@misc{indiciae905655868654,
  title = {A new method of classifying prognostic comorbidity in longitudinal studies: development and validation.},
  author = {M E Charlson and P Pompei and K L Ales and C R MacKenzie},
  year = {1987},
  doi = {10.1016/0021-9681(87)90171-8},
  url = {https://pubmed.ncbi.nlm.nih.gov/3558716/},
  note = {Source identifier: 3558716}
}