Thursday, November 29, 2012

Bed Alarms in Hospitalized Patients: Useless

Many older patients fall in the hospital and these falls often lead to injury.  Hospitals are under a lot of pressure to reduce falls.   Generally, these falls happen when patients transfer such as when an older person tries to get out of bed or get up from a chair.   While hospitalized, many patients are weak, dizzy, or confused, and they can be at risk of falling when ambulating without assistance.

To reduce this risk, bed alarms have become ubiquitous at hospitals throughout the US.  When a patient is deemed to be at high risk of falling, weight sensitive pads are applied to the bed, chair, or commode.   When a patient tries to get up, an alarm sounds in the room and at the nursing station.  The alarm reminds the patient to wait for assistance, and alerts nursing staff to assist the patient.

Remarkably, these alarms have become widely used with virtually no evidence that they actually reduce falls, let alone any studies that examine the adverse consequences of restricting mobility.  I am not aware of any studies that ask patients how they feel about being attached to these devices. In general, hospitalized older patients are not even asked permission to apply these devices.

This context makes a study by Geriatrician Ron Shorr at the University of Florida particularly remarkable.  In a well done study, Shorr provides compelling evidence that these bed alarms fail miserably at their core purpose of preventing falls in high risk hospitalized patients.

To test the usefulness of bed alarms, they did the following.  They took 16 medical surgical units at a Memphis teaching hospital and randomly assigned 8 units to a bed alarm intervention and 8 units to usual care.  On the intervention unit, the staff received extensive training on the use of the bed alarms and was strongly encouraged to use the alarms on patients felt to be at high risk of falling.  Shorr and colleagues compared the rate of falling and fall injury before and after the bed alarm intervention was introduced on both the intervention and the control units.  The findings were as follows:


  • On the bed alarm units, there were 5.76 falls per 1000 patient days. About 1/4 resulted in injury
  • On the usual care unit, there were 4.56 falls per 1000 patient days.  About 1/4 resulted in injury
  • The trend towards higher fall rates on the intervention units was not statistically significant, so the study does not show that bed alarms lead to more falls.  But this trend almost certainly rules out any meaningful chance that this bed alarm system, as implemented in this study, can reduce the risk of falls.
This study raises serious questions about the growing use of bed alarms in US hospitals.  As the authors note, these systems are not cheap.  

Maybe we need to rethink hospital fall prevention, and focus on more human and less technical solutions.  Bed alarms have the potential to be activity restricting.  This activity restriction can actually increase the risk of hospital acquired disabilities that are very common in hospitalized elders.  Frail older patients need to be encouraged to get out of bed and ambulate.   Solutions aimed at getting high risk patients the assistance they need when they need it are likely to be more effective than bed alarms.  Also, we need to learn how to make environmental modifications in our hospitals that make it safer when patients actually do fall so that these falls are less likely to cause injury.  

So, add bed alarms to the long list of medical interventions that have been widely used despite no evidence that they actually work.  


by: Ken Covinsky

12 comments:

Jordan said...

One alternative and one question come to mind:

Alternative: Why not change the floor in a hospital room to something softer, like what is used on new playgrounds? At least this will cushion a fall should one occur. I think it's also easier to walk on, thus further reducing the risk of falling.

Question: How did these bed alarms work? Seems like they might be a good idea poorly executed. Perhaps a pressure monitor on the bottom of the foot? Seems monitoring when a patient is rising or ambulatory is a reasonable complement to the other signs we monitor.

Anonymous said...

"The trend towards higher fall rates on the intervention units was not statistically significant".
Could this possibly be related to all of the potential confounders in this study?? Does not sound like a very well planned research study.

Also,how are the fall risk patients identified?
The nurse was expected to "feel" which patients were high risk for falling and initiate an alarm. Seriously??? Personally, I am confident my "feelings" concerning whether a patient is at risk to fall is far less of a significant indication than using a valid risk assessment tool.

As far as being attached to a device, that is inaccurate with the bed alarms I have seen. Most of these devices have a pressure sensitive pad that is placed under the patient. So actually, mobility is not restricted as this article claims. Bed alarms are appropriate when utilized correctly in adult acute care facilities, however, this is assuming that a valid fall risk assessment tool is used to identify the correct patient for use. Bed alarms certainly are a big improvement from use of restraints!

Manasa Edward said...
This comment has been removed by the author.
Eric Widera said...

If I heard an alarm coming from my bed, my natural instinct would be to get father away from the bed, not to lie back down.

Manasa Edward said...

Having a alarm is better .. provided I know that there is an alarm and that I am supposed to stop moving when it rings ..

Med Procidures

palliate said...

Another possible explanation for bed alarms failing to prevent falls and injuries.... When bed alarms are in place, might staff be less vigilant in physically checking in on the patient. In other words, it's not that bed alarms fail, it's that you optimally need both bed alarms and vigilant nursing care and when the former is present, the latter is decreased.

Anne Nonomous said...

Could you post a hyperlink to the actual published article you are discussing. Your summary leads to multiple questions that would be answered by reading the article

Alex Smith said...

Hi Anne Nonomous (ha!) Click on the word "study" in the post to see the article.

Alex Smith said...

Seems like bed alarms are a good candidate for some groups Choosing Wisely campaign (internal medicine, geriatrics, or hospital medicine).

Anonymous said...

My mother said the chair and bed alarms in the nursing home were a like being in a psychological prison.They certainly responded faster than just putting on the call light.

Damaris Mullins said...

Somehow, in my experience the bed alarms in the hospitals are very useful. One time when nobody was inside the room of my parents and something happened to them, the bed alarms were just the only thing that helped them.

Kathryn Siebert said...

As far as being attached to a device, that is inaccurate with the bed alarms I have seen. Most of these devices have a pressure sensitive pad that is placed under the patient. So actually, mobility is not restricted as this article claims. Bed alarms are appropriate when utilized correctly in adult acute care facilities, however, this is assuming that a valid fall risk assessment tool is used to identify the correct patient for use. Bed alarms certainly are a big improvement from use of restraints!