What effect have commissioners' policies for body mass index had on hip replacement surgery?: an interrupted time series analysis from the National Joint Registry for England.

BACKGROUND: Despite their widespread use, the impact of commissioners' policies for body mass index (BMI) for access to elective surgery is not clear. Policy use varies by locality, and there are concerns that these policies may worsen health inequalities. The aim of this study was to assess the impact of policies for BMI on access to hip replacement surgery in England. METHODS: A natural experimental study using interrupted time series and difference-in-differences analysis. We used National Joint Registry data for 480,364 patients who had primary hip replacement surgery in England between January 2009 and December 2019. Clinical commissioning group policies introduced before June 2018 to alter access to hip replacement for patients with overweight or obesity were considered the intervention. The main outcome measures were rate of surgery and patient demographics (BMI, index of multiple deprivation, independently funded surgery) over time. RESULTS: Commissioning localities which introduced a policy had higher surgery rates at baseline than those which did not. Rates of surgery fell after policy introduction, whereas rates rose in localities with no policy. 'Strict' policies mandating a BMI threshold for access to surgery were associated with the sharpest fall in rates (trend change of - 1.39 operations per 100,000 population aged 40 + per quarter-year, 95% confidence interval - 1.81 to - 0.97, P < 0.001). Localities with BMI policies have higher proportions of independently funded surgery and more affluent patients receiving surgery, indicating increasing health inequalities. Policies enforcing extra waiting time before surgery were associated with worsening mean pre-operative symptom scores and rising obesity. CONCLUSIONS: Commissioners and policymakers should be aware of the counterproductive effects of BMI policies on patient outcomes and inequalities. We recommend that BMI policies involving extra waiting time or mandatory BMI thresholds are no longer used to reduce access to hip replacement surgery.

Menopausal symptoms by HIV status and association with health-related quality of life among women in Zimbabwe: a cross-sectional study.

BACKGROUND: The scale-up of antiretroviral therapy programmes has resulted in increased life expectancy of people with HIV in Africa. Little is known of the menopausal experiences of African women, including those living with HIV. We aimed to determine the prevalence and severity of self-reported menopause symptoms in women at different stages of menopause transition, by HIV status, and evaluate how symptoms are related to health-related quality of life (HRQoL). We further sought to understand factors associated with menopause symptoms. METHODS: A cross-sectional study recruited women resident in Harare, Zimbabwe, sampled by age group (40-44/45-49/50-54/55-60 years) and HIV status. Women recruited from public-sector HIV clinics identified two similarly aged female friends (irrespective of HIV status) with phone access. Socio-demographic and medical details were recorded and women staged as pre-, peri- or post-menopause. The Menopausal Rating Scale II (MRS), which classified symptom severity, was compared between those with and without HIV. Linear and logistic regression determined factors associated with menopause symptoms, and associations between symptoms and HRQoL. RESULTS: The 378 women recruited (193[51.1%] with HIV), had a mean (SD) age of 49.3 (5.7) years; 173 (45.8%), 51 (13.5%) and 154 (40.7%) were pre-, peri and post-menopausal respectively. Women with HIV reported more moderate (24.9% vs. 18.1%) and severe (9.7% vs. 2.6%) menopause symptoms than women without HIV. Peri-menopausal women with HIV reported higher MRS scores than those pre- and post-menopausal, whereas in HIV negative women menopausal stage was not associated with MRS score (interaction p-value = 0.014). With increasing severity of menopause symptoms, lower mean HRQoL scores were observed. HIV (OR 2.02[95% CI 1.28, 3.21]), mood disorders (8.80[2.77, 28.0]), ≥ 2 falls/year (4.29[1.18, 15.6]), early menarche (2.33[1.22, 4.48]), alcohol consumption (2.16[1.01, 4.62]), food insecurity (1.93[1.14, 3.26]) and unemployment (1.56[0.99, 2.46]), were all associated with moderate/severe menopause symptoms. No woman reported use of menopausal hormone therapy. CONCLUSIONS: Menopausal symptoms are common and negatively impact HRQoL. HIV infection is associated with more severe menopause symptoms, as are several modifiable factors, including unemployment, alcohol consumption, and food insecurity. Findings highlight an unmet health need in ageing women in Zimbabwean, especially among those living with HIV.

