Very large fluxes of methane measured above Bolivian seasonal wetlands.

Methane (CH4) mole fractions from the large semiseasonal Llanos de Moxos wetlands (∼70,000 km2) in northern Bolivia were measured by aircraft flights and ground sampling during early March 2019 (late wet season). Daily fluxes of CH4 determined from the measurements using box models and inverse modeling were between 168 (± 50) and 456 (± 145) mg CH4⋅m-2⋅d-1 for the areas overflown, very high compared with those of previous Amazon basin studies. If the seasonality of the CH4 emissions is comparable to other parts of the Amazon Basin, the region could contribute as much as 8% of annual Amazonian CH4 emissions.

Potential impact of European Medicines Agency measures to minimise risk of serious side effects on JAKi prescribing and utilisation in the UK.

OBJECTIVE: Janus kinase inhibitors (JAKi) or targeted synthetic (ts) disease-modifying antirheumatic drugs (DMARDs) effectively treat rheumatoid arthritis (RA). However, due to safety concerns, the European Medicines Agency (EMA) published risk minimisation measures limiting JAKi prescription to certain at-risk patients unless no suitable alternative is available. This analysis included patients who had started their first-ever JAKi before EMA measures were published in a large national cohort study to investigate the potential impact of these measures on JAKi prescribing and utilisation in UK. METHOD: RA patients starting first-ever JAK inhibitor therapy in BSRBR-RA between 13-February-2017 and 31-May-2022 were included. Percentages of patients meeting EMA risk criteria were presented. For at-risk patients, previous number of distinct biological (b) DMARD classes were described. RESULT: A total of 1341 patients were included, and 80% (N = 1075) met ≥1 EMA risk criterion. Of those who met ≥1 risk criterion, 529 patients (49%) had received JAKi as their first or second b/tsDMARD class, whereas 299 (28%) had received ≥3 prior bDMARD classes. CONCLUSION: Four-in-five RA patients commencing JAKi before the EMA advisory were considered 'at-risk' with prescribing only advised if there was no suitable alternative. Almost a third of those patients had already received ≥3 bDMARDs classes, and alternative therapies would be very limited for them; meanwhile, suitable alternatives might have existed for the remaining proportion, especially for those who received JAKi as their first or second b/tsDMARD, and re-evaluation of the suitability of their treatment may be needed.

Trends for opioid prescribing and the impact of the COVID-19 pandemic in patients with rheumatic and musculoskeletal diseases between 2006 and 2021.

OBJECTIVE: To investigate opioid prescribing trends and assess the impact of the COVID-19 pandemic on opioid prescribing in rheumatic and musculoskeletal diseases (RMDs). METHODS: Adult patients with RA, PsA, axial spondyloarthritis (AxSpA), SLE, OA and FM with opioid prescriptions between 1 January 2006 and 31 August 2021 without cancer in UK primary care were included. Age- and gender-standardized yearly rates of new and prevalent opioid users were calculated between 2006 and 2021. For prevalent users, monthly measures of mean morphine milligram equivalents (MME)/day were calculated between 2006 and 2021. To assess the impact of the pandemic, we fitted regression models to the monthly number of prevalent opioid users between January 2015 and August 2021. The time coefficient reflects the trend pre-pandemic and the interaction term coefficient represents the change in the trend during the pandemic. RESULTS: The study included 1 313 519 RMD patients. New opioid users for RA, PsA and FM increased from 2.6, 1.0 and 3.4/10 000 persons in 2006 to 4.5, 1.8 and 8.7, respectively, in 2018 or 2019. This was followed by a fall to 2.4, 1.2 and 5.9, respectively, in 2021. Prevalent opioid users for all RMDs increased from 2006 but plateaued or dropped beyond 2018, with a 4.5-fold increase in FM between 2006 and 2021. In this period, MME/day increased for all RMDs, with the highest for FM (≥35). During COVID-19 lockdowns, RA, PsA and FM showed significant changes in the trend of prevalent opioid users. The trend for FM increased pre-pandemic and started decreasing during the pandemic. CONCLUSION: The plateauing or decreasing trend of opioid users for RMDs after 2018 may reflect the efforts to tackle rising opioid prescribing in the UK. The pandemic led to fewer people on opioids for most RMDs, providing reassurance that there was no sudden increase in opioid prescribing during the pandemic.

A prospective observational cohort study comparing the treatment effectiveness and safety of ciclosporin, dupilumab and methotrexate in adult and paediatric patients with atopic dermatitis: results from the UK-Irish A-STAR register.

