Observation- and Model-Based Estimates of Particulate Dry Nitrogen Deposition to the Oceans

© Author(s) 2017. This is an Open Access article distributed under the Creative Commons Attribution License CC BY 3.0 ( https://creativecommons.org/licenses/by/3.0/ ). Published by Copernicus Publications on behalf of the European Geosciences Union.Anthropogenic nitrogen (N) emissions to the atmosphere have increased significantly the deposition of nitrate (NO3−) and ammonium (NH4+) to the surface waters of the open ocean, with potential impacts on marine productivity and the global carbon cycle. Global-scale understanding of the impacts of N deposition to the oceans is reliant on our ability to produce and validate models of nitrogen emission, atmospheric chemistry, transport and deposition. In this work,  ∼  2900 observations of aerosol NO3− and NH4+ concentrations, acquired from sampling aboard ships in the period 1995–2012, are used to assess the performance of modelled N concentration and deposition fields over the remote ocean. Three ocean regions (the eastern tropical North Atlantic, the northern Indian Ocean and northwest Pacific) were selected, in which the density and distribution of observational data were considered sufficient to provide effective comparison to model products. All of these study regions are affected by transport and deposition of mineral dust, which alters the deposition of N, due to uptake of nitrogen oxides (NOx) on mineral surfaces. Assessment of the impacts of atmospheric N deposition on the ocean requires atmospheric chemical transport models to report deposition fluxes; however, these fluxes cannot be measured over the ocean. Modelling studies such as the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), which only report deposition flux, are therefore very difficult to validate for dry deposition. Here, the available observational data were averaged over a 5° × 5° grid and compared to ACCMIP dry deposition fluxes (ModDep) of oxidised N (NOy) and reduced N (NHx) and to the following parameters from the Tracer Model 4 of the Environmental Chemical Processes Laboratory (TM4): ModDep for NOy, NHx and particulate NO3− and NH4+, and surface-level particulate NO3− and NH4+ concentrations. As a model ensemble, ACCMIP can be expected to be more robust than TM4, while TM4 gives access to speciated parameters (NO3− and NH4+) that are more relevant to the observed parameters and which are not available in ACCMIP. Dry deposition fluxes (CalDep) were calculated from the observed concentrations using estimates of dry deposition velocities. Model–observation ratios (RA, n), weighted by grid-cell area and number of observations, were used to assess the performance of the models. Comparison in the three study regions suggests that TM4 overestimates NO3− concentrations (RA, n =  1.4–2.9) and underestimates NH4+ concentrations (RA, n =  0.5–0.7), with spatial distributions in the tropical Atlantic and northern Indian Ocean not being reproduced by the model. In the case of NH4+ in the Indian Ocean, this discrepancy was probably due to seasonal biases in the sampling. Similar patterns were observed in the various comparisons of CalDep to ModDep (RA, n =  0.6–2.6 for NO3−, 0.6–3.1 for NH4+). Values of RA, n for NHx CalDep–ModDep comparisons were approximately double the corresponding values for NH4+ CalDep–ModDep comparisons due to the significant fraction of gas-phase NH3 deposition incorporated in the TM4 and ACCMIP NHx model products. All of the comparisons suffered due to the scarcity of observational data and the large uncertainty in dry deposition velocities used to derive deposition fluxes from concentrations. These uncertainties have been a major limitation on estimates of the flux of material to the oceans for several decades. Recommendations are made for improvements in N deposition estimation through changes in observations, modelling and model–observation comparison procedures. Validation of modelled dry deposition requires effective comparisons to observable aerosol-phase species' concentrations, and this cannot be achieved if model products only report dry deposition flux over the ocean.Peer reviewedFinal Published versio

Large-scale, prospective, observational studies in patients with psoriasis and psoriatic arthritis: A systematic and critical review

