Are the safety stats misleading ?

[mjr]

That has to be true. The average copper is not known as a diagnostician, so won't be able to record a serious injury.

They use a very simplistic method which is described in some document on gov.uk but IIRC boils down to serious meaning being taken to hospital or a few other visible injuries and all else being minor or killed.

Reg is correct that there are injury stats from hospitals, but I think they're not as widely used, partly because they're patchier. I've yet to see my local public health department use them at all.

 

[gaijintendo]

I think the confusion comes from the fact that the main database, STATS19, is administered by the police. However, the data in there comes from a variety of sources,

The police data in STATS19 provides data on things like the types of vehicles involved, what roads they were on and the consequent casualties.

The details around the types of injuries treated and clinical outcomes come from the NHS data which is fed into STATS19.

Just a health warning for any NHS reporting...

That data might be gathered by audit (people reporting particular events, Which is generally of good quality but can be under reported), or it can be gleaned from operational data.

Operational data doesn't exist to give accurate statistics, but merely move people from ward to ward, get them their meds, and operations. Those too are subject to errors, but more endemic than an audit. If you are searching on a term, it might not be labelled correctly or systematically one hospital might use a different terminology. It could contain coded items, free text... any number of inaccuracies.

Given the drive for insights, banks of humans review data to bend it to reality. With a growing backlog, and little clarity, things often don't even get a bit closer.

Then the assumption is, the data is handled, extracted, cropped by appropriate cohort with all the correct kind of joins then reassembled in a national dataset... with extreme professionalism and accuracy at each step?

So, you know...NHS data... It's as good a guess as anyone could make.

 

[mjr]

I think the confusion comes from the fact that the main database, STATS19, is administered by the police. However, the data in there comes from a variety of sources, [...] The details around the types of injuries treated and clinical outcomes come from the NHS data which is fed into STATS19.

I asked the county analyst responsible "is the data only from the police, or does hospital data get into it?" and got this reply: "CRASH data, as was the case with STATS19, comes exclusively from the Police. Hospitals have their own system for recording admissions known as HES (Hospital Episode Statistics) which is not linked to CRASH. Efforts have been made in the past to connect the two data sets, but this has proven to be almost impossible due to NHS data protection policies."

Maybe it happens in some parts of the country, but not in Norfolk and almost certainly not in Suffolk (which shares a roads policing unit).

 

[Mr Bunbury]

So what do we know:-

• In the uk about 100-120 cyclists per year are killed on uk roads
• There is a formula that calculates 1 cycling death per 2 million miles travelled (I think)

Then there is the alarming figure of serious injuries while cycling ...

It's alarming ... and completely wrong. The government statistics given below show 26 deaths per billion cyclist kilometres. That works out as one cyclist death per 24 million miles. You're out by a factor of twelve.

Passenger casualty rates for different modes of travel - GOV.UK

 

[kingrollo]

It's alarming ... and completely wrong. The government statistics given below show 26 deaths per billion cyclist kilometres. That works out as one cyclist death per 24 million miles. You're out by a factor of twelve.

Passenger casualty rates for different modes of travel - GOV.UK

It wasn't deaths that I referred to as alarming - its the increase in serious injuries, which multiple reports show are rising

 

[jarlrmai]

I asked the county analyst responsible "is the data only from the police, or does hospital data get into it?" and got this reply: "CRASH data, as was the case with STATS19, comes exclusively from the Police. Hospitals have their own system for recording admissions known as HES (Hospital Episode Statistics) which is not linked to CRASH. Efforts have been made in the past to connect the two data sets, but this has proven to be almost impossible due to NHS data protection policies."

Maybe it happens in some parts of the country, but not in Norfolk and almost certainly not in Suffolk (which shares a roads policing unit).

There's anecdote on these forums about a guy who bashed his head on a pedal while fixing his bike in the shed, the nurse asked if he was wearing a helmet, so that might have been recorded as a cycling accident.

 

[srw]

It wasn't deaths that I referred to as alarming - its the increase in serious injuries, which multiple reports show are rising

Apart from the one you're replying to...

Sorry to be a pedant, but that doesn't show serious injuries rising. It shows serious injuries as pretty static from 2006 - 2010 and again pretty static from 2011 - 2015.

There are any number of things that could cause this, but top of my list would be a one-off change in methodology of collecting or collating the stats in 2011.

Two other things to bear in mind. First, "serious injuries" in the technical sense aren't actually necessarily "serious" in the colloquial sense. When Mrs W was knocked off her bike and admitted to hospital because she'd been kept waiting in A&E for 4 hours - the hospital didn't want to bugger up their A&E targets - that counted as a "serious injury" even though she walked out of hospital the same day and was pain-free within a couple of weeks. Second, the denominator of the rate - the distance cycled - is incredibly difficult to measure, and the ONS have said that it's possibly unreliable - under-reporting quite a lot.

