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Background Blood concentrations of testosterone and estrone tend to increase in women aged ≥70 years, whereas concentrations of their precursor hormone dehydroepiandrosterone decline. It is unknown whether these changes influence physical function. We investigated whether concentrations of these hormones were associated with grip strength and self-reported physical function in community-dwelling older women. Methods A total of 9 179 Australian women, aged ≥70 years, were recruited to the ASPirin in Reducing Events in the Elderly (ASPREE) trial. Sex hormones were measured in Sex Hormones in Older Women, an ASPREE substudy, by liquid chromatography–tandem mass spectrometry in 6 358 women. The associations between hormone concentrations and physical function (handgrip strength and self-reported physical function assessed by SF-12v2 physical component summary [PCS]) were examined using multiple linear regression. Results The median age of the 5,447 participants was 74.0 (interquartile range 71.7–77.6) years. Testosterone concentrations above the lowest quartile were associated with less decline in grip strength (mean –1.39 [95% CI –1.54 to –1.24] vs –1.75 [–2.00 to –1.50] kg, p  = .02), and dehydroepiandrosterone concentrations above the lowest quartile were associated with less decline in grip strength (–1.39 [–1.54 to –1.25] vs –1.82 [–2.11 to –1.55] kg, p  = .007) and PCS scores (–1.49 [–1.80 to –1.17] vs –2.33 [–2.93 to –1.72], p  = .02) over 4 years, compared with those in the respective lowest quartile. Conclusions Low endogenous concentrations of testosterone and dehydroepiandrosterone were associated the greatest likelihood of physical function decline in community-based women aged ≥70 years. Further studies are warranted to determine whether testosterone and dehydroepiandrosterone therapy prevent functional decline in this at-risk group using sensitive measures of muscle strength and performance. [ABSTRACT FROM AUTHOR]

Objective: Both grip strength and gait speed can be used as markers of muscle function, however, no previous study has examined them in the same population with respect to risk of falls. Methods: In this prospective cohort study, utilising data from the ASPirin in Reducing Events in the Elderly (ASPREE) trial and ASPREE-Fracture substudy, we analysed the association of grip strength and gait speed and serious falls in healthy older adults. Grip strength was measured using a handheld dynamometer and gait speed from 3-metre timed walks. Serious falls were confined to those involving hospital presentation. Cox regression was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for associations with falls. Results: Over an average of 4.0±1.3 years, amongst 16,445 participants, 1,533 had at least one serious fall. After adjustment for age, sex, physical activity, body mass index, Short Form 12 (state of health), chronic kidney disease, polypharmacy and aspirin, each standard deviation (SD) lower grip strength was associated with 27% (HR 1.27, 95% CI 1.17–1.38) higher risk of falls. The results remained the same for males and females. There was a dose-response relationship in the association between grip strength and falls risk. The higher risk of falls was observed in males in all body mass index (BMI) categories, but only in obese females. The association between gait speed and falls risk was weaker than the association between grip strength and falls risk. Conclusions: All males and only obese females with low grip strength appear to be at the greatest risk of serious falls. These findings may assist in early identification of falls. [ABSTRACT FROM AUTHOR]

