Respiratory rate routinely inaccurate

In this single center study of ~200 ED patients, respiratory rate was measured by 3 modalities: usual criteria (counting for 15 seconds and multiplying by 4), an electronic harness sensor, or gold standard (counting for 60 seconds). The usual criteria had a sensitivity and specificity of 23% and 99% for tachypnea, while the harness was 91% and 97% respectively. Usual methods of detecting tachypnea will miss a significant majority of patients and should not be relied upon (abstract).