Oh, and of course 650 per billion kilometres is tiny. Absolutely minute. It's one per 1.5 million kilometres. Steve Abraham is trying to ride 120,000 km in one year, at a pace of something over 300km per day. If he did that every year it would still take him 12.5 years to ride 1.5 million km.

 

[kingrollo]

Apart from the one you're replying to...
View attachment 394643

Sorry to be a pedant, but that doesn't show serious injuries rising. It shows serious injuries as pretty static from 2006 - 2010 and again pretty static from 2011 - 2015.

There are any number of things that could cause this, but top of my list would be a one-off change in methodology of collecting or collating the stats in 2011.

Two other things to bear in mind. First, "serious injuries" in the technical sense aren't actually necessarily "serious" in the colloquial sense. When Mrs W was knocked off her bike and admitted to hospital because she'd been kept waiting in A&E for 4 hours - the hospital didn't want to bugger up their A&E targets - that counted as a "serious injury" even though she walked out of hospital the same day and was pain-free within a couple of weeks. Second, the denominator of the rate - the distance cycled - is incredibly difficult to measure, and the ONS have said that it's possibly unreliable - under-reporting quite a lot.

Oh, and of course 650 per billion kilometres is tiny. Absolutely minute. It's one per 1.5 million kilometres. Steve Abraham is trying to ride 120,000 km in one year, at a pace of something over 300km per day. If he did that every year it would still take him 12.5 years to ride 1.5 million km.

Yes I think life changing injuries would be a better measure.

 

[byegad]

There's anecdote on these forums about a guy who bashed his head on a pedal while fixing his bike in the shed, the nurse asked if he was wearing a helmet, so that might have been recorded as a cycling accident.

It was I and yes they recorded it as a cycling accident. Much to my annoyance!

 

[MontyVeda]

It was I and yes they recorded it as a cycling accident. Much to my annoyance!

I'd be annoyed too... but the mileage from the anecdote... priceless

[edited for grammar]

 

[byegad]

I'd annoyed too... but the mileage from the anecdote... priceless

I never hold a grudge too long, twenty years after I'm safely dead will be enough!

 

[mjr]

Continuing from elsewhere as instructed by a mod:

I don't understand the logic of "per time" for a journey, else you could make the journey "safer" simply by driving faster to reduce the time exposed. This makes no sense whatsoever.

Clearly, there's some sort of implied assumption that people won't put themselves in danger with their speed, but for a reasonably prudent traveller, it might well be safer to take the route where you can travel faster if that means being exposed to dangerous motorists (who outnumber even you driving, no matter how safe your own driving) for less time... but there's probably also some threshold speed for each mode of transport, above which safety decreases faster than the time you'd save.

However, I think most cyclists are travelling almost as fast as they feel is safe already, so speeding them up much without route improvements would cross that threshold and decrease safety - but it still feels like it's relevant for comparing a reasonably prudent cyclist with a reasonably prudent motorist to compare a 20 minute cycle with a 20 minute drive, or to compare "per trip stage" figures.

Of all the comparisons we could make, per mile may be the second worst (after absolute numbers) for cycling and walking. In urban areas, the distance travelled may be similar, but per mile statistics are probably skewed by a fairly small number of extremely long distance journeys.

 

[User10119]

Similarly, copied from elsewhere....
[QUOTE 5252288, member: 45"]If you're cycling for an hour on the roads you're exposed to the risk from cars for twice the amount of time as if you were cycling for 30 minutes, all other things being equal. How safely you were cycling only has an effect if it was different in the two scenarios. We're not talking about the same distance in both.[/QUOTE]
(my bold)
@Profpointy - is someone driving on the motorway for an hour at an average 70mph as dangerous/in as much danger as someone driving for 30 minutes at an average 140mph, for each of those minutes? They've covered the same distance, but not in the same way.

If someone were to set off from my house to drive to my mam's they'd be there in about 20 minutes. If I set off to cycle the same route (note, I've only ever attempted said route once on a bike and I gave up and headed for the lanes about 3/4s of the way there because enough people had finished their Christmas lunch for the traffic conditions to be getting pretty unfriendly by that point) it would take me, I'd estimate, about an hour and a half*. I have friends who could easily do the same journey on their bikes in half the time. Would they be exposed to the same risk as me over that distance?

I guess neither metric is perfect. But someone setting off to do 70 miles in a car would probably expect the journey to take somewhere between an hour and an hour and a half, depending on the nature of the route and how strictly they observe speed limits, whereas most people (leaving out the well'ard audax types that can keep up imperial evens all day) setting off to a 70 mile bike ride would be looking on it as a nice day ride. Or a Mission Impossible, currently, for those such as me who have lost all their fitness and gained too much lard In that time they would, just to think of the most obvious difference, be likely to have far more interactions with other road users.


*although in my fitter days I did once do the slightly longer, much nicer, route in about an hour and 15 minutes - ah, happy halcyon days