Objective There is increasing evidence for the involvement of vascular disease in the pathogenesis of knee OA. Popliteal artery wall thickness can be used as a surrogate marker of atherosclerosis. We examined the association between popliteal artery wall thickness and knee cartilage volume in individuals with symptomatic knee OA. Methods This prospective cohort study analysed 176 participants from a randomized placebo-controlled trial examining the effect of atorvastatin on structural progression in knee OA. The participants underwent MRI of the study knee at baseline and 2-year follow-up. Popliteal artery wall thickness and tibial cartilage volume were measured from MRI using validated methods. The top quartile of the rate of tibial cartilage volume loss was defined as rapid progression. Results At baseline, every 10% increase in popliteal artery wall thickness was associated with 120.8 mm3 (95% CI 5.4, 236.2, P  = 0.04) lower of medial tibial cartilage volume and 151.9 mm3 (95% CI 12.1, 291.7, P  = 0.03) lower of lateral tibial cartilage volume. Longitudinally, for every 10% increase in popliteal artery wall thickness, the annual rate of medial tibial cartilage volume loss was increased by 1.14% (95% CI 0.09%, 2.20%, P  = 0.03), and there was a 2.28-fold (95% CI 1.07, 4.83, P  = 0.03) risk of rapid progression of medial tibial cartilage loss, adjusted for age, sex, BMI, tibial bone area, smoking, vigorous physical activity, and intervention group allocation. Conclusion The findings support a role for vascular pathology in the progression of knee OA. Targeting atherosclerosis has the potential to improve outcomes in knee OA. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Impaired cerebral blood flow has been associated with an increased risk of falls. Mean arterial pressure (MAP) and variability in MAP have been reported to affect cerebral blood flow but their relationships to the risk of falls have not previously been reported.Methods: Utilising data from the Aspirin in Reducing Events in the Elderly trial participants, we estimated MAP and variability in MAP, defined as within-individual SD of MAP from baseline and first 2 annual visits. The relationship with MAP was studied in 16 703 participants amongst whom 1539 falls were recorded over 7.3 years. Variability in MAP was studied in 14 818 of these participants who experienced 974 falls over 4.1 years. Falls were confined to those involving hospital presentation. Cox regression was used to calculate hazard ratio and 95% CI for associations with falls.Results: Long-term variability in MAP was not associated with falls except amongst frail or prefrail participants using antihypertensive medications. Within this group each 5 mm Hg increase in long-term variability in MAP increased the risk of falls by 16% (hazard ratio, 1.16 [95% CI, 1.02-1.33]). Amongst the antihypertensive drugs studied, beta-blocker monotherapy (hazard ratio, 1.93 [95% CI, 1.17-3.18]) was associated with an increased risk of falls compared with calcium channel blockers.Conclusions: Higher levels of long-term variability in MAP increase the risk of serious falls in older frail and prefrail individuals taking antihypertensive medications. The observation that the relationship was limited to frail and prefrail individuals might explain some of the variability of previous studies linking blood pressure indices and falls. [ABSTRACT FROM AUTHOR]

We examined the effect of person‐related factors on capacity to obtain needed healthcare for non‐COVID‐19 health conditions/disabilities under COVID‐19 restrictions. This was an anonymous online survey of Australian residents ≥18 years (3rd April to 2nd May 2020). We determined the ability to obtain care needed for non‐COVID‐19 health conditions/disabilities, experience of COVID‐19, COVID‐19 restrictions and sociodemographic characteristics using study‐specific questions; and clinically significant depressive and anxiety symptoms using Patient Health Questionnaire 9 and Generalised Anxiety Disorder Scale 7 respectively. We calculated the population attributable fraction (PAF) to determine the proportion of worse access to non‐COVID‐19 health/disability care attributable to independent risk factors. 13,829 (91.5%) participants had complete data. 6,712 (46.4%) identified a need for healthcare/disability services (<45 years 42.1%, ≥45 years 50.3%). 31.6% aged <45 years and 24.3% aged ≥45 years reported worse access to health/disability care than experienced prior to the pandemic. In those aged <45 years the PAF was highest for depressive symptoms (21.4%; 95% CI 12.6%–29.3%) and anxiety (PAF 19.9%, 12.3%–26.9%). with a PAF of 49.6% (40.1%–57.6%) if any one of the following was being experienced: doing unpaid work; being a student; depressive symptoms; symptoms of anxiety; experiencing high adverse impact of COVID‐19 restrictions. In those ≥45 years, PAF was highest for having depressive symptoms (PAF 20.9%, 16.6–24.8) with a PAF of 44.1% (36.0%–51.2%) if any one of the following was being experienced: depressive symptoms; symptoms of anxiety; doing unpaid work; living alone; being in lowest socioeconomic quintile; main source of income from government benefits; any personal experience of COVID‐19. The identified risk factors, which include many that characterise those with worse health outcomes generally, explained 44%–50% of worse access to necessary health/disability care. These data have the potential to inform targeted strategies aimed at reducing a post‐pandemic escalation of poor health outcomes, especially in vulnerable populations. [ABSTRACT FROM AUTHOR]

