Sevenfold rise in likelihood of pertussis test requests in a stable set of Australian general practice encounters, 2000–2011

Marlena C Kaczmarek, Lisa Valenti, Heath A Kelly, Robert S Ware, Helena C Britt and Stephen B Lambert
Med J Aust 2013; 198 (11): 624-628. || doi: 10.5694/mja13.10044


Objective: To better understand the role that diagnostic test-ordering behaviour of general practitioners has on current pertussis epidemiology in Australia.

Design and setting: Analysis of Australian general practice encounter data (from the Bettering the Evaluation and Care of Health [BEACH] program) on 13 “pertussis-related problem” (PRP) codes that were most likely to result in a pertussis laboratory test request and Australian pertussis notifications data (from the National Notifiable Diseases Surveillance System [NNDSS]) for the period April 2000 to March 2011.

Main outcome measures: The change in the proportion of PRP general practice encounters with a pertussis test request between 2000 and 2011, and the change in national pertussis notifications over the same period.

Results: The proportion of PRP encounters resulting in a pertussis test request increased from 0.25% between April 2000 and March 2004 to 1.71% between April 2010 and March 2011 (odds ratio, 7.0; 95% CI, 5.5–8.8). The BEACH data on pertussis testing and NNDSS data on pertussis notifications were highly correlated (r = 0.99), and the notification data mirrored the likelihood of a pertussis test request in general practice. The proportion of NNDSS pertussis notifications with a polymerase chain reaction (PCR)-confirmed diagnosis increased from 16.3% between April 2000 and March 2004 to 65.3% between April 2010 and March 2011.

Conclusion: An increase in pertussis testing following recognition of early epidemic cases may have led to identification of previously undetected infections, resulting in a further increase in notified disease and awareness among GPs. The changing likelihood of being tested may also be due to expanding availability and use of PCR testing in Australia.

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  • Marlena C Kaczmarek1,2,3
  • Lisa Valenti4
  • Heath A Kelly3
  • Robert S Ware1,2
  • Helena C Britt4
  • Stephen B Lambert1

  • 1 Queensland Children’s Medical Research Institute, Brisbane, QLD.
  • 2 School of Population Health, University of Queensland, Brisbane, QLD.
  • 3 Victorian Infectious Diseases Reference Laboratory, Melbourne, VIC.
  • 4 Family Medicine Research Centre, School of Public Health, University of Sydney, Sydney, NSW.


We thank the Australian Government Department of Health and Ageing and the Family Medicine Research Centre, School of Public Health, University of Sydney, for providing data used in this study. Marlena Kaczmarek is the recipient of a Sidney Myer Health Scholarship. During the data period included in this study, the BEACH program was funded by: the Australian Government Department of Health and Ageing (1998–2004, 2007–2011); the National Prescribing Service (2005–2009); AstraZeneca (Australia) (1998–2011); Merck, Sharp and Dohme (Australia) (2002–2011); Pfizer Australia (2003–2011); Sanofi-Aventis Australia (2006–2011); Novartis Pharmaceuticals Australia (2009–2011); GlaxoSmithKline Australia (2010–2011); CSL Biotherapies (2010–2011); Bayer Australia (2010–2011); Janssen-Cilag (2000–2010); Abbott Australasia (2006–2010); Wyeth Australia (2008–2010); Roche Products (1998–2006); and Aventis Pharma (1998–2002).

Competing interests:

Stephen Lambert has received honoraria for serving on the GlaxoSmithKline advisory boards for pneumococcal conjugate vaccine, serving as an investigator on clinical studies sponsored by GlaxoSmithKline and Sanofi-Pasteur (both manufacturers of pertussis-containing vaccines), and serving on GlaxoSmithKline and Sanofi-Pasteur advisory boards for pneumococcal and influenza vaccines, respectively.

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