Eye tracking at the ICU- global market- REDO
In the U.S., 5.7 million patients are admitted to the ICU each year, and that figure is approximately 142 million worldwide. Of those patients, only around 4% are potential candidates for eye tracking, based on a number of factors that disqualify patients from this option, such as the prevalence of delirium in ICU patients. You'll find a deep dive of my research and triangulations below.
In the U.S., approximately 5.7 million patients are admitted to the ICU annually. Of those, 20-30% are on mechanical ventilation during their stay, which is the group most likely to use and benefit from eye tracking devices. However, not all patients on mechanical ventilation would be eligible for eye tracking. For example, if they are only on ventilation for a short period of time, eye tracking would not apply, since it does require some training to be useful. In addition, it would not be beneficial if the patient had severe visual impairment. Therefore, if 20-30% of patients are on ventilation, we will use the lower figure of 20% based on the assumption that not all of the patients will qualify.
So, if 20% of ICU patients are on ventilation and not disqualified from eye tracking for some other reason, that's 1.14 million of the total 5.7 million patients in the ICU. Another major factor that can disqualify patients from eye tracking, however, is if they are cognitively impaired and therefore unable to learn and use this skill. What I learned during my research is that being on mechanical ventilation in the ICU is actually a significant risk factor for cognitive impairment in the form of delirium. In fact, 80% of mechanical ventilation patients in the ICU experience delirium, which would disqualify those patients from being good candidates for eye tracking. So, if 80% of the 1.14 million mechanical ventilation patients are disqualified, that leaves 228,000 patients in the U.S (20% of 1.14 million).
I couldn't find a solid figure for the number of ICU patients globally, despite extensive searching. However, I found enough data to triangulate an estimate by scaling up the U.S. data. In 2005 (the most recent data available from the World Bank), there were 2.9 hopsital beds per 1,000 people in the world, and 3.2 per 1,000 people in the U.S. If we assume those ratios are still roughly true, we can estimate the total number of hospital beds:
Worldwide: population of 7.6 billion / 1,000 = 7.6 million
7.6 million x 2.9 = 22.04 million hospital beds
U.S.: population of 323 million / 1,000 = 323,000
323,000 x 3.2 = 1,033,600 hospital beds
Now that we know the total number of hospital beds, we can determine the ratio for the U.S. to the rest of the world:
1,033,600 / 22.04 million = 0.04 (4%)
So, the U.S. accounts for 4% of the world's hospital beds. If we assume that ratio applies at least roughly to the number of ICU patients as well, then we can estimate the number of patients worldwide:
(5.7 million ICU patients (U.S.) x 100) / 4 = 142.5 million
In other words, 5.7 million is 4% of 142.5 million, so that is roughly the number of ICU patients worldwide based on our ratio.
Now, we can use the same method of triangulation as above to estimate the share of these patients that are potential candidates for eye tracking: 20% are on mechanical ventilation, which is 28.5 million (142.5 million x 0.2). Of those, 20% are not disqualified by delirium, so that's 5.7 million (28.5 million x 0.2).
To wrap up, there are 5.7 million ICU patients in the U.S., and an estimated 142.5 million worldwide. Of those, an estimated 228,000 are potential candidates for eye tracking in the U.S., and 5.7 million worldwide.