BACKGROUND: The main conventional systemic atopic dermatitis (AD) treatments are methotrexate (MTX) and ciclosporin (CyA). Dupilumab was the first novel systemic agent to enter routine clinical practice. There are no head-to-head randomised controlled trials or real-world studies comparing these agents directly. Network meta-analyses provide indirect comparative efficacy and safety data and have shown strong evidence for dupilumab and CyA. OBJECTIVES: The aim of this study was to compare the real-world clinical effectiveness and safety of CyA, dupilumab and MTX in AD. METHODS: We compared the effectiveness and safety of these systemic agents in a prospective observational cohort study of adult and paediatric patients recruited into the UK-Irish Atopic eczema Systemic TherApy Register (A-STAR). Treatment effectiveness measures included Eczema Area and Severity Index (EASI), Patient-Oriented Eczema Measure (POEM), Peak Pruritus Numerical Rating Scale (PP-NRS), Dermatology Life Quality Index (DLQI) and children's DLQI (cDLQI). Minimum duration of treatment was 28 days and follow-up was 12 months. Adjusted Cox-regression was used to compare the hazards of achieving EASI-50, EASI-75 and EASI-90 over time, and linear mixed-effects models were used to estimate changes in efficacy scores. Treatment safety was assessed by examining adverse events (AEs) at follow-up visits. RESULTS: 488 patients (n=311 adults and n=177 children/adolescents) on dupilumab (n=282), methotrexate (n=149), or CyA (n=57) were included. CyA and MTX were primarily used first line, while dupilumab was mainly a second line systemic as per UK National Institute of Clinical and Care Excellence (NICE) recommendations. EASI-50, EASI-75 and EASI-90 were achieved more rapidly in the dupilumab and CyA groups compared to MTX. After adjustment for previous severity, the reduction in EASI, POEM, PP-NRS and DLQI was greater for patients treated with dupilumab compared to MTX. In severe patients the reduction in EASI, POEM, and PP-NRS was even greater with CyA. The incidence of AEs was similar across groups (734, 654 and 594 per 10,000 person-month on CyA, dupilumab and MTX respectively). CONCLUSIONS: This real-world comparison of CyA, dupilumab and MTX in AD suggests that dupilumab is consistently more effective than MTX and that CyA is most effective in very severe disease within one follow-up year.

Evaluation of serious infections, including Mycobacterium tuberculosis, during treatment with biologic disease-modifying antirheumatic drugs: does line of therapy matter?

OBJECTIVES: This study aimed to evaluate if and how the incidence of serious infection (SI) and active tuberculosis (TB) differ among seven biological disease-modifying antirheumatic drugs (bDMARDs) in patients with rheumatoid arthritis (RA) considering the line of therapy. METHODS: Patients with RA from the British Society for Rheumatology Biologics Register-RA cohort who initiated etanercept, certolizumab, infliximab, adalimumab, abatacept, rituximab, or tocilizumab from the first to fifth line of therapy were included. Follow-up extended up to three years. Primary outcome was SI, secondary outcome was TB. Event rates were calculated and compared using Cox proportional-hazards, controlling for confounding with inverse probability of treatment weights. Comparisons were made overall and stratified by line of therapy. Sensitivity analysis restricted to all treatment courses from 2009 (tocilizumab availability) until end of study (2018). RESULTS: Among 33 897 treatment courses (62 513 patient-years) the incidence of SI was 4.4/100 patient-years (95%CI 4.2-4.5). After adjustment, hazards ratios (HR) of SI were slightly higher with adalimumab and infliximab compared with etanercept. However, no clear pattern was observed when stratifying by line of therapy, in terms of incidence rate or hazards ratio. Sensitivity analyses showed similar HR among these treatments. Regarding TB, all 49 cases occurred during the first three lines of treatment and rarely since 2009. CONCLUSION: The risk of serious infections does not appear to be influenced by the line of therapy in patients with RA. However, the risk of tuberculosis seems to be more frequent during the initial lines of treatment or prior to 2009.

Outcomes following switching from etanercept originator to etanercept biosimilar in 1024 RA patients: A matched-analysis of the BSRBR-RA.

OBJECTIVES: Adults with RA are being switched from etanercept originator to biosimilar in non-medical/cost-saving switching. This analysis aims to investigate outcomes in these patients, including (a) drug survival and (b) disease activity at six and 12-month, compared with those who remain on originator. METHODS: Using BSRBR-RA, those who switched directly from etanercept originator to biosimilar were identified and matched to patients receiving originator, based on gender, age, disease duration, originator start year. Drug survival was calculated; Cox-proportional hazard models assessed differences in drug persistence between those who switched versus remaining on originator. Change in DAS28 after six and 12-months was compared between cohorts. Multiple imputation was used. RESULTS: 1024 adults with RA switching from etanercept originator to biosimilar were included, with a matched cohort of patients remaining on originator. Patients who switched onto a biosimilar product were no more likely to discontinue etanercept treatment versus those who remained on originator; hazard ratio 1.06 (95%CI 0.89-1.26), with 65% of patients remaining on treatment at three years. Ninety-five (9%) patients switched back to originator within the first year. After six and 12-months, biosimilar patients were no more likely to have a worsening of DAS28 (>0.6units) compared with those who remained on originator. CONCLUSIONS: This is the largest matched comparative effectiveness analysis showing patients switched from etanercept originator to biosimilar appear to do just as well with regards to disease activity and drug persistence compared with those who remained on originator. These data will be reassuring to clinicians and patients regarding non-medical switching.

