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

Figures & data

Table 1 Characteristics of Study Population and Presenting Symptoms

Hospital, Number of Patients Triaged = n, (%)*	Hospital A n=624 (63)	Hospital B n=193 (19)	Hospital C n=116 (11)	Hospital D n=50 (5)	Total n=983 (100)
Mean age years, mean (SD)	31 (5)	32 (5)	30 (5)	30 (4)	31 (5)
Gestational age days, mean (SD)	230 (49)	217 (60)	220 (58)	257 (31)	227 (53)
Parity**
Multiparous, n (%)*	371 (60)	112 (58)	86 (74)	28 (56)	597 (61)
Singleton, n (%)* ^‡	558 (89)	178 (92)	95 (93)	47 (94)	878 (89)
Number of cases where DOTTS overrruled, n	5	3	5	0	13
Urgency levels, n (%)*
U1 – Resuscitation and life-threatening	2 (0)	0 (0)	0 (0)	1 (2)	3 (0)
U2 – Emergency	406 (65)	118 (61)	71 (61)	27 (54)	622 (63)
U3 – Urgent	162 (26)	65 (34)	42 (36)	16 (32)	285 (29)
U4 – Not Urgent	54 (9)	10 (5)	3 (3)	6 (12)	73 (7)
Presenting symptoms, n (%)* ^^
Abdominal pain	166 (27)	60 (31)	26 (22)	11 (22)	263 (27)
Anxious pregnant woman/non-somatic symptoms	135 (22)	56 (29)	26 (22)	14 (28)	231 (23)
Vaginal fluid loss	93 (15)	21 (11)	11 (9)	11 (22)	36 (14)
Other physical symptoms	76 (12)	22 (11)	29 (25)	3 (6)	130 (13)
Vaginal bleeding	70 (11)	29 (15)	16 (14)	5 (10)	120 (12)
Two or more complaints	84 (13)	0 (0)	0 (0)	6 (12)	90 (9)

Notes: *Due to rounding the percentages do not add to 100%. **Missing Parity n=4. ^‡Missing Singleton n=14. ^{^}Missing Presenting symptoms n=13.

Figure 1 DOTTS compared with reference standard.

Table 2 Diagnostic Validity of the Dutch Obstetric Telephone Triage System for the Category “High Urgency” per Hospital

	Total Cases, (n)	Sensitivity % (95% CI)	Specificity % (95% CI)	Positive Predictive Value (PPV) % (95% CI)	Negative Predictive Value (NPV) % (95% CI)
All Hospitals	983	76 (72–80)	49 (44–53)	60 (56–63)	67 (62–72)
Hospital A	624	77 (69–86)	47 (41–52)	60 (55–64)	67 (61–74)
Hospital B	193	76 (61–91)	54 (44–65)	64 (55–72)	68 (57–79)
Hospital C	116	75 (54–96)	50 (38–63)	55 (43–67)	71 (58–85)
Hospital D	50	63 (37–88)	50 (30–70)	54 (35–72)	59 (38–80)

Table 3 Urgency of Care After Clinical Assessment

	Follow-Up After Assessment
Dutch Obstetric Telephone Triage System	Urgent Care, n (%)	Non-urgent care, n (%)	Total, n (%)
	Hospitalization – life threatening situation	Hospitalization without treatment or in labor after 37 weeks
	Hospitalization with treatment or in labor before 37 weeks	-Home after consultation
High Urgency*, n (%)	47 (60)	572 (64)	625 (64)
	5	89
	42	483
Intermediate urgency Urgency**, n (%)	31 (40)	321 (36)	358 (36)
	0	51
	31	270
Total (%)	78 (100)	893 (100)	983 (100)

Notes: *Missing high urgency 6. **Missing intermediate urgency 6.