<p>Abstract</p> <p>Background</p> <p>Observational studies, if conducted appropriately, play an important role in the decision-making process providing invaluable information on effectiveness, patient-reported outcomes and costs in a real-world environment. We conducted a systematic review of large-scale, prospective, cohort studies with the aim of (a) summarising design characteristics, the interventions or aspects of the disease studied and the outcomes measured and (b) investigating methodological quality.</p> <p>Methods</p> <p>We included prospective, cohort studies which included at least 100 adults with psoriasis or psoriatic arthritis. Studies were identified through searches in electronic databases (Pubmed, Medline, Cochrane library, Centre for Reviews and Dissemination). Information on study characteristics were extracted and tabulated and quality assessment, using a checklist of 18 questions, was conducted.</p> <p>Results</p> <p>Thirty five papers covering 16 cohorts met the inclusion criteria. There were ten treatment-related studies, only two of which provided a comparison between treatments, and six non-treatment studies which examined a number of characteristics of the disease including mortality, morbidity, cost of illness and health-related quality of life. All studies included a clinical outcome measure and 11 included patient-reported outcomes, however only two studies reported information on patient utilities and two on costs. The quality of the assessed studies varied widely. Studies did well on a number of quality assessment questions including having clear objectives, documenting selection criteria, providing a representative sample, defining interventions/characteristics under study, defining and using appropriate outcomes, describing results clearly and using appropriate statistical tests. The quality assessment criteria least adhered to involved questions regarding sample size calculations, describing potential selection bias, defining and adjusting for confounders and losses to follow-up, and defining and describing a comparison group.</p> <p>Conclusion</p> <p>The review highlights the need for well designed prospective observational studies on the effectiveness, patient-reported outcomes and economic impact of treatment regimes for patients with psoriasis and psoriatic arthritis in a real-world environment.</p

SAT0638-HPR CHARACTERIZING THE IMPACT OF AXIAL SPONDYLOARTHRITIS ON DAILY LIFE: GENDER AND PATIENT-REPORTED OUTCOMES ASSOCIATED WITH FUNCTIONAL LIMITATION IN CANADA. RESULTS FROM THE IMAS SURVEY

Background: Understanding the most limiting daily activities reported by patients is important for a holistic healthcare approach. Objectives: To evaluate the degree of functional limitation on daily activities and its association with PROs in Canada. Methods: The International Map of Axial Spondyloarthritis (IMAS) is a cross-sectional online survey of non-selected patients with self-reported axSpA conducted in 22 countries and endorsed by the Axial Spondyloarthritis International Federation. IMAS captures the patients’ perspective of the burden of axSpA. The Canadian adaptation included a review of the survey by an advisory board of axSpA patients and a national steering committee composed of the Canadian Spondylitis Association, rheumatologists and axSpA patients. Canadian participants were recruited from 2018 to 2019. Socio-demographics variables, BASDAI and mental health (GHQ-12) data were