Objective: To determine whether atorvastatin slows tibial cartilage volume loss in patients with symptomatic knee osteoarthritis (OA) in a multicenter, randomized, double‐blind, placebo‐controlled trial. Methods: Participants ages 40–70 years were randomized to receive oral atorvastatin (40 mg once daily) (n = 151) or matching placebo (n = 153). The primary end point was annual percentage change in tibial cartilage volume over 2 years, assessed using magnetic resonance imaging (MRI). The prespecified secondary end points were progression of cartilage defects and bone marrow lesions over 2 years, which were assessed using MRI and change in Western Ontario and McMaster Universities Osteoarthritis (WOMAC) Index pain, stiffness, and function scores. Results: A total of 248 of 304 participants (81.6%) completed the trial (mean age 55.7 years; 55.6% women). The annual change in tibial cartilage volume differed minimally between the atorvastatin and placebo groups (mean change –1.66% versus –2.17%, between‐group difference 0.50% [95% confidence interval (95% CI) –0.17%, 1.17%]). There were no significant differences in the progression of cartilage defects (odds ratio [OR] 0.86 [95% CI 0.52, 1.41]) or progression of bone marrow lesions (OR 1.00 [95% CI 0.62, 1.63]). Moreover, there were no significant differences in change in WOMAC pain, stiffness, or function scores over 2 years between the atorvastatin and placebo groups (mean change in pain score –36.0 versus –29.5, adjusted difference –2.7 [95% CI –27.1, 21.7]; mean change in stiffness score –14.2 versus –11.8, adjusted difference –0.2 [95% CI –12.2, 11.8]; mean change in function score –89.4 versus –87.5, adjusted difference 0.3 [95% CI –83.1, 83.6]). The incidence of adverse events (AEs) was similar between the atorvastatin and placebo groups (57 [37.7%] versus 52 [34.0%] experiencing AEs). Conclusion: Treatment with oral atorvastatin (40 mg once daily), compared to placebo, did not significantly reduce cartilage volume loss over 2 years in patients with symptomatic knee OA. These findings do not support the use of atorvastatin for the treatment of knee OA. [ABSTRACT FROM AUTHOR]

Background: Back and lower limb pain have a major impact on physical function and quality of life. While obesity is a modifiable risk factor for musculoskeletal pain, the role of adiposity is less clear. This systematic review aimed to examine the relationship between both adiposity and its distribution and back and lower limb pain. Methods: A systematic search of electronic databases was conducted to identify studies that examined the association between anthropometric and/or direct measures of adiposity and site specific musculoskeletal pain. Risk of bias was assessed and a best evidence synthesis was performed. Results: A total of 56 studies were identified which examined 4 pain regions, including the lower back (36 studies), hip (two studies), knee (13 studies) and foot (eight studies). 31(55%) studies were assessed as having low to moderate risk of bias. 17(30%) studies were cohort in design. The best evidence synthesis provided evidence of a relationship between central adiposity and low back and knee pain, but not hip or foot pain. There was also evidence of a longitudinal relationship between adiposity and the presence of back, knee and foot pain, as well as incident and increasing foot pain. Conclusions: This systematic review provides evidence of an association between both body fat and its central distribution and low back and knee pain, and a longitudinal relationship between adiposity and back, knee and foot pain. These results highlight the potential for targeting adiposity in the development of novel treatments at these sites. [ABSTRACT FROM AUTHOR]

