Increased long-term mortality after survival of invasive pneumococcal disease: a population-based study

We studied if patients surviving hospitalization for invasive pneumococcal disease (IPD) have an increased long-term mortality.

In this population-based case-control study, we assessed adults discharged from Aker University Hospital in Oslo, Norway, from 1993 to 2008 after surviving IPD. Mortality among the study population was compared to the general Norwegian population using standardized mortality ratios (SMR). Median follow-up time was 7.2 years (range 5 days to 21.1 years). Associated factors were also investigated.

We assessed 372 patients of whom 184 patients died during the observation period. Mortality was increased for 10 years after surviving hospitalization for IPD. Patients aged 18-64 years had a one-year SMR of 18.8 (95% CI: 10.0-32.1) and a 10-year SMR of 6·0 (95% CI: 4.4-8.0). SMR for the first five years among patients with and without underlying conditions were 10.7 (95% CI: 7.0-15.5) and 2.8 (95% CI: 0.9-6.4), respectively. Patients older than 65 years had a one-year SMR of 1·8 (95% CI: 1.2-2.7) and a 10-year SMR of 1.6 (95% CI: 1.4-1.9).

Patients surviving IPD had an increased long-term mortality compared to the general population. This was particularly pronounced in patients with known underlying conditions. These findings suggest that IPD is a negative prognostic marker, and that a closer follow-up of patients who have suffered IPD is warranted.