Rates, costs and determinants of lumbar spine imaging in population-based women born in 1973-1978: Data from the Australian Longitudinal Study on Women's Health

ObjectiveThere are concerns that lumbar spine imaging represents low value care. Our aim was to examine the use of lumbar spine imaging [radiography, computed tomography (CT), magnetic resonance imaging (MRI)] over 20 years, and costs and person-level characteristics of imaging in a large cohort of Australian women.MethodsThe 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.Results38.9% 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. In women with self-reported back pain, depression and poorer physical 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 AU$51,735,649 over 2011-2015.ConclusionsLumbar spine imaging was common in population-based Australian women, with rates increasing over 20 years. Depression and poor physical health were associated with lumbar spine imaging. Raising awareness of this in clinicians is 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

Association between circulating 25-hydroxyvitamin D concentrations and hip replacement for osteoarthritis: a prospective cohort study

BACKGROUND: To examine the association between circulating 25(OH)D concentrations and incidence of total hip replacement for osteoarthritis in a prospective cohort study. METHODS: This study examined a random sample of 2651 participants in the Melbourne Collaborative Cohort Study who had 25(OH)D concentrations measured from dried blood spots collected in 1990-1994. Participants who underwent total hip replacement for osteoarthritis between January 2001 and December 2018 were identified by linking the cohort records to the Australian Orthopaedic Association National Joint Replacement Registry. Cox proportional hazard regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of total hip replacement for osteoarthritis in relation to 25(OH)D concentrations, adjusted for confounders. RESULTS: Eighty-six men and eighty-seven women had a total hip replacement for osteoarthritis. Compared with men in the lowest (1st) quartile of 25(OH)D concentration, the HR for total hip replacement was 2.32 (95% CI 1.05, 5.13) for those in the 2nd quartile, 2.77 (95% CI 1.28, 6.00) for those in the 3rd quartile, and 1.73 (95% CI 0.75, 4.02) for those in the highest quartile of 25(OH)D concentrations (p for trend 0.02). There was little evidence of an association in women. CONCLUSIONS: Higher circulating 25(OH)D concentrations were associated with an increased risk of total hip replacement for osteoarthritis in men but not in women. Although the underlying mechanism warrants further investigation, our findings highlight the need to determine the optimal levels of circulating 25(OH)D to reduce the risk of hip osteoarthritis

Severe low back or lower limb pain is associated with recurrent falls among older Australians

Background: Few studies have explored the impact of low back or lower limb pain severity on recurrent (≥2) falls in older adults. Objectives: Investigate the association between the severity of low back or lower limb pain, and ≥2 falls or falls-related injuries. Methods: Community-dwelling Australian males and females in the ASPREE Longitudinal Study of Older Persons (ALSOP), aged ≥70 years. Self-reported, cross-sectional questionnaire data regarding number of falls and falls-related injuries in the last 12 months; and sites and severity of pain experienced on most days. Adjusted relative risks (RR) were estimated from multivariable Poisson regression models, for males and females separately. Results: Of 14,892 ALSOP participants, 13% (n = 1983) reported ≥2 falls (‘recurrent fallers’) in the last 12 months. Males and females who reported severe low back, or severe lower limb pain on most days were more likely to report ≥2 falls in the last 12 months compared to those with mild pain (lower back: males RR = 1.70 and females RR = 1.5, p = 0.001; lower limb: males RR = 2.0, p < 0.001 and females RR = 1.4, p = 0.003). Female recurrent fallers who reported severe low back (RR = 1.3, p = 0.029) or lower limb (RR = 1.2, p = 0.024) pain on most days were more likely to report a falls-related injury in the last 12 months compared to females with mild pain. Conclusion: Severe low back or lower limb pain was associated with an increased likelihood of recurrent falls (males/females) or falls-related injuries (females only). Assessment of severe low back and lower limb pain should be considered as a priority when undertaking falls-risk evaluation. Significance: Severe low back pain, or severe lower limb pain is associated with an increased likelihood of recurrent falls in older males and females, and an increased likelihood of falls-related injuries in older female recurrent fallers. Assessment and management of severe low back and lower limb pain should be prioritized when undertaking falls-risk assessment. Future longitudinal research is required to further interrogate this relationship and its underlying mechanisms

