Table 4.

Medical record review on discrepant cases meeting different hypertension identification algorithms

Set A: Among pregnancies with multiple hypertension diagnosis codes during pregnancy and thus would have been identified by a diagnosis-based approach, those that did not meet our hypertension case definition
Of the base 566,624 eligible pregnancies, 17,742 had multiple hypertension diagnosis codes during pregnancy. Of them, 3,933 (22.2%) were not identified as hypertensive by our approach. Of the 50 charts reviewed from this group: 8 (16.0%) filled antihypertensive medications. They did not meet our definition of hypertension either because the timing of the fill and the diagnosis code was not within our specified time window (n=4) or prescriptions were filled outside of KP facility. 14 (28.0%) had 2 or more BP of 140/90 or higher. They were not identified by our approach because none of these high BP were within 30 days.
Set B: Among pregnancies met our High BP criterion, those did not have a hypertension diagnosis code. They would have been missed by a diagnosis-based approach.
Of the 24,140 pregnancies met the High BP criterion (2 or more BP ≥140/90), 7,559 (31.3%) did not receive a hypertension diagnosis code. Of the 55 charts reviewed from this group: 32 (58.1 %) had a clinical statement about hypertension, white coat hypertension or high BP. 3 (5.5%) filled antihypertensive medications 13 (23.6%) had documentations of acute illness in situations when 1 of their high BP was measured
Set C: Among pregnancies treated with antihypertensive medications, those did not meet our hypertension case definition.
Of the base 566,624 eligible pregnancies, 7,737 were treated with methyldopa or labetalol. Of them, 741 (9.6%) were not identified as hypertensive by our approach. Of the 20 charts reviewed from this group: 15 (75.0%) had documentation in the charts that they were using the medication to treat hypertension. 10 (50.0%) received a diagnosis within 7 days of an antihypertensive medication fill, but none also had a high BP within this time window to qualify our Rapid Treatment criterion. 6 (30.0%) had 2 or more BP ≥140/90. Of them, 3 had high BP within 30 days and thus would have met our High BP criterion. However, the BP information was found in clinical notes only (not in structured electronic medical record data), due to reasons such as receiving care outside of our facility or self-reporting BP. Of the base 566,624 eligible pregnancies, 5,288 were treated with other antihypertensive medications. Of them, 2,451 (46.4%) were not identified as hypertensive by our approach. Of the 25 charts reviewed from this group: 4 (16.0%) had documentation in the charts that they were using the medication to treat hypertension 2 (8.0%) received a diagnosis within 7 days of an antihypertensive medication fill, but neither also had a high BP within this time window to quality our Rapid Treatment criterion. None had 2 or more BP ≥140/90 any time during pregnancy