The influence of mode of anaesthesia on perioperative outcomes in people with hip fracture: a prospective cohort study from the National Hip Fracture Database for England, Wales and Northern Ireland.

BACKGROUND: Delirium is common after hip fracture surgery, affecting up to 50% of patients. The incidence of delirium may be influenced by mode and conduct of anaesthesia. We examined the effect of spinal anaesthesia (with and without sedation) compared with general anaesthesia on early outcomes following hip fracture surgery, including delirium. METHODS: We used prospective data on 107,028 patients (2018 to 2019) from the National Hip Fracture Database, which records all hip fractures in patients aged 60 years and over in England, Wales and Northern Ireland. Patients were grouped by anaesthesia: general (58,727; 55%), spinal without sedation (31,484; 29%), and spinal with sedation (16,817; 16%). Outcomes (4AT score on post-operative delirium screening; mobilisation day one post-operatively; length of hospital stay; discharge destination; 30-day mortality) were compared between anaesthetic groups using multivariable logistic and linear regression models. RESULTS: Compared with general anaesthesia, spinal anaesthesia without sedation (but not spinal with sedation) was associated with a significantly reduced risk of delirium (odds ratio (OR)=0.95, 95% confidence interval (CI)=0.92-0.98), increased likelihood of day one mobilisation (OR=1.06, CI=1.02-1.10) and return to original residence (OR=1.04, CI=1.00-1.07). Spinal without sedation (p<0.001) and spinal with sedation (p=0.001) were both associated with shorter hospital stays compared with general anaesthesia. No differences in mortality were observed between anaesthetic groups. CONCLUSIONS: Spinal and general anaesthesia achieve similar outcomes for patients with hip fracture. However, this equivalence appears to reflect improved perioperative outcomes (including a reduced risk of delirium, increased likelihood of mobilisation day one post-operatively, shorter length of hospital stay and improved likelihood of returning to previous residence on discharge) among the sub-set of patients who received spinal anaesthesia without sedation. The role and effect of sedation should be studied in future trials of hip fracture patients undergoing spinal anaesthesia.

Incidence and number of fragility fractures of the hip in South Africa: estimated projections from 2020 to 2050.

Sub-Saharan Africa is undergoing rapid population ageing and better understanding of the burden of musculoskeletal conditions is needed. We have estimated a large increase in the burden of hip fractures for South Africa over the coming decades. These findings should support preparation of hip fracture services to meet this demand. INTRODUCTION: A better understanding of the burden of fragility fractures in sub-Saharan Africa is needed to inform healthcare planning. We aimed to use recent hip fracture incidence data from South Africa (SA) to estimate the future burden of hip fracture for the country over the next three decades. METHODS: Hip fracture incidence data within the Gauteng, KwaZulu-Natal and Western Cape provinces of SA were obtained from patients aged ≥ 40 years with a radiograph-confirmed hip fracture in one of 94 included hospitals. Age-, sex- and ethnicity-specific incidence rates were generated using the 2011 SA census population for the study areas. Incidence rates were standardised to United Nations (UN) population projections, for the years 2020, 2030, 2040 and 2050, and absolute numbers of hip fractures derived. RESULTS: The 2767 hip fracture patients studied had mean (SD) age 73.7 (12.7) years; 69% were female. Estimated age- and ethnicity-standardised incidence rates (per 100,000 person-years) for the overall SA population in 2020 were 81.2 for females and 43.1 for males. Overall projected incidence rates were discernibly higher by the year 2040 and increased further by the year 2050 (109.0 and 54.1 for females and males, respectively). Estimates of the overall annual number of hip fractures for SA increased from approximately 11,000 in 2020 to approximately 26,400 by 2050. CONCLUSION: The hip fracture burden for SA is expected to more than double over the next 30 years. Significant investment in fracture prevention services and inpatient fracture care is likely to be needed to meet this demand.

Predictors of returning home after hip fracture: a prospective cohort study using the UK National Hip Fracture Database (NHFD).