Etanercept originator versus etanercept biosimilar for the treatment of rheumatoid arthritis as a first biologic: results from the BSRBR-RA.

OBJECTIVES: Etanercept biosimilars show comparable efficacy to their originators among biologic-naïve patients with RA in randomized controlled trials. Nationwide guidelines have obligated prescribing of etanercept biosimilars from 2016, resulting in significant cost savings. This analysis aimed to compare the effectiveness of etanercept originator vs etanercept biosimilar amongst biologic-naïve RA patients treated in routine clinical practice in the UK. METHODS: Biologic-naïve RA patients starting etanercept in the British Society for Rheumatology Biologics Register in Rhematoid Arthritis (BSRBR-RA) cohort study from 2010 were included. Data collected at start of therapy includes patient demographics and disease activity. Follow-up data includes changes in disease activity and anti-rheumatic therapy. Six- and 12-month primary outcomes include DAS for 28-joints (DAS28) remission, EULAR response and minimal clinically important difference in function. Etanercept drug survival was assessed using Kaplan-Meier and Cox regression, including reasons for treatment withdrawal. Multiple imputation accounted for missing data. Propensity-decile adjustment was used to account for confounding by indication. RESULTS: A total of 1806 biologic-naïve RA patients started etanercept: 1009 originator, 797 biosimilar. At 6 and 12 months, the proportion of patients achieving DAS28 remission and EULAR response were similar between treatments. During follow-up, 19% of originator patients switched onto etanercept biosimilar. Patients were censored at time of switch. Patients on originator were no more likely to stop therapy vs biosimilar; 71% of originator and 76% of biosimilar patients remained on therapy at 1 year. CONCLUSIONS: In one of the largest analyses of patients with RA, biologic-naïve RA patients treated with etanercept originator showed similar outcomes vs biosimilar using real-world data. Drug survival, and disease activity after 6 and 12 months of therapy, was similar between cohorts.

Uptake of tumour necrosis factor-alpha inhibitor biosimilars for psoriasis: a drug utilization study from the British Association of Dermatologists Biologic and Immunomodulators Register (BADBIR).

BACKGROUND: Tumour necrosis factor-alpha inhibitors (TNFi) have revolutionized the treatment of moderate-to-severe psoriasis. Following patent expiry of the originator biologics, TNFi biosimilars became available, presenting the opportunity for significant reductions in drug costs. OBJECTIVES: To describe the uptake of TNFi biosimilars for psoriasis treatment in the UK and Ireland. METHODS: This observational cohort study utilizes data from the British Association of Dermatologists Biologic and Immunomodulators Register (BADBIR), a national pharmacovigilance study register for patients with psoriasis on systemic treatments. We analysed biosimilar uptake trends over time in nine geographical regions of England along with Wales, Scotland, Northern Ireland and the Republic of Ireland. We assessed the incidence of switching to biosimilars in an originator-user cohort (switchers). Patients on originators infliximab, etanercept and adalimumab at the time originator patents expired, entered the cohort on 1 February 2015, August 2015 and October 2018, respectively, and were followed up until 31 October 2021. Trends in biosimilar initiations were assessed in an adalimumab-naïve cohort who started adalimumab between 1 October 2018 and 31 July 2019 (starters). We assessed the associations between patient factors and originator-to-biosimilar switching and biosimilar initiation using a multivariable Cox regression model and a multivariable logistic regression model, respectively. RESULTS: Included in the originator-user cohort were 4202 patients (209 on infliximab, 742 on etanercept and 3251 on adalimumab). For infliximab, etanercept and adalimumab, respectively, the cumulative incidence of originator-to-biosimilar switching increased with time to 14.8%, 23.6% and 66.6% after 3 years. Across geographical regions, 3-year switching rates varied from 0% to 43.7% for infliximab; from 0% to 40.4% for etanercept; and from 12.5% to 84.3% for adalimumab. Out of the 528 patients included in the adalimumab-naïve cohort, 67.8% started on biosimilars. Originator-to-biosimilar switching and biosimilar initiation were more common in men and in patients who had lower Psoriasis Area and Severity Index at cohort entry. CONCLUSIONS: The uptake of biosimilars increased over time and varied considerably across the UK and Ireland; adalimumab had the highest biosimilar uptake rate compared with that of other TNFi drugs.

