OP 31 The effect of ethnicity on the performance of protein-creatinine ratio in the prediction of significant proteinuria in pregnancies at risk of or with established hypertension – An implementation audit and cost implications

Background The replacement of 24-h urine collection by protein-creatinine ratio (PCR) as one of the diagnostic criteria for pre-eclampsia has been recently recommended. However, the literature is conflicting and there are concerns on the impact of demographic factors on the performance of PCR as a screening tool. Methods This was an implementation audit of the introduction of PCR in a London Tertiary obstetric unit. Women with suspected pre-eclampsia ( N  = 476) were asked to complete a 24-h urine collection and an untimed urine sample for PCR calculation. Multivariate logistic regression was used to assess the independent predictors of significant proteinuria. Results In a pregnant population ethnicity and PCR are the main predictors of 300 mg or more of proteinuria in a 24-h urine collection. With a PCR cut-off of 30 mg/mmol, 41.4% and 22.9% of black and non-black women, respectively, would have been incorrectly classified as non-proteinuric. Sensitivity of 100% is achieved at cut-offs of 8.67 and 20.56 mg/mmol for black and non-black women, respectively. Applying these levels as a primary screening tool to inform for the need to perform a 24-h urine collection in 1000 women, it would lead to a financial saving of £2587 in non-black and to a loss of £2905 black women, respectively. Conclusions PCR has 100% sensitivity and is cost efficient in non-black pregnant women, at a cut-off of 20.5 mg/mmol, in the detection of more than 300 mg in a 24-h urine collection. However, in black pregnant populations the performance of PCR is both clinically and financially suboptimal. Download high-res image (77KB) Download full-size image Download high-res image (133KB) Download full-size image