Capillary refill time (CRT) is a clinical test used to evaluate the circulatory status of patients, and there are various methods to assess CRT. Conventional clinical research often demands large numbers of patients, making it costly, labor-intensive and time consuming. We studied the interobserver agreement on CRT in a nationwide study using a novel methodology of research called ‘Flash Mob Research’ (FMR).
Physicians in the Netherlands were recruited by word-of-mouth, conventional media and social media to participate in a nationwide, single-day, “nine-to-five”, multi-center, cross-sectional, observational study to evaluate CRT. Patients 18 years and older presenting to the emergency department or hospitalized were eligible for inclusion. CRT was measured independently by two investigators at the sternum and distal phalanx after application of pressure for 5 (5s) and 15 seconds (15s).
On October 29th 2014, 458 investigators in 38 Dutch hospitals enrolled 1.734 patients. The mean CRT measured at the distal phalanx were 2.3 seconds (5s, SD1.1) and 2.4 seconds (15s, SD1.3). The mean CRT measured at the sternum were 2.6 seconds (5s, SD1.1) and 2.7 seconds (15s, SD1.1). Interobserver agreement was higher for the distal phalanx (κ-value 0.40) than for the sternum (κ-value 0.30).
Interobserver agreement on CRT is at best moderate. CRT measured at the distal phalanx yielded higher interobserver agreement compared to sternal CRT. FMR proved a valuable instrument to investigate a relative simple clinical question in an inexpensive, quick and reliable manner.