Effectiveness and survival of methotrexate versus adalimumab in patients with moderate-to-severe psoriasis: a cohort study from the British Association of Dermatologists Biologics and Immunomodulators Register (BADBIR).

BACKGROUND: Most information on the comparative effectiveness and survival of methotrexate (MTX) and adalimumab (ADA) in the treatment of psoriasis is from randomized control trials and may not translate to the everyday clinical setting. OBJECTIVES: To determine the real-world effectiveness and survival of MTX and ADA in patients with moderate-to-severe psoriasis registered in the British Association of Dermatologists Biologics and Immunomodulators Register (BADBIR). METHODS: Eligible patients were registered in BADBIR, ≥ 16 years of age and receiving a first course of MTX or ADA between September 2007 and December 2021, with ≥ 6 months of follow-up. Effectiveness was defined as achieving an absolute Psoriasis Area and Severity Index (PASI) ≤ 2 reported ≥ 13 weeks after the treatment start date until the stop date. The average treatment effect (ATE) was estimated using inverse probability of treatment weighting with propensity score, including baseline covariates. ATE results were presented as risk ratios (RR). A flexible parametric model was used to estimate adjusted standardized average survival, defined as treatment discontinuation associated with ineffectiveness or the occurrence of adverse events (AEs) at 6, 12 and 24 months. Restricted mean survival time (RMST) at 2 years of treatment exposure was calculated. RESULTS: In total, 6575 patients (median age 44 years; 44% female) were analysed; 2659 (40.4%) were prescribed MTX and 3916 (59.5%) ADA. The proportion of patients achieving PASI ≤ 2 was higher in the ADA cohort (77.4%) than in the MTX cohort (37.4%). ADA was more effective than MTX [RR 2.20, 95% confidence interval (CI) 1.98-2.45]. Overall survival associated with ineffectiveness or AEs was lower in the MTX cohort than in the ADA cohort at 6 months [survival estimate 69.7 (95% CI 67.9-71.5) vs. 90.6 (95% CI 89.8-91.4)], 1 year [survival estimate 52.5 (95% CI 50.4-54.8) vs. 80.6 (95% CI 79.5-81.8)] and 2 years [survival estimate 34.8 (95% CI 32.5-37.2) vs. 68.6 (95% CI 67.2-70.0)]. The difference in RMST (years) overall, or when stratified by ineffectiveness and AEs, was 0.53 (95% CI 0.49-0.58), 0.37 (95% CI 0.33-0.42) and 0.29 (95% CI 0.25-0.33), respectively. CONCLUSIONS: Patients on ADA were twice as likely to be clear or nearly clear of psoriasis and were less likely to discontinue their medication than patients on MTX. Findings from this real-world cohort provide important information to aid clinicians managing patients with psoriasis.

Effectiveness and persistence of acitretin, ciclosporin, fumaric acid esters and methotrexate for patients with moderate-to-severe psoriasis: a cohort study from BADBIR.

BACKGROUND: Real-world data evaluating effectiveness and persistence of systemic therapies for patients with psoriasis are limited. Objectives To determine the effectiveness and persistence of acitretin, ciclosporin, fumaric acid esters (FAEs) and methotrexate in patients with moderate-to-severe psoriasis. METHODS: Data from the British Association of Dermatologists Biologics and Immunomodulators Register (BADBIR), a prospective, multicentre pharmacovigilance register of patients with moderate-to-severe psoriasis receiving biologic and/or conventional systemic therapies, were analysed. Eligible patients were ≥ 16 years of age receiving a first course of acitretin, ciclosporin, FAEs or methotrexate between 2007 and 2021 with ≥ 6 months' follow-up. Effectiveness was defined as achieving absolute Psoriasis Area and Severity Index (aPASI) ≤ 2 reported ≥ 4 weeks after treatment start date until date of cessation. To identify baseline clinical variables associated with treatment effectiveness, we used multivariable logistic regression models estimating the adjusted odds ratio (aOR) of achieving aPASI ≤ 2. To describe drug persistence associated with ineffectiveness, occurrence of adverse events or other reasons for discontinuation, survival estimates with 95% confidence intervals (CIs) were obtained using a flexible parametric model. Results were obtained using multiple imputed data. RESULTS: In total, 5430 patients were included in the analysis. Overall, 1023 (19%) patients were receiving acitretin, 1401 (26%) patients were on ciclosporin, 347 (6%) patients were on FAEs, and 2659 (49%) patients were receiving methotrexate at registration. The proportion of patients who achieved aPASI ≤ 2 was lower for those treated with acitretin [n = 118 (21%)] compared with those receiving ciclosporin [n = 233 (34%)], FAEs [n = 43 (29%)] and methotrexate [n = 372 (32%)]. Factors associated with ineffectiveness included prior experience to previous nonbiologic systemic therapies (acitretin) (aOR 0.64, 95% CI 0.42-0.96), male sex (methotrexate) (aOR 0.58, 95% CI 0.46-0.74), comorbidities (aOR 0.70, 95% CI 0.51-0.97) and alcohol consumption (≤ 14 units per week) (ciclosporin) (aOR 0.70, 95% CI 0.50-0.98). Persistence associated with all reasons for discontinuation showed better survival for methotrexate compared with acitretin, ciclosporin and FAEs cohorts at 12 months [survival estimate 46.1 (95% CI 44.0-48.3), 31.9 (95% CI 29.4-34.7), 30.0 (95% CI 27.5-32.4) and 35.0 (95% CI 29.9-40.9), respectively]. CONCLUSIONS: The real-world effectiveness and persistence of acitretin, ciclosporin, FAEs and methotrexate were generally low. Previous nonbiologic systemic therapies, male sex, comorbidities and alcohol consumption were risk factors associated with treatment ineffectiveness.