collected. Degree of functional limitation in 18 daily activities was evaluated using a 3-point Likert scale. Bivariate analysis was performed to assess activities associated with poorer BASDAI and mental health status. Table 1. BASDAI and mental health (GHQ-12)- impact on daily activities (N = 542) BASDAI Mean ± SD GHQ-12 Mean ± SD Low limitation Medium + High Limitation p-value Low limitation Medium + High Limitation p-value Dressing / undressing 5.5 ± 2.0 6.4 ± 4.4 <.001* 4.4 ± 3.8 5.7 ±4.0 .007* Washing / personal grooming 5.6 ±2.0 6.3 ± 2.0 .002* 4.7 ± 4.1 5.6 ± 4.1 .099 Taking a bath / shower 5.6 ±2.0 6.6 ±1.8 <.001* 4.2 ± 4.0 5.9 ± 4.0 .002* Tying shoe laces 5.4 ± 2.0 6.1 ± 2.0 .005* 4.3 ± 3.8 5.2 ± 4.1 .044* Walking / getting around the house 5.5 ± 2.0 6.4 ± 1.9 <.001* 4.2 ± 3.9 5.6 ± 4.1 .005* Stair climbing 5.1 ±1.9 6.3 ±1.8 <.001* 3.4 ± 3.4 5.4 ± 4.0 <.001* Lying down / getting up from bed 5.2 ± 2.0 6.3 ± 1.9 <.001* 3.6 ± 3.6 5.5 ± 4.1 <.001* Going to the toilet 5.4 ± 2.0 6.7 ± 1.9 <.001* 4.3 ± 4.2 5.6 ± 3.9 .024* Shopping 5.6 ± 1.8 6.2 ± 1.9 .003* 4.1 ± 3.7 5.3 ± 4.1 .025* Cooking 5.6 ± 1.9 6.3 ± 1.8 .008* 3.7 ± 3.6 5.8 ±4.2 <.001* Eating 5.9 ± 2.1 6.9 ± 1.9 .024* 5.0 ± 4.4 5.8 ± 3.9 .282 Housework / cleaning 4.9 ± 2.0 6.0 ± 1.8 <.001* 3.7 ± 3.6 4.8 ± 4.0 .021* Walking down the street 5.4 ± 1.9 6.1 ± 2.0 .005* 4.4 ± 3.8 5.1 ± 4.1 .228 Using public transportation 5.6 ± 1.9 6.1 ± 1.9 .180 4.4 ± 4.0 5.3 ± 4.0 .155 Driving 5.5 ± 2.0 6.1 ± 2.1 .021* 4.2 ± 3.9 5.3 ± 4.2 .050 Doing physical exercise 4.7 ± 2.1 5.8 ± 1.9 <.001* 3.4 ± 3.7 4.7 ± 4.0 .002* Engaging in intimate relations 5.2 ± 1.9 6.0 ±1.9 <.001 4.0 ± 3.8 5.1 ± 4.0 .015* Caring for children / grandchildren 5.2 ± 1.9 6.0 ± 2.0 .003 3.7 ± 3.8 5.2 ± 4.1 .005 * p≤.05 Results: 542 axSpA patients participated. Mean age was 44.3±13.9 years and 63% were female. Mean BASDAI was 5.3±2.1, mean GHQ-12 score was 4.0±3.8 and 50% were on biologics. 94% reported ≥1 limitation in daily activities, of which physical exercise (30%), house cleaning (22%), intimacy (21%) and stair climbing (21%) were most commonly severely impacted (high limitation). Women reported significantly higher limitations in house cleaning, stair climbing, driving, moving around the house and caring for young children (p<.05 for all activities vs men). Compared with low limitation, medium–high limitation in most activities was significantly associated with higher disease activity and worsened mental health for the overall population (Table 1). Conclusion: Canadian axSpA patients, particularly women, are limited in daily life activities beyond those captured by other validated scales. Strong association between functional limitation, disease activity and mental health emphasizes the need for holistic evaluation of axSpA patients. Disclosure of Interests: Proton Rahman Grant/research support from: Janssen and Novartis, Consultant of: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, and Pfizer., Speakers bureau: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, Pfizer, Marco Garrido-Cumbrera: None declared, Sherry Rohekar: None declared, Michael Mallinson: None declared, Gerald Major: None declared, Algis Jovaisas: None declared, Nigil Haroon: None declared, Wendy Gerhart: None declared, Artur J. deBrum Fernandes: None declared, Martin Cohen: None declared, Jon Chan: None declared, Patrick Leclerc Employee of: Novartis, Julie Schneiderman Employee of: Novartis, Robert Inman: None declare

