Validation study of obstetric hospitalization data held on the Brazilian National Health System Hospital Information System for maternal morbidity surveillance: Brazil, 2021-2022

ABSTRACT Objective To validate the Brazilian National Health System Hospital Information System (SIH/SUS) for maternal morbidity surveillance. Methods This was a cross-sectional study conducted in 2021/2022, taking as its reference a national study on maternal morbidity (MMG) conducted in 50 public and 28 private hospitals; we compared SIH/SUS and MMG data for hospitalization frequency, reason and type of discharge and calculated sensitivity, specificity, positive and negative likelihood ratios for seven diagnoses and four procedures. Results Hospitalizations identified on SIH/SUS (32,212) corresponded to 95.1% of hospitalizations assessed by MMG (33,867), with lower recording on SIH/SUS (85.5%) for private hospitals [10,036 (SIH/SUS)]; 11,742 (MMG)]; compared to MMG, SIH/SUS had a lower proportion of hospitalizations due to “complications during pregnancy” (9.7% versus 16.5%) as well as under-recording of all diagnoses and procedures assessed, except “ectopic pregnancy”. Conclusion Better recording of diagnoses and procedures on SIH/SUS is essential for its use in maternal morbidity surveillance.