"Take up to eight tablets per day": Incorporating free-text medication instructions into a transparent and reproducible process for preparing drug exposure data for pharmacoepidemiology.

PURPOSE: Routinely collected prescription data provides drug exposure information for pharmacoepidemiology, informing start/stop dates and dosage. Prescribing information includes structured data and unstructured free-text instructions, which can include inherent variability, such as "one to two tablets up to four times a day". Preparing drug exposure data from raw prescriptions to a research ready dataset is rarely fully reported, yet assumptions have considerable implications for pharmacoepidemiology. This may have bigger consequences for "pro re nata" (PRN) drugs. Our aim was, using a worked example of opioids and fracture risk, to examine the impact of incorporating narrative prescribing instructions and subsequent drug preparation assumptions on adverse event rates. METHODS: R-packages for extracting free-text medication prescription instructions in a structured form (doseminer) and an algorithm for transparently processing drug exposure information (drugprepr) were developed. Clinical Practice Research Datalink GOLD was used to define a cohort of adult new opioid users without prior cancer. A retrospective cohort study was performed using data between January 1, 2017 and July 31, 2018. We tested the impact of varying drug preparation assumptions by estimating the risk of opioids on fracture risk using Cox proportional hazards models. RESULTS: During the study window, 60 394 patients were identified with 190 754 opioid prescriptions. Free-text prescribing instruction variability, where there was flexibility in the number of tablets to be administered, was present in 42% prescriptions. Variations in the decisions made during preparing raw data for analysis led to marked differences impacting the event number (n = 303-415) and person years of drug exposure (5619-9832). The distribution of hazard ratios as a function of the decisions ranged from 2.71 (95% CI: 2.31, 3.18) to 3.24 (2.76, 3.82). CONCLUSIONS: Assumptions made during the drug preparation process, especially for those with variability in prescription instructions, can impact results of subsequent risk estimates. The developed R packages can improve transparency related to drug preparation assumptions, in line with best practice advocated by international pharmacoepidemiology guidelines.

Burden of comorbid conditions in children and young people with juvenile idiopathic arthritis: a collaborative analysis of 3 JIA registries.

OBJECTIVES: Burden of comorbidities are largely unknown in JIA. From 2000, national and international patient registries were established to monitor biologic treatment, disease activity and adverse events in patients with JIA. The aim of this analysis was to investigate in parallel, for the first time, three of the largest JIA registries in Europe/internationally-UK JIA Biologic Registers (BCRD/BSPAR-ETN), German biologic registers (BiKeR/JuMBO), multinational Pharmachild-to quantify the occurrence of selected comorbidities in patients with JIA. METHODS: Information on which data the registers collect were compared. Patient characteristics and levels of comorbidity were presented, focussing on four key conditions: uveitis, MAS, varicella, and history of tuberculosis. Incidence rates of these on MTX/biologic therapy were determined. RESULTS: 8066 patients were registered into the three JIA registers with similar history of the four comorbidities across the studies; however, varicella vaccination coverage was higher in Germany (56%) vs UK/Pharmachild (16%/13%). At final follow-up, prevalence of varicella infection was lower in Germany (15%) vs UK/Pharmachild (37%/50%). Prevalence of TB (0.1-1.8%) and uveitis (15-19%) was similar across all registers. The proportion of systemic-JIA patients who ever had MAS was lower in Germany (6%) vs UK (15%) and Pharmachild (17%). CONCLUSION: This analysis is the first and largest to investigate the occurrence of four important comorbidities in three JIA registries in Europe and the role of anti-rheumatic drugs. Combined, these three registries represent one of the biggest collection of cases of JIA worldwide and offer a unique setting for future JIA outcome studies.

