Rates, costs and determinants of lumbar spine imaging in population-based women born in 1973-1978: a prospective cohort study

Abstract

Purpose: Lumbar spine imaging for non-specific low back pain is designated as low value care. Of concern is the overuse of lumbar spine imaging, including radiography, computed tomography (CT) and magnetic resonance imaging (MRI), which is discordant with the clinical guidelines. The aim of this study was to examine the use of lumbar spine imaging over 20 years, and costs and person-level characteristics associated with lumbar spine imaging in a large cohort of Australian women. Methods: The Australian Longitudinal Study on Women’s Health (ALSWH) is a longitudinal population-based survey of women randomly selected from national health insurance scheme (Medicare) database. This study examined 13458 women born in 1973-1978 who consented to link their ALSWH and Medical Benefits Scheme records. Self-reported data on demographics, body mass index, depression, physical and mental health, and back pain were collected in each survey performed in 1996, 2000, 2003, 2006, 2009, 2012, and 2015. Data on lumbar spine imaging from 1996 to 2015 were obtained from the Medical Benefits Scheme database. Results: 38.9% of women underwent some form of lumbar spine imaging over 20 years. While radiography increased from 1996 to 2011 and decreased thereafter, CT and MRI continued to increase from 1996 to 2015. The increased imaging rates were not simply due to ageing, but also time period related factors. In women with self-reported back pain, depression and poorer physical and mental health were associated with imaging, with no significant differences in types of imaging. Based on imaging rates in ALSWH, the estimated costs for Australian women aged 30-39 years were $51,735,649 over 2011-2015, with a potential cost saving of >$36 million in this population alone if clinical guidelines were followed. Conclusions: Lumbar spine imaging was common in population-based Australian women, with rates increasing from 1996 to 2015 which were explained by effect of ageing and time period. This study highlights the potential for substantial cost savings if imaging was performed as recommended by clinical guidelines. Depression, physical and mental health were associated with lumbar spine imaging. Targeting women with these conditions and raising awareness of this in primary care providers are likely to result in significant cost savings if clinical guidelines are followed, with the potential of freeing resources for high value care and health outcomes.