Novel and systemic risk factors for knee and hip osteoarthritis

Osteoarthritis (OA) is a major public health problem and the most common cause of disability. Growing evidence suggests that OA is a disease of the whole joint. However, the etiology and risk factors of OA have not been fully elucidated, and there is no registered disease modifying drug to halt disease progression. Over recent years, new approaches and initiatives have been adapted for better understanding the disease pathology and mechanisms underlying the risk factors, such as the role of hormonal factors, metabolic and vascular factors, vitamin D and birth weight. This project attempted to investigate these systemic and novel risk factors for the incidence of knee and hip replacement for OA in linkage studies. In this thesis knee and hip replacement for OA were used as a surrogate for severe OA which provides evidence of the true problem and signifies the economic burden. The study populations were the participants of the Melbourne Collaborative Cohort Study and the Australian Diabetes, Obesity and Lifestyle Study which were linked to the Australian Orthopaedic Association National Joint Replacement Registry to determine the incidence of knee and hip replacement for OA. The initial focus of this thesis was on the association between hormonal factors and risk of total knee and hip replacement for OA. A lower estradiol concentration was a risk factor for total knee replacement for OA, while a lower androstenedione concentration and higher Sex Hormone Binding Globulin concentration were risk factors for total hip replacement for OA in women. Moreover, a lower index-to-ring finger length ratio, a proxy indicator of in-utero testosterone exposure, was associated with an increased risk of total knee replacement for OA but not the risk of total hip replacement for OA. The second part of this thesis examined the relationship between metabolic and vascular factors and the risk of knee and hip replacement for OA. The metabolic syndrome and cumulative number of metabolic syndrome components were both associated with increased risk of total knee replacement for OA, with no association observed for total hip replacement for OA. Additionally, retinal arteriolar narrowing was associated with increased risk of knee replacement for OA. These findings suggest that metabolic and vascular factors play a role in the pathogenesis of knee OA. The third part of this thesis examined the association between serum 25-hydroxy-vitamin D concentrations and the risk of hip replacement for OA. Higher serum 25-hydroxy-vitamin D concentrations were associated with an increased risk of hip replacement for OA in males but not in females. Finally, this thesis examined the association between birth weight and risk of knee and hip replacement for OA. Individuals born with low birth weight or preterm birth were at increased risk of hip replacement for OA but not knee replacement for OA in adult life. In conclusion, this thesis has made major contribution to the understanding of the role of hormonal factors, metabolic and vascular factors, serum 25-hydroxy-vitamin D concentration and birth weight in the pathogenesis of knee and hip OA. This thesis has highlighted the significant heterogeneity in terms of the risk factors for OA and that knee and hip OA are susceptible to different risk factors. This study has identified novel targets for the prevention and treatment of knee and hip OA separately that are likely to have an impact on this debilitating disease

