Prise en charge et coûts de la bronchopneumopathie chronique obstructive en France en 2011

RésuméIntroductionCette étude vise à estimer une prévalence de la bronchopneumopathie chronique obstructive (BPCO) traitée et les coûts associés par degré de sévérité.MéthodeElle a été conduite sur les données 2011 de l’échantillon généraliste de bénéficiaires (EGB). Cet échantillon représente 1/97e des bénéficiaires des principaux régimes d’assurance maladie obligatoire. Les cas et leur sévérité ont été identifiés à partir d’algorithmes originaux. Les coûts ont été établis dans une perspective collective.RésultatsLe taux de prévalence minimale de la BPCO traitée a été estimé à 3,8 % dans la population âgée de 40ans et plus, et 1,9 % tous âges confondus. La population (58,2 % d’hommes) avait 68,8±12,7ans d’âge moyen. Au total, 6,2 % des patients ont eu des consommations de soins évocatrices d’un stade très sévère, 8,1 %, 13,8 % et 71,9 % d’un stade sévère, modéré ou peu sévère. Sur une année, 28,8 % ont consulté un pneumologue, 5,0 % ont été hospitalisés (≥24h) pour BPCO et 6,7 % sont décédés. En moyenne, les patients ont eu 1,7±1,5 exacerbations/an et seulement 61,4 % ont reçu un traitement médicamenteux spécifique. La consommation annuelle moyenne de soins d’un patient a été estimée à 9382€ dont 5516€ attribuable à la BPCO.ConclusionCette étude utilisant des bases de données médico-administratives confirme l’importance du fardeau épidémiologique et économique de la BPCO en France.SummaryObjectivesTo estimate the prevalence of treated chronic obstructive pulmonary disease (COPD) and its associated costs by stage of severity.MethodsThe study was conducted on the 2011 data of the french general beneficiary sample database (EGB). EGB is a 1/97th sample of the whole population of the beneficiaries of the main compulsory national health insurances. COPD cases and the level of severity of the disease have been identified using new algorithms established from the available parameters in EGB. Costs were estimated using a collective perspective.ResultsThe minimal prevalence of treated COPD was estimated at 3.8% in patients of 40 years and older and 1.9% regardless of the age of individuals. This population was predominantly male (58.2%) with a mean age of 68.8 years (±12.7). A total of 6.2% of patients had a health-care utilization suggestive of a very severe stage of COPD and 8.1%, 13.8% and 71.9% suggestive of severe, moderate and mild stages respectively. Over one year, 28.8% of patients visited a specialist respiratory physician, 5.0% were hospitalized (≥24h) for COPD and 6.7% died. Patients experienced an average of 1.7 (±1.5) exacerbations per year and only 61.4% received specific pharmacological treatment for COPD during the year. The average yearly health-care cost of a patient with COPD was estimated at €9382, with €5342 directly related to COPD.ConclusionThis study based on medico-administrative databases confirms the high epidemiological and economic burden of COPD in France

Estimating spring terminus submarine melt rates at a greenlandic tidewater glacier using satellite imagery

Oceanic forcing of the Greenland Ice Sheet is believed to promote widespread thinning at tidewater glaciers, with submarine melting proposed as a potential trigger of increased glacier calving, retreat, and subsequent acceleration. The precise mechanism(s) driving glacier instability, however, remain poorly understood, and while increasing evidence points to the importance of submarine melting, estimates of melt rates are uncertain. Here we estimate submarine melt rate by examining freeboard changes in the seasonal ice tongue of Kangiata Nunaata Sermia (KNS) at the head of Kangersuneq Fjord (KF), southwest Greenland. We calculate melt rates for March and May 2013 by differencing along-fjord surface elevation, derived from high-resolution TanDEM-X digital elevation models (DEMs), in combination with ice velocities derived from offset tracking applied to TerraSAR-X imagery. Estimated steady state melt rates reach up to 1.4 ± 0.5m d-1 near the glacier grounding line, with mean values of up to 0.8 ± 0.3 and 0.7 ± 0.3m d-1 for the eastern and western parts of the ice tongue, respectively. Melt rates decrease with distance from the ice front and vary across the fjord. This methodology reveals spatio-temporal variations in submarine melt rates (SMRs) at tidewater glaciers which develop floating termini, and can be used to improve our understanding of ice-ocean interactions and submarine melting in glacial fjords.Publisher PDFPeer reviewe

