@misc{indiciaef6161b090cbb,
  title = {Risk stratification for open heart surgery.},
  author = {D J Spiegelhalter},
  year = {1992},
  doi = {10.1136/bmj.305.6867.1500-a},
  url = {https://pubmed.ncbi.nlm.nih.gov/1493411/},
  note = {Source identifier: 1493411}
}