Factors which influence concordance among measurements obtained by different pulse oximeters currently used in some clinical situations

Abstract

Aims and objectives: To evaluate both concordance among those measurements obtained by three different pulse oximeters currently used by nursing professionals in hospital units and the factors which can influence this concordance. Background: Many models of wireless pulse oximeters in the present market do not offer possibility of calibration and, therefore, they do not ensure patients′ safety in daily clinical practice. Design: This is a descriptive and cross-sectional study. The sample of patients (140) was selected from such hospital units, and all of them had to fulfil inclusion and exclusion criteria for participation. Methods: The instruments used to carry out this research were a monitor (calibrated), two models of portable wireless pulse oximeters (used for 3 years by the nursing staff, without being calibrated), a tympanic thermometer and a weather meter. The concordance correlation coefficient (CCC) was used to establish the concordance, whereas the Landis-Koch criteria were used to interpret the results. Results: The concordance among the three devices was considered as “good” (CCC: 0.925 and 0.974 (95%)). The CCC (0.925) for saturation measures was regarded as “very good”/”almost perfect,” and the pulse measure was considered as “very good” CCC 0.974, providing in both cases a high level of concordance (CCC > 0.91). Conclusions: The overall concordance as regards pulse and oxygen saturation among the three pulse oximeters analysed is considered as “very good” according to the Landis-Koch criteria. Relevance to clinical practice: There exists a “very good” concordance among two wireless oximeters which have been used by the health staff for 3 years and which did not offer any possibility of calibration and one monitor which belongs to the healthcare institution. This aspect is of crucial importance in daily clinical practice, and it is also relevant to ensure patient's safety.