Sevenfold rise in likelihood of pertussis test requests in a stable set of Australian general practice encounters, 2000–2011. Issue 11 (17th June 2013)

• Record Type: Journal Article
• Authors: Kaczmarek, Marlena C; Valenti, Lisa; Kelly, Heath A; Ware, Robert S; Britt, Helena C; Lambert, Stephen B
• Is Part Of: Medical journal of Australia. Volume 198:Issue 11(2013)
• Page Start: 624
• Page End: 628
• Publication Date: 2013-06-17
• Subjects: General medicine -- General medicine -- Infectious diseases -- Environment and public health; Medicine -- Periodicals; Medicine; Médecine -- Périodiques; Medicine; Periodical; Periodicals; Electronic journals; 610
• DOI: 10.5694/mja13.10044
• Languages: English
• ISSNs: 0025-729X

Abstract

Abstract: 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.