Novel and systemic risk factors for knee and hip osteoarthritis

Osteoarthritis (OA) is a major public health problem and the most common cause of disability. Growing evidence suggests that OA is a disease of the whole joint. However, the etiology and risk factors of OA have not been fully elucidated, and there is no registered disease modifying drug to halt disease progression. Over recent years, new approaches and initiatives have been adapted for better understanding the disease pathology and mechanisms underlying the risk factors, such as the role of hormonal factors, metabolic and vascular factors, vitamin D and birth weight. This project attempted to investigate these systemic and novel risk factors for the incidence of knee and hip replacement for OA in linkage studies. In this thesis knee and hip replacement for OA were used as a surrogate for severe OA which provides evidence of the true problem and signifies the economic burden. The study populations were the participants of the Melbourne Collaborative Cohort Study and the Australian Diabetes, Obesity and Lifestyle Study which were linked to the Australian Orthopaedic Association National Joint Replacement Registry to determine the incidence of knee and hip replacement for OA. The initial focus of this thesis was on the association between hormonal factors and risk of total knee and hip replacement for OA. A lower estradiol concentration was a risk factor for total knee replacement for OA, while a lower androstenedione concentration and higher Sex Hormone Binding Globulin concentration were risk factors for total hip replacement for OA in women. Moreover, a lower index-to-ring finger length ratio, a proxy indicator of in-utero testosterone exposure, was associated with an increased risk of total knee replacement for OA but not the risk of total hip replacement for OA. The second part of this thesis examined the relationship between metabolic and vascular factors and the risk of knee and hip replacement for OA. The metabolic syndrome and cumulative number of metabolic syndrome components were both associated with increased risk of total knee replacement for OA, with no association observed for total hip replacement for OA. Additionally, retinal arteriolar narrowing was associated with increased risk of knee replacement for OA. These findings suggest that metabolic and vascular factors play a role in the pathogenesis of knee OA. The third part of this thesis examined the association between serum 25-hydroxy-vitamin D concentrations and the risk of hip replacement for OA. Higher serum 25-hydroxy-vitamin D concentrations were associated with an increased risk of hip replacement for OA in males but not in females. Finally, this thesis examined the association between birth weight and risk of knee and hip replacement for OA. Individuals born with low birth weight or preterm birth were at increased risk of hip replacement for OA but not knee replacement for OA in adult life. In conclusion, this thesis has made major contribution to the understanding of the role of hormonal factors, metabolic and vascular factors, serum 25-hydroxy-vitamin D concentration and birth weight in the pathogenesis of knee and hip OA. This thesis has highlighted the significant heterogeneity in terms of the risk factors for OA and that knee and hip OA are susceptible to different risk factors. This study has identified novel targets for the prevention and treatment of knee and hip OA separately that are likely to have an impact on this debilitating disease

Could low birth weight and preterm birth be associated with significant burden of hip osteoarthritis? A systematic review

Abstract Background Approaches for the prevention and treatment of hip osteoarthritis (OA) remain limited. There are recent data suggesting that low birth weight (LBW) and preterm birth may be risk factors for hip osteoarthritis. This has the potential to change the current paradigm of hip osteoarthritis prevention by targeting early life factors. The aim of this review was to examine the available evidence for an association of LBW and preterm birth with hip OA. The potential cost implications associated with total hip arthroplasty were also evaluated. Methods Ovid Medline, EMBASE, and Cinahl were searched up until August 2017 using MeSH terms and key words. Methodological quality was evaluated using the National Heart Lung and Blood Institute (NHLBI) quality assessment tool. Qualitative evidence synthesis was performed to summarise the results. Bradford Hill’s criteria for causation including the temporal relationship, consistency, strength of the association, specificity, dose-response relationship, and analogy were used to assess the evidence for causation. Economic modelling was used to calculate the potential economic burden associated with LBW or preterm birth related total hip arthroplasty using Australian data from 2012 to 2015. Results Five studies, ranging from high to low quality, were included. Hip bone shape abnormalities examined included developmental hip dysplasia and immature hip, and hip osteoarthritis included osteophytes and total hip arthroplasty. A causal link between low birth weight or preterm birth and hip osteoarthritis was found. Of the 30,477 total hip arthroplasties performed for hip osteoarthritis in Australia in 2015, 5791 were estimated to be born preterm and 5273 with low birth weight. This equated to a potential total hip arthroplasty cost of AU$145,136,082 and AU$132,150,222 for these subgroups, respectively. Conclusion Available data suggest that low birth weight and preterm birth are associated with hip bone shape abnormalities and hip osteoarthritis requiring total hip arthroplasty, with a substantial associated financial burden. Given the current lack of effective treatment and prevention strategies for hip osteoarthritis, this offers a new avenue for reducing the future burden of hip osteoarthritis