INTRODUCTION: our objective was to describe trends in returning home after hospitalisation for hip fracture and identify predictive factors of this important patient-focussed outcome. METHODS: a cohort of hip fracture patients from England and Wales (2018-2019) resident in their own home pre-admission were analysed to identify patient and service factors associated with returning home after hospital discharge, and with living in their own home at 120 days. Geographical variation was also analysed. RESULTS: analysis of returning home at discharge included 87,797 patients; 57,104 (65%) were discharged home. Patient factors associated with lower likelihood of discharge home included cognitive impairment (odds ratio (OR) 0.60 [95% CI: 0.57, 0.62]), malnutrition (OR 0.81 [0.76, 0.86]), being at risk of malnutrition (OR 0.81 [0.78, 0.85]) and experiencing delay to surgery due to reversal of anti-coagulant medication (OR 0.84 [0.77, 0.92]). Corresponding service factors included surgery delay due to hospital logistical reasons (OR 0.91 [0.87, 0.95]) and early morning admission between 4:00 and 7:59 am (OR 0.83 [0.78, 0.89]). Nerve block prior to arrival at the operating theatre was associated with higher likelihood of discharge home (OR 1.07 [1.03, 1.11]). Most of these associations were stronger when analysing the outcome 'living in their own home at 120 days', in which two out of 11 geographic regions were found to have significantly more patients returning home. CONCLUSION: we identify numerous modifiable factors associated with short-term and medium-term return to own home after hip fracture, in addition to significant geographical variation. These findings should support improvements to care and inform future research.

Higher prevalence of non-skeletal comorbidity related to X-linked hypophosphataemia: a UK parallel cohort study using CPRD.

OBJECTIVES: X-Linked hypophosphataemic rickets (XLH) is a rare multi-systemic disease of mineral homeostasis that has a prominent skeletal phenotype. The aim of this study was to describe additional comorbidities in XLH patients compared with general population controls. METHODS: The Clinical Practice Research Datalink (CPRD) GOLD was used to identify a cohort of XLH patients (1995-2016), along with a non-XLH cohort matched (1 : 4) on age, sex and GP practice. Using the CALIBER portal, phenotyping algorithms were used to identify the first diagnosis (and associated age) of 273 comorbid conditions during patient follow-up. Fifteen major disease categories were used and the proportion of patients having ≥1 diagnosis was compared between cohorts for each category and condition. Main analyses were repeated according to the Index of Multiple Deprivation (IMD). RESULTS: There were 64 and 256 patients in the XLH and non-XLH cohorts, respectively. There was increased prevalence of endocrine [OR 3.46 (95% CI: 1.44, 8.31)] and neurological [OR 3.01 (95% CI: 1.41, 6.44)] disorders among XLH patients. Across all specific comorbidities, four were at least twice as likely to be present in XLH cases, but only depression met the Bonferroni threshold: OR 2.95 (95% CI: 1.47, 5.92). Distribution of IMD among XLH cases indicated greater deprivation than the general population. CONCLUSION: We describe a higher risk of mental illness in XLH patients compared with matched controls, and greater than expected deprivation. These findings may have implications for clinical practice guidelines and decisions around health and social care provision for these patients.

Impact of TNF inhibitor therapy on joint replacement rates in rheumatoid arthritis: a matched cohort analysis of BSRBR-RA UK registry data.

OBJECTIVES: Previous ecological data suggest a decline in the need for joint replacements in RA patients following the introduction of TNF inhibitor (TNFi) therapy, although patient-level data are lacking. Our primary aim was to estimate the association between TNFi use and subsequent incidence of total hip replacement (THR) and total knee replacement. METHODS: A propensity score matched cohort was analysed using the British Society for Rheumatology Biologics Registry (2001-2016) for RA data. Propensity score estimates were used to match TNFi users to similar conventional synthetic DMARD users (with replacement) using a 1:1 ratio. Weighted multivariable Cox regression was used to estimate the impact of TNFi on study outcomes. Effect modification by baseline age and disease severity were investigated. Joint replacement at other sites was also analysed. An instrumental variable sensitivity analysis was also performed. RESULTS: The matched analysis contained a total of 19 116 patient records. Overall, there was no significant association between TNFi use vs conventional synthetic DMARD on rates of THR (hazard ratios = 0.86 [95% CI: 0.60, 1.22]) although there was significant effect modification by age (P < 0.001). TNFi was associated with a reduction in THR among those >60 years old (hazard ratio = 0.60 [CI: 0.41, 0.87]) but not in younger patients. No significant associations were found for total knee replacement or other joint replacement. CONCLUSION: Overall, no association was found between the use of TNFi and subsequent incidence of joint replacement. However, TNFi was associated with a 40% relative reduction in THR rates among older patients.

