Variations géographiques de la prévalence et de l’incidence de la sclérodermie systémique

Estimating the prevalence of systemic sclerosis in the Lorraine region, France, by the capture-recapture method

OBJECTIVE

To assess the prevalence of systemic sclerosis (SSc) in the Lorraine region, France.

METHODS

Data from three sources - general practitioners and community and hospital specialists, medical records departments, and regional and national laboratories-and a capture-recapture method with log-linear models were used to estimate SSc prevalence in the region. Double recording was checked, and reported cases were validated after a review of medical records.

RESULTS

We identified 560 records of suspected SSc cases corresponding to 327 unique suspected SSc cases existing on June 30, 2006, in Lorraine. On the basis of the 193 validated cases (22 [11.4%] with diffuse disease, 136 [70.5%] with limited disease, 31 [16.1%] with limited involvement and 4 unknown), the observed overall crude prevalence of SSc was 105.4 cases per million adult inhabitants (95% confidence interval [CI]: 91.0; 121.4). With the capture-recapture method, the estimated number of SSc cases was 233 (95% CI: 217.3; 260.0), so an estimated 40 cases were not identified by the three sources. The estimated overall prevalence was 132.2 cases per million adult inhabitants (95% CI: 115.8; 154.0).

CONCLUSIONS

Our study provides the first estimate of SSc prevalence in the Lorraine region. The capture-recapture method allowed us to estimate an additional 21% of unobserved cases and is a good alternative to the community-based study design for estimating the prevalence of rare diseases.

L'hypertension artérielle pulmonaire associée à la sclérodermie systémique : proposition d'un algorithme échocardiographique de dépistage pour un diagnostic précoce (ItinérAIR–Sclérodermie)

PURPOSE

Pulmonary arterial hypertension (PAH) is a severe complication of scleroderma. Its prevalence varies from 5% to 35% in the literature. A systematic yearly screening is recommended for early detection and management of PAH, but no precise algorithm is yet available.

METHODS

From literature analysis as well as evaluation of medical needs and practices, a multidisciplinary board of experts proposed an algorithm for the screening of PAH in scleroderma.

RESULTS

This algorithm is based on a precise Doppler echocardiography methodology for the purpose of screening scleroderma patients for PAH. Patients are considered as being at high or low risk of PAH depending on the maximal tricuspid regurgitation velocity. High-risk patients undergo right heart catheterization for confirmation of the diagnosis of PAH. A French multicenter transversal observational study ("ItinérAIR Sclérodermie") will be conducted in 21 hospital centers in France and involved 100 investigators organized as multidisciplinary networks.

FUTURE PROSPECTS

Final results will provide confirmation that the screening algorithm is applicable in a real world setting, as well as a better knowledge of the prevalence of PAH in the various sub-groups of scleroderma patients, of the risk profile for PAH and of the value of DLCO as a predictive factor for PAH, and will support elaboration of precise screening guidelines.