Reversed Surface-Mass-Balance Gradients on Himalayan Debris-Covered Glaciers Inferred from Remote Sensing

Meltwater from the glaciers in High Mountain Asia plays a critical role in water availability and food security in central and southern Asia. However, observations of glacier ablation and accumulation rates are limited in spatial and temporal scale due to the challenges that are associated with fieldwork at the remote, high-altitude settings of these glaciers. Here, using a remote-sensing-based mass-continuity approach, we compute regional-scale surface mass balance of glaciers in five key regions across High Mountain Asia. After accounting for the role of ice flow, we find distinctively different altitudinal surface-mass-balance gradients between heavily debris-covered and relatively debris-free areas. In the region surrounding Mount Everest, where debris coverage is the most extensive, our results show a reversed mean surface-mass-balance gradient of −0.21 ± 0.18 m w.e. a−1 (100 m)−1 on the low-elevation portions of glaciers, switching to a positive mean gradient of 1.21 ± 0.41 m w.e. a−1 (100 m)−1 above an average elevation of 5520 ± 50 m. Meanwhile, in West Nepal, where the debris coverage is minimal, we find a continuously positive mean gradient of 1.18 ± 0.40 m w.e. a−1 (100 m)−1. Equilibrium line altitude estimates, which are derived from our surface-mass-balance gradients, display a strong regional gradient, increasing from northwest (4490 ± 140 m) to southeast (5690 ± 130 m). Overall, our findings emphasise the importance of separating signals of surface mass balance and ice dynamics, in order to constrain better their contribution towards the ice thinning that is being observed across High Mountain Asia

Assimilation of satellite-derived melt extent increases melt simulated by MAR over the Amundsen sector (West Antarctica)

Surface melt over the Antarctic ice shelves is one of the largest uncertainties related to sea level rise over the 21st century. However, current climate models still struggle to accurately represent it, limiting our comprehension of processes driving melt spatial and temporal variability and its consequences on the stability of the Antarctic ice sheet. Recent advances in Earth monitoring thanks to satellites have enabled new estimations of Antarctic melt extent. They can detect if and where melt occurs, while the amount of meltwater produced can only be deduced from model simulations. In order to combine advantages of both tools, we present new melt estimates based on a regional climate model assimilating the satellite-derived melt extent. This improves the comparison between model and satellite estimates paving the way for a re-estimation of the amount of melt produced each year on the surface of the entire Antarctic ice sheet.La fonte de surface sur les plateformes de glace en Antarctique est l'une des plus grandes incertitudes liées à l'augmentation du niveau de la mer pendant le 21e siècle. Cependant, les modèles climatiques actuels peinent encore à la représenter avec précision, ce qui limite la compréhension des processus expliquant sa variabilité spatiale et temporelle et ses conséquences sur la stabilité de l’inlandsis de l’Antarctique. Les progrès récents de surveillance de la Terre grâce aux satellites ont permis de créer de nouvelles estimations de l'étendue de la fonte en Antarctique. Ceux-ci peuvent détecter si et où la fonte se produit, tandis que la quantité d'eau de fonte produite ne peut par contre être déduite que de simulations climatiques. Afin de combiner les avantages des deux outils, nous présentons de nouvelles estimations de la fonte basées sur un modèle climatique régional assimilant l'étendue de la fonte dérivée des satellites. Cela améliore la comparaison entre les estimations du modèle et du satellite, ouvrant ainsi la voie à une ré-estimation de la quantité de fonte produite chaque année à la surface de l'ensemble de l'inlandsis de l’Antarctique

Evolution of supraglacial lakes on the Larsen B ice shelf in the decades before it collapsed

The Larsen B ice shelf collapsed in 2002 losing an area twice the size of Greater London to the sea (3,000 km 2), in an event associated with widespread supraglacial lake drainage. Here we use optical and radar satellite imagery to investigate the evolution of the ice shelf's lakes in the decades preceding collapse. We find (1) that lakes spread southward in the preceding decades at a rate commensurate with meltwater saturation of the shelf surface; (2) no trend in lake size, suggesting an active supraglacial drainage network which evacuated excess water off the shelf; and (3) lakes mostly refreeze in winter but the few lakes that do drain are associated with ice breakup 2–4 years later. Given the relative scale of lake drainage and shelf breakup, however, it is not clear from our data whether lake drainage is more likely a cause, or an effect, of ice shelf collapse