Burden of pneumococcal disease in adults aged 65 years and older: an Australian perspective

Abstract

Background: The burden of pneumococcal disease in adults aged 65 years and older in Australia is not well defined. This retrospective cross-sectional study calculated rates for pneumococcal pneumonia using data from the Australian Institute of Health and Welfare and from the Bettering Evaluation and Care of Health program.

Methods: Invasive pneumococcal disease (IPD) incidence was calculated using National Notifiable Diseases Surveillance System data. Population estimates and pneumonia mortality data were from the Australian Bureau of Statistics. Medical costs were derived from Australian Refined Diagnosis Related Groups and the literature. Clinical and economic burden of pneumococcal pneumonia hospitalisations and general practitioner (GP) visits were described and compared with IPD.

Results: For adults aged ≥65 years, pneumococcal pneumonia hospitalisation incidence was 274 per 100,000 population in 2011-2012. From 2004 to 2012, a mean of 2235 pneumonia hospitalisation deaths were recorded, corresponding to a case fatality rate of 6.1 %. GP visits accounted for the largest portion of healthcare encounters, with an annual average of 455 pneumococcal pneumonia GP visits per 100,000 population from 2008 to 2013. In 2012, IPD incidence was 19 per 100,000 population. The estimated annual costs of treating pneumococcal pneumonia hospitalisations and GP visits were A$55,722,136 and A$1,604,189, respectively. Estimated costs for IPD were A$1,172,986.

Conclusions: The healthcare and economic burden of pneumococcal disease in adults aged ≥65 years in Australia is substantial, with the incidence of pneumococcal pneumonia hospitalisation nearly 15-fold higher than for IPD. Despite this, it remains less recognised than other infectious diseases such as influenza.

Keywords: Adults; Burden of disease; Pneumococcal disease; Pneumonia; Streptococcus pneumoniae.

Fig. 1

All-cause pneumonia hospitalisations for financial years 2001–2012. Incidence of all-cause pneumonia hospitalisations are shown per 100,000 population for adults aged 65–74 years, 75–84 years, ≥85 years, and all 3 age groups combined

Fig. 2

Distribution of pneumococcal disease (a) incidence and (b) associated costs. Estimated incidence per 100,000 population and costs associated with IPD, pneumococcal pneumonia hospitalisation, and pneumococcal pneumonia GP visits. Data for IPD are also shown by clinical presentation (pneumonia, bacteraemia and meningitis). GP, general practitioner; IPD, invasive pneumococcal disease