Incidence of hip and knee replacement in patients with rheumatoid arthritis following the introduction of biological DMARDs: an interrupted time-series analysis using nationwide Danish healthcare registers.

OBJECTIVES: To study the impact of the introduction of biological disease-modifying anti-rheumatic drugs (bDMARDs) and associated rheumatoid arthritis (RA) management guidelines on the incidence of total hip (THR) and knee replacements (TKR) in Denmark. METHODS: Nationwide register-based cohort and interrupted time-series analysis. Patients with incident RA between 1996 and 2011 were identified in the Danish National Patient Register. Patients with RA were matched on age, sex and municipality with up to 10 general population comparators (GPCs). Standardised 5-year incidence rates of THR and TKR per 1000 person-years were calculated for patients with RA and GPCs in 6-month periods. Levels and trends in the pre-bDMARD (1996-2001) were compared with the bDMARD era (2003-2016) using segmented linear regression interrupted by a 1-year lag period (2002). RESULTS: We identified 30 404 patients with incident RA and 297 916 GPCs. In 1996, the incidence rate of THR and TKR was 8.72 and 5.87, respectively, among patients with RA, and 2.89 and 0.42 in GPCs. From 1996 to 2016, the incidence rate of THR decreased among patients with RA, but increased among GPCs. Among patients with RA, the incidence rate of TKR increased from 1996 to 2001, but started to decrease from 2003 and throughout the bDMARD era. The incidence of TKR increased among GPCs from 1996 to 2016. CONCLUSION: We report that the incidence rate of THR and TKR was 3-fold and 14-fold higher, respectively among patients with RA compared with GPCs in 1996. In patients with RA, introduction of bDMARDs was associated with a decreasing incidence rate of TKR, whereas the incidence of THR had started to decrease before bDMARD introduction.

Clinical effectiveness of orthogeriatric and fracture liaison service models of care for hip fracture patients: population-based longitudinal study.

OBJECTIVES: to evaluate orthogeriatric and nurse-led fracture liaison service (FLS) models of post-hip fracture care in terms of impact on mortality (30 days and 1 year) and second hip fracture (2 years). SETTING: Hospital Episode Statistics database linked to Office for National Statistics mortality records for 11 acute hospitals in a region of England. POPULATION: patients aged over 60 years admitted for a primary hip fracture from 2003 to 2013. METHODS: each hospital was analysed separately and acted as its own control in a before-after time-series design in which the appointment of an orthogeriatrician or set-up/expansion of an FLS was evaluated. Multivariable Cox regression (mortality) and competing risk survival models (second hip fracture) were used. Fixed effects meta-analysis was used to pool estimates of impact for interventions of the same type. RESULTS: of 33,152 primary hip fracture patients, 1,288 sustained a second hip fracture within 2 years (age and sex standardised proportion of 4.2%). 3,033 primary hip fracture patients died within 30 days and 9,662 died within 1 year (age and sex standardised proportion of 9.5% and 29.8%, respectively). The estimated impact of introducing an orthogeriatrician on 30-day and 1-year mortality was hazard ratio (HR) = 0.73 (95% CI: 0.65-0.82) and HR = 0.81 (CI: 0.75-0.87), respectively. Following an FLS, these associations were as follows: HR = 0.80 (95% CI: 0.71-0.91) and HR = 0.84 (0.77-0.93). There was no significant impact on time to second hip fracture. CONCLUSIONS: the introduction and/or expansion of orthogeriatric and FLS models of post-hip fracture care has a beneficial effect on subsequent mortality. No evidence for a reduction in second hip fracture rate was found.

Risk Factors and 120-Day Functional Outcomes of Delirium After Hip Fracture Surgery: A Prospective Cohort Study Using the UK National Hip Fracture Database (NHFD).

