at all.

My emphasis.
Source: The Conversation