The Accuracy of Reporting of the Hypertensive Disorders of Pregnancy in Population Health Data

Figures & data

Table 1: Rates of hypertension in the validation study and population health data sets (PHDS)

Type of hypertension	No. of “true” cases	Rates of hypertension by data source (%)
		Validation study	Birth data	Hospital data	Either birth or hospital data
Any hypertension	178	9.5	6.2	7.2	8.0
Any Chronic hypertension	25	1.3	0.5	0.6	0.8
Any Pregnancy hypertension	165	8.3	5.7	6.0	7.5
Gestational hypertension	72	6.2		3.8
Preeclampsia	93	2.1		2.3

*Percentages are weighted for the sampling probability.

Table 2: Characteristics of PHDS reporting compared with the true occurrence of disease as abstracted from the medical record

Hypertension type	Reporting characteristics by PHDS source % (95% confidence interval)
	Birth data				Hospital data				Either birth or hospital data
	Sensitivity	Specificity	PPV	κ	Sensitivity	Specificity	PPV	κ	Sensitivity	Specificity	PPV	κ
Chronic hypertension	22.6 (5.7–50.7)	99.8 (99.3–100)	56.3 (15.7–91.2)	0.32	44.4 (19.7–71.3)	100 (99.7–100)	100 (57.9–100)	0.61	46.9 (21.6–73.4)	99.8 (99.3–100)	72.7 (36.9–94.7)	0.57
Gestational hypertension	—	—	—	—	47.8 (36.0–59.8)	99.2 (98.4–99.6)	78.9 (64.1–89.7)	0.58	—	—	—	—
Preeclampsia	84.7 (64.8–95.8)	96.0 (94.7–97.1)	31.6 (20.8–44.0)	0.44	71.0 (49.7–87.1)	99.2 (98.5–99.6)	66.7 (46.0–83.5)	0.68	99.1 (84.8–100)	95.8 (94.4–96.9)	33.8 (23.2–45.7)	0.49
Any pregnancy hypertension	63.3 (53.0–72.8)	99.5 (98.9–99.8)	92.4 (83.3–97.4)	0.73	68.2 (58.1–77.2)	99.6 (99.1–99.9)	94.4 (86.2–98.4)	0.78	82.3 (73.3–89.3)	99.3 (98.7–99.7)	91.9 (84.1–96.6)	0.86
Age <35 years	67.7 (56.3–77.7)	99.4 (98.7–99.8)	91.5 (81.3–97.1)	0.76	74.7 (63.7–83.7)	99.6 (98.9–99.9)	93.9 (84.9–98.4)	0.82	88.8 (79.8–94.8)	99.2 (98.4–99.7)	91.1 (82.4–96.3)	0.89
Age ≥35 years	44.6 (21.9–69.1)	100 (98.1–100)	99.1 (62.9–100)	0.59	40.2 (18.5–65.1)	99.9 (98.0–100)	98.3 (58.9–100)	0.55	54.0 (29.7–77.0)	99.9 (97.9–100)	98.0 (66.5–100)	0.68
Primiparous	72.9 (57.5–85.1)	100 (99.1–100)	99.8 (89.0–100)	0.83	80.1 (65.5–90.5)	100 (99.1–100)	99.8 (89.8–100)	0.88	92.6 (80.7–98.3)	100 (99.1–100)	99.7 (90.9–100)	0.96
Multiparous	55.4 (41.3–69.0)	99.2 (98.2–99.7)	85.5 (69.4–95.0)	0.65	58.3 (44.1–71.6)	99.4 (98.5–99.8)	88.9 (73.8–96.9)	0.69	73.8 (60.0–84.8)	98.9 (97.8–99.6)	84.9(71.5–93.7)	0.77
Any hypertension	65.0 (55.4–73.7)	100 (99.6–100)	99.8 (94.7–100)	0.77	73.8 (64.7–81.7)	99.8 (99.3–100)	97.6 (91.7–99.7)	0.83	81.4 (73.0–88.1)	99.8 (99.3–100)	97.7 (92.2–99.7)	0.88

*% are weighted for the sampling probability.

PPV = positive predictive value.

κ =  kappa statistic.

Table 3: Rates of validated adverse outcomes by source of pregnancy hypertension report

Data source	Women with pregnancy-related hypertension,	Validated outcomes %
		Severe preeclampsia	Preterm <37 weeks	Maternal morbidity
“True” pregnancy hypertension	165	10.6	9.0	4.9
Hypertension Reporting Source
Birth data alone	109	14.5	13.0	6.5
Hospital data alone	142	15.5	13.2	6.9
Either hospital or birth data	157	12.8	11.0	5.7
Both hospital and birth data	94	18.7	16.7	8.4

*Weighted percentage of validated adverse outcomes among women with pregnancy hypertension.

^†Number of women in the validation study with pregnancy-related hypertension according to the data source.

^‡'True' rates of adverse outcomes among women with any pregnancy-related hypertension, according to the medical records. The subsequent rows show that those with severe disease or poor outcomes are more likely to be reported in PHDS but the differences were not statistically significant (p> 0.1).