OBJECTIVES: To identify risk factors of postoperative delirium among hip fracture patients with normal preoperative cognition, and examine associations with returning home or recovery of mobility. DESIGN: Prospective cohort study. SETTING AND PARTICIPANTS: We used the National Hip Fracture Database (NHFD) to identify patients presenting with hip fracture in England (2018-2019), but excluded those with abnormal cognition [abbreviated mental test score (AMTS) < 8] on presentation. METHODS: We examined the results of routine delirium screening performed using the 4 A's Test (4AT), to assess alertness, attention, acute change, and orientation in a 4-item mental test. Associations between 4AT score and return home or to outdoor mobility at 120 days were estimated, and risk factors identified for abnormal 4AT scores: (1) 4AT ≥4 suggesting delirium and (2) 4AT = 1-3 being an intermediate score not excluding delirium. RESULTS: Overall, 63,502 patients (63%) had a preoperative AMTS ≥8, in whom a postoperative 4AT score ≥4 suggestive of delirium was seen in 4454 (7%). These patients were less likely to return home [odds ratio (OR), 0.46; 95% CI, 0.38-0.55] or regain outdoor mobility (OR, 0.63; 95% CI, 0.53-0.75) by 120 days. Multiple factors including any deficit in preoperative AMTS and malnutrition were associated with higher risk of 4AT ≥4, while use of preoperative nerve blocks was associated with lower risk (OR, 0.88; 95% CI, 0.81-0.95). Poorer outcomes were also seen in 12,042 (19%) patients with 4AT = 1-3; additional risk factors associated with this score included socioeconomic deprivation and surgical procedure types that were not compliant with National Institute of Health and Care Excellence guidance. CONCLUSION AND IMPLICATIONS: Delirium after hip fracture surgery significantly reduces the likelihood of returning home or to outdoor mobility. Our findings underline the importance of measures to prevent postoperative delirium, and aid the identification of high-risk patients for whom delirium prevention might potentially improve outcomes.

Psychological/social factors associated with transfer readiness in young people with juvenile idiopathic arthritis.

The aim of this study is to investigate the relationships between psychological/social factors and transfer readiness from paediatric to adult rheumatology services in pre- and post-transfer young people (YP) with juvenile idiopathic arthritis (JIA). Participants completed questionnaires measuring a broad range of psychological/social factors (generalised anxiety, pain-specific anxiety, pain-related thoughts, depression, prosocial behaviours, problem behaviours, arthritis-related quality of life (QoL), social support, family functioning) and transfer readiness (transfer-related knowledge and skills, health-related self-efficacy). JIA disease activity was measured on the same day as the questionnaires. This study received all relevant ethical and regulatory approvals, and informed consent was received from or on behalf of all participants. In total, 40 pre-transfer YP with JIA aged 10-16 years (M = 13.54 years, 26 females) and their parents/guardians participated at Sheffield Children's NHS Foundation Trust, and 40 post-transfer YP with JIA aged 16-24 years (M = 20.16 years, 26 females) participated at Sheffield Teaching Hospitals NHS Foundation Trust. For both pre- and post-transfer YP, greater transfer readiness was associated with lower generalised anxiety levels, lower pain-specific anxiety levels, fewer pain-related thoughts, lower depression levels, fewer problem behaviours, better arthritis-related QoL, better social support, and better family functioning. Greater transfer readiness was also associated with less JIA disease activity for post-transfer YP only. A broad range of psychological/social factors were associated with transfer readiness in pre- and post-transfer YP with JIA. This highlights the importance of assessing and addressing YP's psychological/social well-being during their transition to adult services. Key Points • A wide range of psychological and social factors may be associated with how ready young people with juvenile idiopathic arthritis feel to move from paediatric to adult rheumatology services. • Transition outcomes may be improved by comprehensively assessing and addressing young people's psychological and social well-being.

What effect have NHS commissioners' policies for body mass index had on access to knee replacement surgery in England?: An interrupted time series analysis from the National Joint Registry.

