Discriminatory Accuracy of Preeclampsia Risk Factors in Primary Care.

BACKGROUND: Although it is common to use risk factors in the screening for preeclampsia, they do not always accurately identify patients who truly have this condition. AIM OF THE STUDY: To determine the discriminatory accuracy of known preeclampsia risk factors, both individually and in combination. METHODS: We studied patients undergoing prenatal care who were diagnosed with preeclampsia or eclampsia (n = 160 cases) in primary care and those who were not (n = 430 controls). Data on history of preeclampsia, type 2 diabetes, chronic hypertension, multiple gestation, first pregnancy, pregnancy interval ≥10 years, overweight/obesity, mean arterial pressure (MAP) ≥80 mmHg, and age (<20 years and ≥40 years) were obtained using a dichotomous scale. Discriminatory accuracy indicators were true-positive (TP) and false-positive (FP) rates, positive and negative likelihood ratios (LR+ and LR-), diagnostic odds ratio (DOR), and the area under the receiver-operating characteristic (AUROC) curve; stratified by parity. The case-control status was the reference standard. RESULTS: Certain combinations performed better than individual factors, independent of parity status. Among multiparous women, MAP ≥80 mmHg together with previous preeclampsia and overweight/obesity accumulated the greatest number of discriminatory accuracy indicators, with acceptable values: TP, 72.2%; FP, 1.5%; LR+, 48.4; LR-, 0.3; DOR, 171.6; and AUROC, 0.85. CONCLUSIONS: Discriminatory accuracy was low for almost all individual preeclampsia risk factors. However, the accuracy improved after some factors were combined. To the best of our knowledge, this is the first study to examine the discriminatory accuracy of preeclampsia risk factors used for screening high-risk pregnancies in primary care in Mexico.

Comparison of the discriminatory accuracy of four risk criteria for preeclampsia.

OBJECTIVES: Several criteria have been proposed to categorize the risk of preeclampsia, with notable differences between these criteria. We compared the discriminatory accuracy of criteria for categorizing preeclampsia risk established by four institutions, namely, the World Health Organization (WHO), National Institute for Health and Care Excellence (NICE), American College of Obstetricians and Gynecologists (ACOG), and National Center for Technological Excellence in Health (CENETEC), and estimated the concordance between these criteria. STUDY DESIGN: We performed a secondary data analysis of 590 Mexican obstetric patients who received prenatal care in primary care between 2016 and 2017; 160 had a diagnosis of preeclampsia. MAIN OUTCOME MEASURES: We estimated the true (TP) and false positive (FP) fractions, positive (PPV) and negative predictive values (NPV), positive (LR+) and negative (LR-) likelihood ratios, diagnostic odds ratio (DOR), area under the receiver operating characteristic curve (AUROC), and Kappa coefficient with corresponding 95% confidence intervals (CIs). RESULTS: Only the WHO criteria, followed by the NICE criteria, had the greatest number of accuracy indicators with ideal or acceptable results: TP 83.6%, PPV 60.5%, NPV 90.3%, DOR 14.3, and AUROC 0.79 and TP 84.5%, PPV 51.0%, NPV 90.3%, DOR 9.7, and AUROC 0.74, respectively. The Kappa coefficient between WHO and NICE criteria was 0.78 (95% CI 0.71-0.85). CONCLUSIONS: The discriminatory accuracies of the WHO and NICE criteria were superior to those of the ACOG and CENETEC criteria for classifying preeclampsia risk. Their concordance was good; thus, both criteria seem appropriate for screening preeclampsia in primary care.