Cohort study of Western Australia computed tomography utilisation patterns and their policy implications

Abstract

BackgroundComputed tomography (CT) scanning is a relatively high radiation dose diagnostic imaging modality with increasing concerns about radiation exposure burden at the population level in scientific literature. This study examined the epidemiology of adult CT utilisation in Western Australia (WA) in both the public hospital and private practice settings, and the policy implications.MethodsRetrospective cohort design using aggregate adult CT data from WA public hospitals and Medical Benefits Schedule (MBS) (mid-2006 to mid-2012). CT scanning trends by sex, age, provider setting and anatomical areas were explored using crude CT scanning rates, age-standardised CT scanning rates and Poisson regression modelling.ResultsFrom mid-2006 to mid-2012 the WA adult CT scanning rate was 129 scans per 1,000 person-years (PY). Females were consistently scanned at a higher rate than males. Patients over 65 years presented the highest scanning rates (over 300 scans per 1,000 PY). Private practice accounted for 73% of adult CT scans, comprising the majority in every anatomical area. In the private setting females predominately held higher age-standardised CT scanning rates than males. This trend reversed in the public hospital setting. Patients over 85 years in the public hospital setting were the most likely age group CT scanned in nine of ten anatomical areas. Patients in the private practice setting aged 85+ years were relatively less prominent across every anatomical area, and the least likely age group scanned in facial bones and multiple areas CT scans.ConclusionIn comparison to the public hospital setting, the MBS subsidised private sector tended to service females and relatively younger patients with a more diverse range of anatomical areas, constituting the majority of CT scans performed in WA. Patient risk and subsequent burden is greater for females, lower ages and some anatomical areas. In the context of a national health system, Australia has various avenues to monitor radiation exposure levels, improve physician training and modify funding mechanisms to ensure individual and population medical radiation exposure is as low as reasonably achievable.

Medical Imaging Outpatients' Experiences With Receiving Information Required for Informed Consent and Preparation: A Cross-Sectional Study

“…Findings may not generalize beyond the single, large metropolitan medical imaging department study setting. However, the age and gender profile of the sample was similar to that of participants in other large Australian (38,39) and international studies (40,41) with medical imaging outpatients.…”

Increase in computed tomography in Australia driven mainly by practice change: A decomposition analysis

“…Finally, data from public hospitals are omitted from this analysis. An earlier cohort study using data from Western Australia found that 74% of CT scans performed from 2006/7 through 2011/12 were billed to Medicare, rather than delivered in a public hospital (2). This analysis found differences between CT in public and private settings.…”

“…Previous work in Western Australia found the greatest changes per 1,000 population from 2006/7 to 2011/12 were for interventional CT (7.3 to 11.4), followed by facial bones (8.3 to 9.7) (2). MBS-billed CT of the spine reduced from 20.8 to 18.8 per 1,000 population(2).While the proportionate contribution of population size increased over the study period, the change in population distribution explains less than 10% of the change in CT count and cost over all compared time periods included in the analysis, despite a shift to the right. However, this is relative to population growth and non-population size/distribution factors and it is clear that some changes in CT distribution have occurred, including an increase in CT for those aged 85 years or above.…”

Trends in utilisation of ultrasound by older Australians (2010–2019)

“…More recent reports indicate that computed tomography (CT) now tends to be ordered in preference to other modalities for the evaluation of abdominal issues [ 17 , 23 ]. Older people are major CT users in Australia and elsewhere [ 17 , 23 , 24 ]. In the USA for example, 11% of all emergency department presentations for abdominal pain have CT scans,[ 23 , 24 ] and its use has increased tenfold between 1997 and 2016, while the utilisation of abdominal ultrasound plateaued between 1997 and 2011 [ 23 ].…”