There is only limited research relating to monitoring respiratory rate, and these studies focused on issues such as the inaccuracy of respiratory rate measurement and respiratory rate as a marker for respiratory dysfunction.
Inaccuracies in respiratory measurement have been reported in the literature. One study compared respiratory rate counted using a 15 second count period, to a full minute, and found significant differences in the rates. Respiratory rates measurement in children under five years, for a 30 second or 60 second period, suggesting the 60 seconds resulted in the least variability.
Another study found that rapid respiratory rates in babies, counted using a stethoscope, were 20% to 50% higher than those counted from beside the cot without the aid of the stethoscope.
The value of respiratory rate as an indica- tor of potential respiratory dysfunction has been investigated but findings suggest it is of limited value. One study found that only 33% of people presenting to an emergency department with a oxygen saturation below 90% had an increased respiratory rate.
An evaluation of respiratory rate for the differentiation of the severity of illness in babies under 6 months found it not to be very useful. Approximately half of the babies had a respiratory rate above 50 breaths per minute, thereby questioning the value of having a "cut-off" at 50 breaths per minute as the indicator of serious respiratory illness. It has also been reported that factors such as crying, sleeping, agitation and age have a significant influence on the respiratory rate. As a result of these and similar studies the value of respiratory rate as an indicator of serious illness is limited.