OBJECTIVE: To assess the impact of local commissioners' policies for body mass index on access to knee replacement surgery in England. METHODS: A Natural Experimental Study using interrupted time series and difference-in-differences analysis. We used National Joint Registry for England data linked to the 2015 Index of Multiple Deprivation for 481,555 patients who had primary knee replacement surgery in England between January 2009 and December 2019. Clinical Commissioning Group policies introduced before June 2018 to alter access to knee replacement for patients who were overweight or obese were considered the intervention. The main outcome measures were rate per 100,000 of primary knee replacement surgery and patient demographics (body mass index, Index of Multiple Deprivation, independently-funded surgery) over time. RESULTS: Rates of surgery had a sustained fall after the introduction of a policy (trend change of -0.98 operations per 100,000 population aged 40+, 95% confidence interval -1.22 to -0.74, P<0.001), whereas rates increased in localities with no policy introduction. At three years after introduction, there were 10.5 per 100,000 population fewer operations per quarter aged 40+ compared to the counterfactual, representing a fall of 14.1% from the rate expected had there been no change in trend. There was no dose response effect with policy severity. Rates of surgery fell in all patient groups, including non-obese patients following policy introduction. The proportion of independently-funded operations increased after policy introduction, as did the measure of socioeconomic deprivation of patients. CONCLUSIONS: Body mass index policy introduction was associated with decreases in the rates of knee replacement surgery across localities that introduced policies. This affected all patient groups, not just obese patients at whom the policies were targeted. Changes in patient demographics seen after policy introduction suggest these policies may increase health inequalities and further qualitative research is needed to understand their implementation and impact.

Descriptive epidemiology of hip and knee replacement in rheumatoid arthritis: An analysis of UK electronic medical records.

OBJECTIVE: To provide descriptive data on rates of total hip replacement (THR) and total knee replacement (TKR) within a large RA cohort and describe variation in risk. METHODS: Incident RA patients (1995 to 2014) were identified from the Clinical Practice Research Datalink (CPRD). First subsequent occurrence of THR and TKR were identified (analysed separately) and incidence rates calculated, stratified by sex, age, BMI, geographic region, and quintiles of the index of multiple deprivation (IMD) score. RESULTS: There were 27,607 RA patients included, with a total of 1,028 THRs (mean age at surgery: 68.4 years) and 1,366 TKRs (mean age at surgery: 67.6 years), at an overall incidence rate per 1,000 person-years (PYs) [95% CI] of 6.38 [6.00-6.78] and 8.57 [8.12-9.04], respectively. TKR incidence was similar by gender but THR rates were higher in females than males. Rates of TKR but not THR rose according to BMI. An increasing trend was observed in rates of both outcomes according to age (although not ≥75) but of decreasing rates according to socio-economic deprivation. There was some evidence for regional variation in TKR. The 10-year cumulative incidence was 5.2% [4.9, 5.6] and 7.0% [6.6, 7.4] for THR and TKR, respectively. CONCLUSION: We provide generalizable estimates of THR and TKR incidence in the UK RA patient population and note variation across several key variables. Increased BMI was associated with a large increase in TKR but not THR incidence. Increased deprivation was associated with a downward trend in rates of THR and TKR.

Prevalence and Mortality of Individuals With X-Linked Hypophosphatemia: A United Kingdom Real-World Data Analysis.

BACKGROUND: X-linked hypophosphatemia (XLH) is a rare multisystemic disease with a prominent musculoskeletal phenotype. We aim here to improve understanding of the prevalence of XLH across the life course and of overall survival among people with XLH. METHODS: This was a population-based cohort study using a large primary care database in the United Kingdom (UK) from 1995 to 2016. XLH cases were matched by age, gender, and practice to up to 4 controls. Trends in prevalence over the study period were estimated (stratified by age) and survival among cases was compared with that of controls. FINDINGS: From 522 potential cases, 122 (23.4%) were scored as at least possible XLH, while 62 (11.9%) were classified as highly likely or likely (conservative definition). In main analyses, prevalence (95% CI) increased from 3.1 (1.5-6.7) per million in 1995-1999 to 14.0 (10.8-18.1) per million in 2012-2016. Corresponding estimates using the conservative definition were 3.0 (1.4-6.5) to 8.1 (5.8-11.4). Nine (7.4%) of the possible cases died during follow-up, at median age of 64 years. Fourteen (2.9%) of the controls died at median age of 72.5 years. Mortality was significantly increased in those with possible XLH compared with controls (hazard ratio [HR] 2.93; 95% CI, 1.24-6.91). Likewise, among those with likely or highly likely XLH (HR 6.65; 1.44-30.72). CONCLUSIONS: We provide conservative estimates of the prevalence of XLH in children and adults within the UK. There was an unexpected increase in mortality in later life, which may have implications for other fibroblast growth factor 23-related disorders.

Reduction in Upper Limb Joint Surgery Among Rheumatoid Arthritis Patients: An Interrupted Time-Series Analysis Using Danish Health Care Registers.