Objective: To determine the prevalence of neuropathic-like pain (NP) and pain sensitization (PS) defined by self-report questionnaires in knee and hip osteoarthritis, and whether prevalence is potentially explained by disease-severity or affected joint.Design: MEDLINE, EMBASE, CINAHL were systematically searched (1990-April 2020) for studies describing the prevalence of NP and PS in knee and hip osteoarthritis using self-report questionnaires. Random-effects meta-analysis was performed. Statistical heterogeneity between studies and sub-groups (affected joint and population source as a proxy for disease severity) was assessed (I2 statistic and the Chi-squared test).Results: From 2,706 non-duplicated references, 39 studies were included (2011-2020). Thirty-six studies reported on knee pain and six on hip pain. For knee osteoarthritis, the pooled prevalence of NP was: using PainDETECT, possible NP(score ≥13) 40% (95%CI 32-48%); probable NP(score >18) 20% (95%CI 15-24%); using Self-Report Leeds Assessment of Neuropathic Symptoms and Signs, 32% (95%CI 26-38%); using Douleur Neuropathique (DN4) 41% (95% CI 24-59%). The prevalence of PS using Central Sensitization Inventory (CSI) was 36% (95% CI 12-59%). For hip osteoarthritis, the pooled prevalence of NP was: using PainDETECT, possible NP 29% (95%CI 22-37%%); probable NP 9% (95%CI 6-13%); using DN4 22% (95%CI 12-31%) in one study. The prevalence of possible NP pain was higher at the knee (40%) than the hip (29%) (difference 11% (95% CI 0-22%), P = 0.05).Conclusions: Using self-report questionnaire tools, NP was more prevalent in knee than hip osteoarthritis. The prevalence of NP in knee and hip osteoarthritis were similar for each joint regardless of study population source or tool used. Whether defining NP using self-report questionnaires enables more effective targeted therapy in osteoarthritis requires investigation. [ABSTRACT FROM AUTHOR]

Objective: To examine the risk of total knee arthroplasty (TKA) due to osteoarthritis associated with obesity defined by body mass index (BMI) or waist circumference (WC) and whether there is discordance between these measures in assessing this risk. Methods: 36,784 participants from the Melbourne Collaborative Cohort Study with BMI and WC measured at 1990–1994 were included. Obesity was defined by BMI (≥30 kg/m2) or WC (men ≥102cm, women ≥88cm). The incidence of TKA between January 2001 and December 2018 was determined by linking participant records to the National Joint Replacement Registry. Results: Over 15.4±4.8 years, 2,683 participants underwent TKA. There were 20.4% participants with BMI-defined obesity, 20.8% with WC-defined obesity, and 73.6% without obesity defined by either BMI or WC. Obesity was classified as non-obese (misclassified obesity) in 11.7% of participants if BMI or WC alone was used to define obesity. BMI-defined obesity (HR 2.69, 95%CI 2.48–2.92), WC-defined obesity (HR 2.28, 95%CI 2.10–2.48), and obesity defined by either BMI or WC (HR 2.53, 95%CI 2.33–2.74) were associated with an increased risk of TKA. Compared with those without obesity, participants with misclassified obesity had an increased risk of TKA (HR 2.06, 95%CI 1.85–2.30). 22.7% of TKA in the community can be attributable to BMI-defined obesity, and a further 3.3% of TKA can be identified if WC was also used to define obesity. Conclusions: Both BMI and WC should be used to identify obese individuals who are at risk of TKA for osteoarthritis and should be targeted for prevention and treatment. [ABSTRACT FROM AUTHOR]

Objective: There 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. 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. 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. Conclusions: Lumbar 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. [ABSTRACT FROM AUTHOR]

