Validation of Dutch Obstetric Telephone Triage System: A Prospective Validation Study

A triage system that prioritizes care according to medical urgency has a favorable effect on safety and efficiency of emergency care. The Dutch obstetric telephone triage system is comparable to physical triage systems. It consists of five urgency levels: resuscitation and life threatening (U1), emergency (U2), urgent (U3), non-urgent (U4) and self-care advice (U5). The purpose of this study was to determine the diagnostic and external validity of the Dutch obstetric telephone triage system in obstetric emergency care.

The validity of the Dutch obstetric telephone triage system was studied in a prospective observational study in four hospitals. Diagnostic validity of usual care was determined by comparing the assigned urgency level of the Dutch obstetric telephone triage system with a reference standard. This reference standard was obtained by face-to-face clinical assessment in hospital following telephone triage. Clinical follow-up after assessment was also recorded. For statistical analyses, urgency levels were dichotomized into high urgency (U1, U2) and intermediate urgency (U3, U4). Self-care advice (U5) could not be studied because these patients were not referred to hospital.

In total, 983 cases (U1-U4) across the four hospitals were included, 625 (64%) cases were categorized as high urgency and 358 (36%) as intermediate urgency. The Dutch obstetric telephone triage system's urgency level agreed with the reference standard in 53% (n=525; 95% CI 50-57%). According to the reference standard the Dutch obstetric telephone triage system had undertriage in 16% (n=160) and overtriage in 30% (n=298) of the cases. Sensitivity for high urgency was 76% (95% CI 72-80), specificity 49% (95% CI 44-53). Positive predictive value and negative predictive value were 60% (95% CI 56-63) and 67% (95% CI 62-72), respectively. After clinical assessment, urgent care was needed in 8.7% (n=31) of the intermediate-urgency cases, none of these cases were life threatening situations.

DOTTS shows an acceptable diagnostic validity with room for improvement.