SAT0629-HPR FACTORS ASSOCIATED WITH USE OF BIOLOGICAL THERAPIES FOR AXIAL SPONDYLOARTHRITIS IN CANADA. RESULTS FROM THE IMAS SURVEY

Background: Biologics have revolutionized the treatment of axial spondyloarthritis (axSpA). However, there is limited knowledge about factors associated with their use in Canada. Objectives: To evaluate sociodemographic, healthcare and patient-reported outcomes (PROs) associated with the use of biologics in Canadian axSpA patients. Methods: The International Map of Axial Spondyloarthritis (IMAS) is a cross-sectional online survey of non-selected patients with self-reported axSpA, conducted in 21 countries and endorsed by the Axial Spondyloarthritis International Federation (ASIF). IMAS captures the patients’ perspective of the burden of axSpA. The Canadian adaptation included a review of the survey by an advisory board of axSpA patients and a national steering committee composed of the Canadian Spondylitis Association, rheumatologists and patients. Participants were recruited between August 2018 and February 2019. Sociodemographic and healthcare-related variables, as well as PROs (disease activity [BASDAI, 0–10], spinal stiffness [3–12], functional limitation [0–54] and psychological distress [GHQ-12]) were collected. Respondents were divided in 2 groups 1) biologic and 2) NSAIDs or no treatment, based on reported pharmacologic treatments. Statistical analyses were performed to assess associations between variables and biologic use (bivariate) and the relative weight of these associations (multivariate). Results: 542 axSpA patients were recruited. Mean age was 44.3±13.9 years, 63.1% were female, 66.4% married and 81.0% educated to university/college level. 22.8% of patients lived >50 km from their rheumatologist. Mean BASDAI was 5.3±2.1 and mean GHQ-12 score (mental health) was 4.0±3.8. Nearly half (49.6%) were currently on a biologic. Reported incidence of side effects was lower for patients having biologics (42.5%) vs. a NSAIDs (53.7%) as part of their treatment armamentarium. Only 15.7% of patients had discontinued biologic therapy, the main reasons for withdrawal being physician recommendation (50%), side effects (50%) and personal choice (34%). Variables associated with biologic use included: membership of a patient support group (p<0.001), non-manual work (p=0.008), higher income level (p=0.039), having a combination of public and private insurance schemes (p<0.001) and diagnosis by a rheumatologist (p<0.001). Associated PROs were spinal stiffness (p=0.011) and diagnostic delay (p=0.030). In the multivariate analysis, all variables except income and diagnostic delay were associated with biologic use (Table 1). Table 1. Analysis of sociodemographic and clinical variables in relation to pharmacologic treatment Variable Univariate linear regression Multivariate stepwise linear regression B 95% CI B 95% CI Income level 0.001 1.000–1.000 NA NA Employment—manual worker –0.761 0.266–0.822 –0.838 0.228–0.820 Member of a patient support group 0.937 1.797–3.628 1.116 1.754–5.309 Health insurance scheme—combination 0.209 1.162–1.307 0.215 1.132–1.357 Diagnostic delay 0.009 0.993–1.026 NA NA Spinal Stiffness (3–12) 0.099 1.022–1.193 0.220 1.090–1.424 Diagnosed by rheumatologist 0.535 1.412–2.067 0.335 1.041–1.877 B, B coefficient; NA, [not applicable] Conclusion: Canadian axSpA patients with greater social status, disease awareness, and insurance options are more likely to receive biologic therapy. Furthermore, Canadian physicians are more inclined to prescribe biologics to patients with increased spinal stiffness. Disclosure of Interests: Robert Inman: None declared, Marco Garrido-Cumbrera: None declared, Jon Chan: None declared, Martin Cohen: None declared, Artur J. deBrum Fernandes: None declared, Wendy Gerhart: None declared, Nigil Haroon: None declared, Algis Jovaisas: None declared, Gerald Major: None declared, Michael Mallinson: None declared, Sherry Rohekar: None declared, Patrick Leclerc Employee of: Novartis, Julie Schneiderman Employee of: Novartis, Proton Rahman Grant/research support from: Janssen and Novartis, Consultant of: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, and Pfizer., Speakers bureau: Abbott, AbbVie, Amgen, BMS, Celgene, Lilly, Janssen, Novartis, Pfize

Work-Related Issues and Physical and Psychological Burden in Canadian Patients With Axial Spondyloarthritis: Results From the International Map of Axial Spondyloarthritis

Objective. To identify factors associated with work-related issues in Canadian patients with axial spondyloarthritis. Methods. Data from 542 Canadian patients who participated in the International Map of Axial Spondyloarthritis online survey were analyzed. Participants who were employed, unemployed, or on shortterm disability were included in this analysis. Regression analysis was used to study the association between work-related issues, disease activity (Bath Ankylosing Spondylitis Disease Activity Index [BASDAI]), and psychological distress (12-item General Health Questionnaire [GHQ-12]). Results. The mean age of surveyed participants was 44.3 (SD 13.9) years, 81% were university educated, and 52.6% employed. A substantial proportion had high disease activity (BASDAI ≥ 4, 72.1%) and psychological distress (GHQ-12 ≥ 3, 53.1%); 81% had work-related issues. This study analyzed responses from a subset of participants who were either employed, unemployed, or on short-term disability (n = 339). Ninety percent of this subset reported at least 1 work-related issue in the year before questionnaire completion, with the most frequent being absenteeism (49.3%) and missing work for healthcare provider visits (42.5%). Factoring in disability benefits eliminated the association between work-related issues and disease activity for all variables except fatigue (r = 0.217; P = 0.03) and discomfort (r = 0.196; P = 0.047). Difficulty fulfilling working hours (β 2.342, 95% CI 1.413-3.272) and effect on professional advancement (β 1.426, 95% CI 0.355-2.497) were associated with psychological distress. In the presence of disability benefits, only the effect on professional advancement remained (β 2.304, 95% CI 0.082-4.527). Conclusion. Work-related issues are associated with worse patient-reported outcomes, both physical and psychological