Time to Discovery After a Fall: The Evidence, With Its Denominators

The 1981 finding, and the citation that has been wrong for years

Search for "long lie mortality" and you will find, on hundreds of pages, the claim that roughly half of older people who lie on the floor for more than an hour after a fall die within six months. The claim is real. The citation attached to it very often is not.

The figure comes from Wild, Nayak and Isaacs, "How dangerous are falls in old people at home?", published in the British Medical Journal in 1981 (PMID 6779979). Its abstract states, in these words, that "of those who lay on the floor for more than one hour, half died within six months of the fall". The study followed 125 people aged 65 and over who fell in their own homes, identified through six general practices. Twenty of them lay on the floor for more than an hour. Three fractured a femur, fifteen had other fractures, and most of the rest suffered only trivial injuries.

The figure is frequently cited instead to PMID 19015185. That is Fleming and Brayne's 2008 BMJ study of people over 90, and it contains no six-month mortality figure at all. It is an important paper — it is the source for several of the numbers further down this page — but it is not the source for this one. This site published the wrong attribution for a period and has corrected it.

Two caveats belong with the figure, and they belong in the same breath as the figure itself. The first is the denominator: twenty people. This is a small subgroup within a small study. The second is what the same paper found about the whole cohort — one quarter of all 125 fallers died within a year, five times the rate in an age- and sex-matched control group. That larger finding rests on a larger denominator and points the same way: a fall at home in old age is a marker of serious underlying ill health, and the long lie sits on top of that rather than replacing it.

How often the long lie happens

The best modern prevalence data on lying on the floor after a fall comes from the Cambridge City over-75s Cohort. Researchers followed 110 people aged over 90 — 90 women and 20 men — for a year, using fall calendars, phone calls and visits rather than relying on recall.

Of the 265 falls reported, 82% happened when the person was alone and 54% left them found on the floor. Sixty per cent of the participants fell at all; of those 66 fallers, 80% were unable to get up without help after at least one fall, and 30% had lain on the floor for an hour or more.

Those are strikingly high proportions, and the reason is the cohort: everyone in it was over 90. This is the oldest-old, not older people generally, and the numbers should be quoted with that attached. What the study established beyond its own age band is the mechanism — that inability to rise, not the fall, is what converts a survivable event into a long lie, and that lying on the floor for a long time was strongly associated with serious injury, hospital admission, and subsequent moves into long-term care.

Time down, not the fall, drives the outcome

The strongest anchor for the response-gap argument is not a falls study at all. In 1996, researchers published a population-based study in the New England Journal of Medicine of people found in their own homes either helpless or dead. Over twelve weeks, San Francisco paramedics identified 387 such events involving 367 people.

The median age was 73 and 51% were women. In 23% of cases the person was found already dead; a further 5% died in hospital, giving total mortality of 28%. Of those found alive, 62% were admitted to hospital, the average stay was eight days, and 52% of those admitted needed intensive care.

The finding that matters most is this one: total mortality was 67% for people estimated to have been helpless for more than 72 hours, against 12% for those found within an hour. Same city, same paramedics, same twelve weeks — the variable is time.

The study's own conclusion is worth quoting because it is more sober than most of what is written about it: "For elderly people who live alone, becoming incapacitated and unable to get help is a common event, which usually marks the end of their ability to live independently." Of the survivors, 62% were unable to return to living independently.

This is an observational study, and the direction of causation is not settled by it: someone who has been down for three days may have been down that long partly because whatever happened to them was more severe. But the association is very large, it is consistent with the 1981 mortality finding, and it is the closest thing this field has to a dose-response curve for delay.

What a long lie actually does to the body

A "long lie" is defined clinically as being unable to get up for sixty minutes or more after a fall. That threshold is a clinical convention rather than a biological cliff-edge, and it is worth distinguishing from the much shorter windows that automatic fall-detection software uses to decide whether someone is still on the floor — those are surrogate measures for a detector, not the clinical definition.

The complications associated with a prolonged period on the floor are well described in the clinical literature: dehydration; pressure injuries where body weight compresses skin against a hard surface; rhabdomyolysis, the breakdown of muscle tissue, which can cause acute kidney injury; hypothermia, particularly on tiled or uncarpeted floors; and pneumonia. These are the mechanisms by which a fall that did not itself cause a serious injury can still end in a hospital admission or a death.

It is also why the outcome measures in the studies above are not only mortality. Fleming and Brayne found that time on the floor was strongly associated with serious injury, hospital admission and moves into long-term care. Gurley's cohort lost their independence far more often than they lost their lives. For a lot of people, the thing at stake in the discovery window is not survival — it is whether they go home afterwards.

The uncomfortable finding: call alarms were available and not used

The Fleming and Brayne study includes a result that anyone selling a safety product should have to sit with. Call alarms were widely available among the participants — and in most cases of falls that led to lying on the floor for a long time, they were not used.

The researchers' interviews with older people and their carers surfaced why: perceptions that the alarm was irrelevant to them, concerns about what wearing one meant for their independence, and straightforward practical difficulties — the pendant on the bedside table, the one taken off in the shower, the button that requires a press from a person who has just been knocked unconscious or cannot reach it.

That is a finding about human behaviour, not about technology, and no amount of engineering makes it go away. It is the reason we are sceptical of any safety claim that depends on the person in trouble taking an action at the moment of trouble. A daily check-in inverts that dependency: the action is taken when you are well, in a routine you already have, and the alert is what happens when the action is absent. It is a weaker signal than a pressed button, and it arrives later than a pressed button would have — but it does not require anything of you at the worst possible moment.

What actually shortens the discovery window

Nothing here is an argument that a phone app is the best answer to this problem. For a lot of people it is not. A housemate is better. A neighbour with a key who looks in every morning is better. A community alarm service with a responder attached is better, if it is used. Japan's mimamori services and Singapore's HDB Elderly Monitoring System are better within the homes they cover.

What those options have in common is that they are not universally available, and that the strongest of them are tied to a specific address. What a check-in offers is not superiority; it is coverage — it works from the phone you already carry, in any room, at any address, at no cost for the check-in itself.

The honest description of the benefit is bounded by the mechanism. A daily check-in compresses the worst case from indefinite to about a day. It does not get you to the one-hour band in Gurley's data. If your risk profile means an hour matters, you need something that responds in an hour — and that is a conversation to have with a clinician and a local service, not with a website.

I'm Alive is a daily check-in app. You confirm you're okay once a day; if you don't, the people you chose are told, with your location. The daily check-in is free (Try It, $0) and works on iPhone and Android. Automatic alerts to your contacts start on Protect Me ($29.99/year), with location on the move on Protect Me On The Move ($39.99/year); there is a one-time Stay Connected lifetime upgrade at $4.99. Check-first phone fall detection is available on iPhone only (app v2.3.1), on Protect Me and above, and stays off until you switch it on — and it runs only while the app is open, so it is not background monitoring and should not be relied on as though it were. There is no Android fall detection, and we do not use Apple Watch fall detection. When it does fire, it checks with you first and then alerts your own trusted contacts. It never calls emergency services. It is best-effort, and it is not a medical device.

Nothing on this page is medical advice. If you are worried about your own or someone else's fall risk, that is a conversation for a clinician, who can look at medication, blood pressure, vision, balance and strength together. If someone has fallen and may be hurt, call your local emergency number.