Exploring the disparity between inflammation and disability in the 10-year outcomes of people with rheumatoid arthritis.

OBJECTIVES: To identify groups of people with RA with different disability trajectories over 10 years, despite comparable levels of inflammation. METHODS: Data for this analysis came from three European prospective cohort studies of people with RA [Norfolk Arthritis Register (NOAR), Early RA Network (ERAN), Étude et Suivi des Polyarthrites Indifférenciées Récentes (ESPOIR)]. Participants were assessed regularly over 8 (ERAN) to 10 (NOAR/ESPOIR) years. Inclusion criteria were: recruited after 1 January 2000, <24 months baseline symptom duration, and disability (HAQ) and inflammation [two-component DAS28 (DAS28-2C)] recorded at baseline and at one other follow-up. People in each cohort also completed patient-reported outcome measures at each assessment (pain, fatigue, depressive symptoms). Group-based trajectory models were used to identify distinct groups of people with similar HAQ and DAS28-2C trajectories over follow-up. RESULTS: This analysis included 2500 people with RA (NOAR: 1000, ESPOIR: 766, ERAN: 734). ESPOIR included more women and the participants were younger [mean (standard deviation) age: NOAR: 57.1 (14.6), ESPOIR: 47.6 (12.5), ERAN: 56.8 (13.8); women: NOAR: 63.9%, ESPOIR: 76.9%, ERAN: 69.1%). Within each cohort, two pairs of trajectories following the hypothesized pattern (comparable DAS28-2Cs but different HAQs) were identified. Higher pain, fatigue and depressive symptoms were associated with increased odds of being in the high HAQ trajectories. CONCLUSION: Excess disability is persistent in RA. Controlling inflammation may not be sufficient to alleviate disability in all people with RA, and effective pain, fatigue and mood management may be needed in some groups to improve long-term function.

Isotopic signatures of methane emissions from tropical fires, agriculture and wetlands: the MOYA and ZWAMPS flights.

We report methane isotopologue data from aircraft and ground measurements in Africa and South America. Aircraft campaigns sampled strong methane fluxes over tropical papyrus wetlands in the Nile, Congo and Zambezi basins, herbaceous wetlands in Bolivian southern Amazonia, and over fires in African woodland, cropland and savannah grassland. Measured methane δ13CCH4 isotopic signatures were in the range -55 to -49‰ for emissions from equatorial Nile wetlands and agricultural areas, but widely -60 ± 1‰ from Upper Congo and Zambezi wetlands. Very similar δ13CCH4 signatures were measured over the Amazonian wetlands of NE Bolivia (around -59‰) and the overall δ13CCH4 signature from outer tropical wetlands in the southern Upper Congo and Upper Amazon drainage plotted together was -59 ± 2‰. These results were more negative than expected. For African cattle, δ13CCH4 values were around -60 to -50‰. Isotopic ratios in methane emitted by tropical fires depended on the C3 : C4 ratio of the biomass fuel. In smoke from tropical C3 dry forest fires in Senegal, δ13CCH4 values were around -28‰. By contrast, African C4 tropical grass fire δ13CCH4 values were -16 to -12‰. Methane from urban landfills in Zambia and Zimbabwe, which have frequent waste fires, had δ13CCH4 around -37 to -36‰. These new isotopic values help improve isotopic constraints on global methane budget models because atmospheric δ13CCH4 values predicted by global atmospheric models are highly sensitive to the δ13CCH4 isotopic signatures applied to tropical wetland emissions. Field and aircraft campaigns also observed widespread regional smoke pollution over Africa, in both the wet and dry seasons, and large urban pollution plumes. The work highlights the need to understand tropical greenhouse gas emissions in order to meet the goals of the UNFCCC Paris Agreement, and to help reduce air pollution over wide regions of Africa. This article is part of a discussion meeting issue 'Rising methane: is warming feeding warming? (part 2)'.

The impact of frailty on short-term mortality following primary total hip and knee arthroplasty due to osteoarthritis.