OBJECTIVE: Joint replacement surgery is a proxy of severe joint damage in rheumatoid arthritis (RA). The aim of this study was to assess the impact of the introduction of biologic disease-modifying antirheumatic drugs (bDMARDs) on the incidence rate (IR) of upper limb joint replacements among newly diagnosed RA patients. METHODS: Using the Danish National Patient Register, patients with incident RA from 1996-2012 were identified. Each patient was matched on age, sex, and municipality, with up to 10 general population controls. The age- and sex-standardized 5-year IR per 1,000 person-years of a composite outcome of any first joint replacement of the finger, wrist, elbow, or shoulder was calculated, and an interrupted time-series analysis was undertaken to investigate trends and changes of the IR in the pre-bDMARD (1996-2001) and the bDMARD eras (2003-2012), with a 1-year lag period in 2002. RESULTS: In total, 18,654 incident patients with RA were identified (mean age 57.6 years, 70.5% women). The IR of joint replacements among patients with RA was stable at 2.46 per 1,000 person-years (95% confidence interval [95% CI] 1.96, 2.96) from 1996 to 2001 but started to decrease from 2003 onwards (-0.08 per 1,000 person-years annually [95% CI -0.20, 0.02]). Compared with patients with RA, the IR among controls in 1996 was 1/17 and increased continuously throughout the study period. CONCLUSION: The IR of upper limb joint replacements started to decrease among patients with RA from 2002 onwards, whereas it increased among controls. Our results suggest an association between the introduction of bDMARDs and a lower need of joint replacements among patients with RA.

Sample size and power considerations for ordinary least squares interrupted time series analysis: a simulation study.

Interrupted time series (ITS) analysis is being increasingly used in epidemiology. Despite its growing popularity, there is a scarcity of guidance on power and sample size considerations within the ITS framework. Our aim of this study was to assess the statistical power to detect an intervention effect under various real-life ITS scenarios. ITS datasets were created using Monte Carlo simulations to generate cumulative incidence (outcome) values over time. We generated 1,000 datasets per scenario, varying the number of time points, average sample size per time point, average relative reduction post intervention, location of intervention in the time series, and reduction mediated via a 1) slope change and 2) step change. Performance measures included power and percentage bias. We found that sample size per time point had a large impact on power. Even in scenarios with 12 pre-intervention and 12 post-intervention time points with moderate intervention effect sizes, most analyses were underpowered if the sample size per time point was low. We conclude that various factors need to be collectively considered to ensure adequate power for an ITS study. We demonstrate a means of providing insight into underlying sample size requirements in ordinary least squares (OLS) ITS analysis of cumulative incidence measures, based on prespecified parameters and have developed Stata code to estimate this.

Oral bisphosphonate use and age-related macular degeneration: retrospective cohort and nested case-control study.

Our objective here was to determine whether oral bisphosphonate (BP) use is associated with the incidence of age-related macular degeneration (AMD). We performed a population-based study using electronic health records from UK primary care (Clinical Practice Research Datalink). A cohort of 13,974 hip fracture patients (1999-2013) was used to conduct (1) a propensity score-matched cohort analysis and (2) a nested case-control analysis. Hip fracture patients were aged ≥50 years without AMD diagnosis before hip fracture date or in the first year of follow-up. Among 6208 matched patients and during 22,142 person-years of follow-up, 57 (1.8%) and 42 (1.4%) AMD cases occurred in BP users and non-BP users, respectively. The survival analysis model did not provide significant evidence of a higher risk of AMD in BP users (subhazard ratio: 1.60; 95% confidence interval (CI): 0.95-2.72; P = 0.08), although there was a significant increased risk among BP users with high medication possession ratio (MPR) (top quartile) relative to non-BP users (odds ratio: 5.08, 95% CI: 3.11-8.30; P < 0.001, respectively). Overall, oral BP use was not associated with an increased risk of AMD in this cohort of hip fracture patients, although the risk increased significantly with higher MPR. More data are needed to confirm these findings.

The impact of different strategies to handle missing data on both precision and bias in a drug safety study: a multidatabase multinational population-based cohort study.

