Factors influencing early and late mortality in adults with invasive pneumococcal disease in Calgary, Canada: a prospective surveillance study

PLoS One. 2013 Oct 8;8(10):e71924. doi: 10.1371/journal.pone.0071924. eCollection 2013.


Background: Invasive pneumococcal disease continues to be an important cause of mortality. In Calgary, 60% of deaths occur within 5 days of presenting to hospital. This proportion has not changed since before the era of penicillin. The purpose of this study was to investigate what factors may influence death within 5 days of presentation with pneumococcal disease.

Methods and findings: Demographic and clinical data from the CASPER (Calgary Area Streptococcus pneumoniae Epidemiology Research) study on 1065 episodes of invasive pneumococcal disease in adults (≥18 years) from 2000 to 2010 were analyzed. Adjusted multinomial regression was performed to analyze 3 outcomes: early mortality (<5 days post-presentation), late mortality (5-30 days post-presentation), and survival, generating relative risk ratios (RRR). Patients with severe disease had increased risk of early and late death. In multinomial regression with survivors as baseline, the risk of early death increased in those with a Charlson index ≥2 (RRR: 6.3, 95% CI: 1.8-21.9); the risk of late death increased in those with less severe disease and a Charlson ≥2 (RRR: 6.1, 95% CI: 1.4-27.7). Patients who never received appropriate antibiotics had 5.6X (95% CI: 2.4-13.1) the risk of early death. Risk of both early and late death increased by a RRR of 1.3 (95% CI: 1.2-1.4) per 5-year increase in age. In multinomial regression, there were no significant differences in the effects of the factors tested between early and late mortality.

Conclusions: Presenting with severe invasive pneumococcal disease, multiple comorbidities, and older age increases the risk of both early and late death. Patients who died early often presented too late for effective antibiotic therapy, highlighting the need for an effective vaccine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Canada / epidemiology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Pneumococcal Infections / mortality*
  • Population Surveillance
  • Prospective Studies
  • Risk Factors
  • Sex Factors
  • Time Factors

Grant support

This work and the CASPER project are supported in part by an unrestricted grant from Pfizer Canada (www.pfizer.ca) and the Alberta Children’s Hospital Foundation (www.childrenshospital.ab.ca) to Otto Vanderkooi and James Kellner. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.