LAUSR

at 58 non-military hospitals in Washington State from 10/2015-9/ 2016. Data was obtained from the Washington State Comprehensive Hospital Abstract Reporting System (CHARS) which includes inpatient diagnosis with associated Present on Admission (POA) flags, procedure and discharge information derived from hospital billing systems. SMM was defined by CDC criteria. Deliveries were stratified by having or not having SMM. For deliveries with SMM diagnoses, POA rates were tabulated. Hospital SMM rates (all SMM, transfusion only, SMM excluding transfusion) were grouped according to their NICU Level of Care (Critical Access and 1-4). Odds ratios and 95% confidence intervals (CI) were calculated. RESULTS: Of 76,961 deliveries, 981 women (1.3%) had any SMM including 448 (0.58%) with SMM diagnoses/procedures and 533 (0.69%) with transfusion only. Level 1 and critical access hospitals had the highest transfusion rate (1.0%), while Levels 2,3 and 4 hospitals had progressively lower rates (Table; P<.001). Level 4 hospitals had the highest rate of SMM diagnoses/procedures (Table). Among those with SMM diagnoses, the percentage of women with diagnoses POA was highest in Level 4 NICU hospitals (Figure). CONCLUSION: SMM diagnoses occur most frequently at the centers providing the highest level of care in Washington State, likely attribiutable to the regional referral system. This is supported by the dose dependent relationship between POA and NICU levels. However, transfusion rates are increased in Level 1/critical access hospitals that may not be optimally equipped to handle maternal hemorrhage. Efforts to decrease SMM should focus on equipping Level 1 and critical access hospitals with tools to decrease maternal morbidity and improve referral systems.