Background: Almost a third of those undergoing knee replacement for osteoarthritis have poor outcomes despite technically successful surgery. Preoperative neuropathic-like pain and/or pain sensitisation may increase the risk of pain following joint replacement.Objective: To examine whether preoperative neuropathic-like pain and pain sensitisation predicts pain, function and satisfaction following joint replacement for knee osteoarthritis.Design: Systematic review with meta-analysis.Methods: Medline, EMBASE and CINAHL were systematically searched until March 2020. Studies detecting neuropathic-like pain and/or sensitisation using self-report questionnaires prior to knee replacement for osteoarthritis, and relating this to post-operative outcomes were identified. Data extraction, risk of bias assessment and meta-analysis were performed, where appropriate.Results: Five manuscripts, including one preprint, examining six cohorts were included: four used painDETECT or modified painDETECT, one the Self-Report Leeds Assessment of Neuropathic Symptoms and Signs, and another the Central Sensitisation Inventory to identify preoperative characteristics. Three studies showed preoperative neuropathic-like pain or sensitisation was associated with more intense post-operative pain. All four studies examining the risk of significant pain after knee replacement suggested it was increased after >3 months. The only study examining patient satisfaction and function found reduced satisfaction, but no difference in function in those with preoperative sensitisation. Meta-analysis found the relative risk of increased pain following knee replacement in those with neuropathic-like pain (painDETECT ≥13) to be 2.05 (95% confidence intervals 1.51, 2.79).Conclusion: These results provide consistent but limited evidence that self-report tools detecting neuropathic-like pain and/or pain sensitisation, predict patients at higher risk of pain following knee replacement. [ABSTRACT FROM AUTHOR]

Objective To examine whether the presence of bulge sign or patellar tap was associated with frequent knee pain, progression of radiographic OA (ROA) and total knee replacement (TKR). Methods This study included 4344 Osteoarthritis Initiative participants examined at baseline for bulge sign and/or patellar tap. The clinical signs were categorized as no (none at baseline and 2 years), resolved (present at baseline only), developed (present at 2 years only) and persistent (present at both time points). Frequent knee pain and progression of ROA over 4 years and TKR over 6 years were assessed. Binary logistic regression was used to examine the associations. Results A total of 12.7% of participants had bulge sign only, 2.0% had patellar tap only and 3.3% had both. A positive baseline bulge sign was associated with an increased risk of frequent knee pain [OR 1.31 (95% CI 1.04, 1.64), P = 0.02] and TKR [OR 1.47 (95% CI 1.06, 2.05), P = 0.02]. Developed bulge sign was associated with an increased risk of frequent knee pain [OR 1.75 (95% CI 1.34, 2.29), P < 0.001] and progressive ROA [OR 1.67 (95% CI 1.11, 2.51), P = 0.01]. Persistent bulge sign was associated with an increased risk of frequent knee pain [OR 1.60 (95% CI 1.09, 2.35), P = 0.02], progressive ROA [OR 1.84 (95% CI 1.01, 3.33), P = 0.045] and TKR [OR 2.13 (95% CI 1.23, 3.68), P = 0.007]. Patellar tap was not examined for its association with joint outcomes due to its low prevalence. Conclusion The presence of bulge sign identifies individuals at increased risk of frequent knee pain, progression of ROA and TKR. This provides clinicians with a quick, simple, inexpensive method for identifying those at higher risk of progressive knee OA who should be targeted for therapy. [ABSTRACT FROM AUTHOR]

Objective To examine whether baseline knee joint effusion volume and the change in effusion volume over 1 year are associated with cartilage volume loss, progression of radiographic OA (ROA) over 4 years and risk of total knee replacement over 6 years. Methods This study included 4115 Osteoarthritis Initiative participants with knee joint effusion volume quantified by MRI at baseline. The change in effusion volume over 1 year was assessed. Cartilage volume loss and progression of ROA over 4 years were assessed using MRI and X-ray and total knee replacement over 6 years was assessed. Multiple linear regression and binary logistic regression were used for data analyses. Results Baseline knee effusion volume (per 5 ml) was positively associated with a loss of medial and lateral cartilage volume [regression coefficient 0.13%/year (95% CI 0.10, 0.17) and 0.13%/year (95% CI 0.10, 0.16), respectively, both P < 0.001], progression of ROA [odds ratio (OR) 1.28 (95% CI 1.20, 1.37), P < 0.001], and risk of knee replacement [OR 1.12 (95% CI 1.05, 1.20), P = 0.001]. A 5 ml increase in knee effusion volume over 1 year was positively associated with medial cartilage volume loss [regression coefficient 0.09%/year (95% CI 0.04, 0.15), P = 0.001], progression of ROA [OR 1.21 (95% CI 1.11, 1.33), P < 0.001] and risk of knee replacement [OR 1.24 (95% CI 1.12, 1.37), P < 0.001]. Conclusions Knee joint effusion volume assessed from MRI provides a continuous and sensitive measure that was associated with cartilage volume loss, progression of ROA and risk of total knee replacement. It may provide a method to identify individuals with an inflammatory OA phenotype who are at higher risk of disease progression. [ABSTRACT FROM AUTHOR]