BACKGROUND: We determined the association between frailty and short-term mortality following total hip and knee arthroplasty (THA/TKA) for osteoarthritis and also the impact of THA/TKA on short-term mortality compared with a control population. METHODS: Frailty was assessed using a frailty index (categorised: fit, mild, moderate, severe frailty). The association between frailty and short-term mortality following THA/TKA was assessed using Cox regression. Mortality following THA/TKA was also compared with a control population with osteoarthritis but no previous THA/TKA, matched on year of birth, sex and quintile of index of multiple deprivation. RESULTS: A total of 103,563 cases who had a THA, 125,367 who had a TKA and matched controls contributed. Among those who had surgery, mortality increased with increasing frailty; adjusted hazard ratio (HR) (95% CI) at 30 days in severely frail versus fit: following THA, 2.85 (1.84, 4.39) and following TKA, 2.14 (1.29, 3.53). The predicted probability of 30-day mortality following THA/TKA varied by age, sex and frailty: following THA, from 0.05% among fit women aged 60-64 years to 6.55% among men with severe frailty aged ≥90 years. All-cause 30-day mortality was increased in fit cases following THA and TKA, respectively, versus fit controls (adjusted HR (95% CI), 1.60 (1.15, 2.21) and 2.98 (1.81, 4.89)), though not among cases with mild, moderate or severe frailty versus controls in the same frailty category. CONCLUSION: Short-term mortality increased with increasing frailty following THA/TKA. Comparison of mortality among cases and controls may be affected by a 'healthy surgery' selection effect.

The impact of frailty on patient-reported outcomes following hip and knee arthroplasty.

AIM: to determine the impact of frailty on patient-reported outcomes following hip and knee arthroplasty. METHODS: we used linked primary and secondary care electronic health records. Frailty was assessed using the electronic frailty index (categorised: fit, mild, moderate, severe frailty). We determined the association between frailty category and post-operative Oxford hip/knee score (OHS/OKS) using Tobit regression. We calculated the proportion of patients in each frailty category who achieved the minimally important change (MIC) in OHS (≥8 points) and OKS (≥7 points) and the proportion who reported a successful outcome (hip/knee problems either 'much better' or 'a little better' following surgery). RESULTS: About 42,512 people who had a hip arthroplasty and 49,208 who had a knee arthroplasty contributed data. In a Tobit model adjusted for pre-operative OHS/OKS, age, sex and quintile of index of multiple deprivation, increasing frailty was associated with decreasing post-operative OHS and OKS, respectively, ß-coefficient (95% CI) in severely frail versus fit, -6.97 (-7.44, -6.49) and - 5.88 (-6.28, -5.47). The proportion of people who achieved the MIC in OHS and OKS, respectively, decreased from 92 and 86% among fit individuals to 84 and 78% among those with severe frailty. Patient-reported success following hip and knee arthroplasty, respectively, decreased from 97 and 93% among fit individuals to 90 and 83% among those with severe frailty. CONCLUSION: frailty adversely impacts on patient-reported outcomes following hip and knee arthroplasty. However, even among those with severe frailty, the large majority achieved the MIC in OHS/OKS and reported a successful outcome.

Sleep Disturbance and Quality of Life in Rheumatoid Arthritis: Prospective mHealth Study.

BACKGROUND: Sleep disturbances and poor health-related quality of life (HRQoL) are common in people with rheumatoid arthritis (RA). Sleep disturbances, such as less total sleep time, more waking periods after sleep onset, and higher levels of nonrestorative sleep, may be a driver of HRQoL. However, understanding whether these sleep disturbances reduce HRQoL has, to date, been challenging because of the need to collect complex time-varying data at high resolution. Such data collection is now made possible by the widespread availability and use of mobile health (mHealth) technologies. OBJECTIVE: This mHealth study aimed to test whether sleep disturbance (both absolute values and variability) causes poor HRQoL. METHODS: The quality of life, sleep, and RA study was a prospective mHealth study of adults with RA. Participants completed a baseline questionnaire, wore a triaxial accelerometer for 30 days to objectively assess sleep, and provided daily reports via a smartphone app that assessed sleep (Consensus Sleep Diary), pain, fatigue, mood, and other symptoms. Participants completed the World Health Organization Quality of Life-Brief (WHOQoL-BREF) questionnaire every 10 days. Multilevel modeling tested the relationship between sleep variables and the WHOQoL-BREF domains (physical, psychological, environmental, and social). RESULTS: Of the 268 recruited participants, 254 were included in the analysis. Across all WHOQoL-BREF domains, participants' scores were lower than the population average. Consensus Sleep Diary sleep parameters predicted the WHOQoL-BREF domain scores. For example, for each hour increase in the total time asleep physical domain scores increased by 1.11 points (ß=1.11, 95% CI 0.07-2.15) and social domain scores increased by 1.65 points. These associations were not explained by sociodemographic and lifestyle factors, disease activity, medication use, anxiety levels, sleep quality, or clinical sleep disorders. However, these changes were attenuated and no longer significant when pain, fatigue, and mood were included in the model. Increased variability in total time asleep was associated with poorer physical and psychological domain scores, independent of all covariates. There was no association between actigraphy-measured sleep and WHOQoL-BREF. CONCLUSIONS: Optimizing total sleep time, increasing sleep efficiency, decreasing sleep onset latency, and reducing variability in total sleep time could improve HRQoL in people with RA.

