Comment on “Comparison of C-reactive protein and C-reactive protein-to-albumin ratio in predicting mortality among geriatric coronavirus disease 2019 patients”

Dear Editor,

We read with great interest a retrospective cohort study entitled “Comparison of C-reactive protein and C-reactive protein-to-albumin ratio in predicting mortality among geriatric coronavirus disease 2019 patients” by Rohat et al.¹, who investigated the value of C-reactive protein and C-reactive protein-to-albumin ratio in predicting mortality in geriatric coronavirus disease 2019 (COVID-19) patients. In this study involving 404 participants, the authors found that both serological indicators were important in predicting mortality in elderly COVID-19 patients. However, in our opinion, we have some concerns which need clarification.

First, a detailed elucidation of the cause responsible for the mortality is extremely necessary. Notably, the population of this study1 was patients over the age of 65 years. In the vast majority of cases, mortality was caused by the underlying diseases (such as chronic obstructive pulmonary disease, coronary heart disease, or malignant tumor)²,³, but not COVID-19. The existence of COVID-19 is likely to be a coincidence and not a major factor responsible for the mortality. Therefore, it is highly recommended to provide detailed information on patient's mortality.

Second, in Table 11, there were significant differences in baseline characteristics between survivor and nonsurvivor patients. Remarkably, the nonsurvivor patients were older (78 years vs. 75 years) and had a higher incidence of congestive heart failure (57.8 vs. 42.2%) and chronic renal failure (65.6 vs. 34.4%) compared with the survivor patients. Advanced age⁴, congestive heart failure⁵, and chronic renal failure⁶ are all important factors leading to a significant increase in mortality. In particular, congestive heart failure and chronic renal failure are also common reasons in patients present to the emergency department. In this case, the abnormal C-reactive protein and C-reactive protein-to-albumin ratios are most likely due to congestive heart failure and chronic renal failure, but not COVID-19. Therefore, it is reasonable to assume that there is no definite correlation between the abnormal C-reactive protein-to-albumin ratio and COVID-19. From our perspective, one of the best solutions is to adjust potential confounding factors when ROC curve was calculated, in order to truly obtain the value of C-reactive protein and C-reactive protein-to-albumin ratio in predicting mortality in elderly COVID-19 patients.

• Funding: none.

REFERENCES

• ¹
  Ak R, Doğanay F, Yilmaz E. Comparison of C-reactive protein and C-reactive protein-to-albumin ratio in predicting mortality among geriatric coronavirus disease 2019 patients. Rev Assoc Med Bras (1992). 2022;68(1):82-6. https://doi.org/10.1590/1806-9282.20210811
  » https://doi.org/10.1590/1806-9282.20210811
• ²
  Dajczman E, Robitaille C, Ernst P, Hirsch AM, Wolkove N, Small D, et al. Integrated interdisciplinary care for patients with chronic obstructive pulmonary disease reduces emergency department visits, admissions and costs: a quality assurance study. Can Respir J. 2013;20(5):351-6. https://doi.org/10.1155/2013/187059
  » https://doi.org/10.1155/2013/187059
• ³
  Kim Y, Soffler M, Paradise S, Jelani QU, Dziura J, Sinha R, et al. Depression is associated with recurrent chest pain with or without coronary artery disease: A prospective cohort study in the emergency department. Am Heart J. 2017;191:47-54. https://doi.org/10.1016/j.ahj.2017.06.003
  » https://doi.org/10.1016/j.ahj.2017.06.003
• ⁴
  Boyle PA, Buchman AS, Barnes LL, James BD, Bennett DA. Association between life space and risk of mortality in advanced age. J Am Geriatr Soc. 2010;58(10):1925-30. https://doi.org/10.1111/j.1532-5415.2010.03058.x
  » https://doi.org/10.1111/j.1532-5415.2010.03058.x
• ⁵
  Dokainish H, Teo K, Zhu J, Roy A, AlHabib KF, ElSayed A, et al. Global mortality variations in patients with heart failure: results from the International Congestive Heart Failure (INTER-CHF) prospective cohort study. Lancet Glob Health. 2017;5(7):e665-72. https://doi.org/10.1016/S2214-109X(17)30196-1
  » https://doi.org/10.1016/S2214-109X(17)30196-1
• ⁶
  Erkocak OF, Yoo JY, Restrepo C, Maltenfort MG, Parvizi J. Incidence of infection and inhospital mortality in patients with chronic renal failure after total joint arthroplasty. J Arthroplasty. 2016;31(11):2437-41. https://doi.org/10.1016/j.arth.2016.04.031
  » https://doi.org/10.1016/j.arth.2016.04.031

Publication Dates

• Publication in this collection
  21 Nov 2022
• Date of issue
  2022

History

• Received
  03 July 2022
• Accepted
  08 July 2022