Inhospital death is a biased measure of fatal outcome from bloodstream infection

Abstract

Purpose

Inhospital death is commonly used as an outcome measure. However, it may be a biased measure of overall fatal outcome. The objective of this study was to evaluate inhospital death as a measure of all-cause 30-day case fatality in patients with bloodstream infection (BSI).

Patients and methods

A population-based surveillance cohort study was conducted, and patients who died in hospital within 30 days (30-day inhospital death) were compared with those who died in any location by day 30 post BSI diagnosis (30-day all-cause case fatality).

Results

A total of 1,773 residents had first incident episodes of BSI. Overall, 299 patients died for a 30-day all-cause case fatality rate of 16.9%. Most (1,587; 89.5%) of the patients were admitted to hospital, and ten (5.4%) of the 186 patients not admitted to hospital died. Of the 1,587 admitted patients, 242 died for a 30-day inhospital death rate of 15.2%. A further 47 patients admitted to hospital died after discharge but within 30 days of BSI diagnosis for a 30-day case fatality rate among admitted patients of 18.2%. Patients who died following discharge within 30 days were older and more likely to have dementia.

Conclusion

The use of inhospital death is a biased measure of true case fatality.

Keywords:

• mortality
• case fatality
• bacteremia

Acknowledgments

This study was supported in part by the Strand Infectious Diseases Innovation Fund, Royal Inland Hospital Foundation. The sponsor had no role in the conception, conduct, or reporting of the study.

Author contributions

All the authors substantially contributed to conception and design, data acquisition, or data analysis and interpretation. All the authors contributed to the drafting of the article or critically revising it for important intellectual content. All the authors provided the final approval of the version to be published, and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of the work are appropriately investigated and resolved.

Disclosure

The authors report no conflicts of interest in this work.