Patients in intensive care units (ICUs) who are shorter in height are more likely to die in hospital than taller ones who have much better survival rates, finds a new study.

The study showed that the average-height man's odds of dying are just over 22 per cent, but that death risk increases by around 30 per cent for the very shortest. In addition, women see their death rates jump from 17.1 to 24.1 per cent if they are shorter, as per the study published in the journal Intensive Care Medicine.

The reason shorter people may be at a higher risk of death could be because a lot of intensive care equipment is set up for average-sized male patients. It could be that shorter people are given too large a dose of medication, more than required, such as sedatives resulting in sleepiness, which ultimately causes them to stop breathing. 

In addition, wrong-sized breathing tube could cause damage to the vocal cords in shorter people, Daily Mail reported. A ventilator not adjusted for someone's height can damage their lungs as they are forced to take larger breaths than necessary, results showed.

"There is not a single thing which could explain this increase in mortality in shorter people admitted to intensive care units," said Hannah Wunsch, researcher from the Sunnybrook Hospital in Canada. "The message from this research is for doctors to be more aware of people's height."

"We know doctors do not always measure people's heights but equipment settings should often take this into account. The small differences relevant to how tall someone is can add up," noted Wunsch. For the study, researchers included 400,000 patients at 210 intensive care units.