BACKGROUND: Missing data are often an issue in electronic medical records (EMRs) research. However, there are many ways that people deal with missing data in drug safety studies. AIM: To compare the risk estimates resulting from different strategies for the handling of missing data in the study of venous thromboembolism (VTE) risk associated with antiosteoporotic medications (AOM). METHODS: New users of AOM (alendronic acid, other bisphosphonates, strontium ranelate, selective estrogen receptor modulators, teriparatide, or denosumab) aged ≥50 years during 1998-2014 were identified in two Spanish (the Base de datos para la Investigación Farmacoepidemiológica en Atención Primaria [BIFAP] and EpiChron cohort) and one UK (Clinical Practice Research Datalink [CPRD]) EMR. Hazard ratios (HRs) according to AOM (with alendronic acid as reference) were calculated adjusting for VTE risk factors, body mass index (that was missing in 61% of patients included in the three databases), and smoking (that was missing in 23% of patients) in the year of AOM therapy initiation. HRs and standard errors obtained using cross-sectional multiple imputation (MI) (reference method) were compared to complete case (CC) analysis - using only patients with complete data - and longitudinal MI - adding to the cross-sectional MI model the body mass index/smoking values as recorded in the year before and after therapy initiation. RESULTS: Overall, 422/95,057 (0.4%), 19/12,688 (0.1%), and 2,051/161,202 (1.3%) VTE cases/participants were seen in BIFAP, EpiChron, and CPRD, respectively. HRs moved from 100.00% underestimation to 40.31% overestimation in CC compared with cross-sectional MI, while longitudinal MI methods provided similar risk estimates compared with cross-sectional MI. Precision for HR improved in cross-sectional MI versus CC by up to 160.28%, while longitudinal MI improved precision (compared with cross-sectional) only minimally (up to 0.80%). CONCLUSION: CC may substantially affect relative risk estimation in EMR-based drug safety studies, since missing data are not often completely at random. Little improvement was seen in these data in terms of power with the inclusion of longitudinal MI compared with cross-sectional MI. The strategy for handling missing data in drug safety studies can have a large impact on both risk estimates and precision.

Comparative anti-fracture effectiveness of different oral anti-osteoporosis therapies based on "real-world" data: a meta-analysis of propensity-matched cohort findings from the UK Clinical Practice Research Database and the Catalan SIDIAP Database.

PURPOSE: This paper aims to compare the clinical effectiveness of oral anti-osteoporosis drugs based on the observed risk of fracture while on treatment in primary care actual practice. MATERIALS AND METHODS: We investigated two primary care records databases covering UK National Health Service (Clinical Practice Research Datalink, CPRD) and Catalan healthcare (Information System for Research in Primary Care, SIDIAP) patients during 1995-2014 and 2006-2014, respectivey. Treatment-naive incident users of anti-osteoporosis drugs were included and followed until treatment cessation, switching, death, transfer out, or study completion. We considered hip fracture while on treatment as main outcome and major osteoporotic fractures (hip, clinical spine, wrist, and proximal humerus) as secondary outcome. Users of alendronate (reference group) were compared to those of (1) OBP, (2) strontium ranelate (SR), and (3) selective estrogen receptor modulators (SERMs), after matching on baseline characteristics using propensity scores. Multiple imputation was used to handle missing data on confounders and competing risk modelling for the calculation of relative risk according to therapy. Country-specific data were analyzed separately and meta-analyzed. RESULTS: A total of 163,950 UK and 145,236 Catalan patients were identified. Hip (sub-hazard ratio [SHR] [95% CI] 1.04 [0.77-1.40]) and major osteoporotic (SHR [95% CI] 1 [0.78-1.27]) fracture risks were similar among OBP compared to alendronate users. Both hip (SHR [95% CI] 1.26 [1.14-1.39]) and major osteoporotic (SHR [95% CI] 1.06 [1.02-1.12]) fracture risk were higher in SR compared to alendronate users. SERM users had a reduced hip (SHR [95% CI] 0.75 [0.60-0.94]) and major osteoporotic (SHR [95% CI] 0.77 [0.72-0.83]) fracture risk compared to alendronate users. CONCLUSION: We found a 26% excess hip fracture risk among SR compared to matched alendronate users, in line with placebo-controlled RCT findings. Conversely, in a lower risk population, SERM users had a 25% reduced hip fracture risk compared to alendronate users. Head-to-head RCTs are needed to confirm these findings.