Abstract Objective Diabetes (DM) and osteoarthritis (OA) are two common co-existing chronic conditions. However, whether this is due to shared risk factors or may differ between joints is unclear. We performed a systematic review to determine whether abnormal glucose metabolism is a risk factor for knee, hip and hand OA, separately, independent of age and obesity. Methods A systematic search of Ovid Medline and EMBASE was performed from inception until October 2016 to identify studies relating glucose metabolism to osteoarthritis-related outcomes. Studies were included if they related DM and OA and the knee, hip, or hand were examined separately. In the structured synthesis, objective measures of DM and adjustment for age and obesity were also required. Results Of the 40 included studies, 28 examined the knee, nine the hip and 14 the hand. Five studies with a longitudinal component used objective measures of DM (blood glucose) and knee OA (radiography or joint replacement) and adjusted for age and obesity (21,299 participants). Of these, three found no association, one found a reduction in risk and one, which adjusted for the presence but not magnitude of obesity, found an increase in risk. Of the longitudinal studies examining the relationship between DM and OA that accounted for obesity, none provided evidence of an independent relationship between DM and hip (2 studies) or hand OA (1 study). Conclusion There is little evidence to suggest that impaired glucose metabolism is a risk factor, independent of obesity, for knee OA and no evidence that impaired glucose metabolism is an independent risk factor for hip or hand OA. [ABSTRACT FROM AUTHOR]

Objective: To examine the associations of female reproductive and hormonal factors with incidence of total knee arthroplasty (TKA) for osteoarthritis (OA), and to determine whether the associations differ according to overweight/obesity status. Methods: This study included 22,289 women in the Melbourne Collaborative Cohort Study. Data on age at menarche, pregnancy, parity, years of menstruation, oral contraceptive (OC) use, menopausal status, and hormone replacement therapy (HRT) were collected in 1990–1994. Incidence of TKA during 2001–2013 was determined by linking cohort records to the Australian Orthopaedic Association National Joint Replacement Registry. All analyses were adjusted for age, body mass index (BMI) at midlife, change in BMI (from early reproductive age to midlife), country of birth, physical activity, smoking, and education level. Results: Over the course of 12.7 years, 1,208 TKAs for OA were identified. Ever being pregnant was associated with increased risk of TKA (hazard ratio [HR] 1.32 [95% confidence interval (95% CI) 1.06–1.63]). Parity was positively associated with risk of TKA (P for trend = 0.003). OC users had increased risk of TKA compared with non‐users (for OC use of <5 years, HR 1.25 [95% CI 1.08–1.45]; for OC use of ≥5 years, HR 1.17 [95% CI 1.00–1.37]). A 1‐year increase in menstruation was associated with a 1% decrease in risk of TKA (HR 0.99 [95% CI 0.97–0.99]). These associations remained significant only in women of normal weight at early reproductive age. Current HRT users had increased risk of TKA compared with non‐users (HR 1.37 [95% CI 1.14–1.64]); the association was significant only in non‐obese women at midlife. Conclusion: Reproductive and hormonal factors were associated with risk of knee OA. These associations remained significant in women of normal weight at early reproductive age and in non‐obese women at midlife. Further work is needed to understand the complex effect of these factors on knee OA. [ABSTRACT FROM AUTHOR]