Propensity Score Weighting and Trimming Strategies for Reducing Variance and Bias of Treatment Effect Estimates: A Simulation Study.

To extend previous simulations on the performance of propensity score (PS) weighting and trimming methods to settings without and with unmeasured confounding, Poisson outcomes, and various strengths of treatment prediction (PS c statistic), we simulated studies with a binary intended treatment T as a function of 4 measured covariates. We mimicked treatment withheld and last-resort treatment by adding 2 "unmeasured" dichotomous factors that directed treatment to change for some patients in both tails of the PS distribution. The number of outcomes Y was simulated as a Poisson function of T and confounders. We estimated the PS as a function of measured covariates and trimmed the tails of the PS distribution using 3 strategies ("Crump," "Stürmer," and "Walker"). After trimming and reestimation, we used alternative PS weights to estimate the treatment effect (rate ratio): inverse probability of treatment weighting, standardized mortality ratio (SMR)-treated, SMR-untreated, the average treatment effect in the overlap population (ATO), matching, and entropy. With no unmeasured confounding, the ATO (123%) and "Crump" trimming (112%) improved relative efficiency compared with untrimmed inverse probability of treatment weighting. With unmeasured confounding, untrimmed estimates were biased irrespective of weighting method, and only Stürmer and Walker trimming consistently reduced bias. In settings where unmeasured confounding (e.g., frailty) may lead physicians to withhold treatment, Stürmer and Walker trimming should be considered before primary analysis.

Do people with rheumatoid arthritis maintain their physical activity level at treatment onset over the first year of methotrexate therapy?

OBJECTIVES: To describe how many people with RA reduce their baseline physical activity level over the first year of MTX treatment, and which factors predict this. METHODS: Data came from the Rheumatoid Arthritis Medication Study (RAMS), a prospective cohort of people with early RA starting MTX. Participants reported demographics and completed questionnaires at baseline, and 6 and 12 months, including reporting the number of days per week they performed ≥20 min of physical activity, coded as none, low (1-3 days) or high (4-7 days). The physical activity levels of participants over 12 months are described. Predictors of stopping physical activity were assessed using multivariable logistic regression. RESULTS: In total, 1468 participants were included [median (interquartile range) age 60 (50, 69) years; 957 (65.2%) women]. At baseline, the physical activity levels of the people with RA were: none = 408 (27.8%), low = 518 (35.3%) and high = 542 (36.9%). Eighty percent of participants maintained some physical activity or began physical activity between assessments (baseline to 6 months = 79.3%, 6 months to 12 months = 80.7%). In total, 24.1% of participants reduced physical activity and 11.3% of participants stopped performing physical activity between baseline and 6 months (6 months to 12 months: 22.6% and 10.2%, respectively). Baseline smoking, higher disability and greater socioeconomic deprivation were associated with stopping physical activity. CONCLUSION: Many people with early RA were not performing physical activity when starting MTX, or stopped performing physical activity over the first year of treatment. These people may require interventions to stay active. These interventions need to be mindful of socioeconomic barriers to physical activity participation.

Incidence of Paget's disease of bone in the UK: evidence of a continuing decline.

OBJECTIVES: To characterize the incidence of clinically diagnosed Paget's disease of bone in the UK during 1999-2015 and to determine variations in the incidence of disease by age, sex, geography and level of deprivation. METHODS: Incident cases of Paget's disease occurring between 1999 and 2015 were identified from primary care records. Overall crude incidence and incidence stratified by age and sex was calculated each year from 1999 to 2015. Direct age- and sex-standardized incidence was also calculated. We used Poisson regression to look at variations in incidence by deprivation and UK region. RESULTS: A total of 3592 incident cases of Paget's disease were identified between 1999 and 2015. Incidence increased with age and at all ages was greater in men than women. In women and men, respectively, crude incidence increased from 0.037 and 0.074/10 000 population per year among those 45-49 years of age to 3.7 and 6.3/10 000 population per year among those ≥85 years. The overall standardized incidence decreased from 0.75/10 000 person-years in 1999 to 0.20/10 000 person-years in 2015. After adjustment for age and sex, incidence was >30% higher in the most- compared with least-deprived quintile of deprivation. There was evidence of geographic variation, with the highest incidence in the North West of England, which persisted after adjustment for age, sex and level of deprivation. CONCLUSION: The incidence of clinically diagnosed Paget's disease has continued to decrease since 1999. The reason for the decline in incidence remains unknown, although the rapidity of change points to an alteration in one or more environmental determinants.