Photometric calibration of an in situ broadband optical thickness monitoring of thin films in a large vacuum chamber.

To improve the in situ monitoring of thin films at the Laboratoire des Matériaux Avancés, a broadband optical monitoring of the coated thin films was developed and installed in the biggest ion-beam sputtering machine in the world. Due to the configuration of the coating machine and the chamber strain under vacuum, a standard calibration procedure is impossible and a double-beam optical system is not suitable. A novel theoretical and practical solution to calibrate the measurements was found and is described in this paper.

Volume-outcome relationships in lower extremity arterial bypass surgery.

Objective: We sought to investigate whether a volume-outcome relationship exists for lower extremity arterial bypass (LEAB) surgery.

Methods: All LEAB procedures performed in England between 2002 and 2006 were identified from Hospital Episode Statistics data. A Charlson-type risk profile, including operating hospital annual case volume, was identified per patient.

Epidemiological study of provision of cholecystectomy in England from 2000 to 2009: retrospective analysis of Hospital Episode Statistics.

Background: The aim of this study was to report the trends in provision of cholecystectomy in the National Health System in England over the 9 year period from 2000 to 2009 and to determine the major risk factors associated with subsequent poor outcome.

Methods: The Hospital Episode Statistics database was interrogated to identify all cholecystectomy procedures for biliary stone disease in adult patients (>16 years). Multivariate regression analyses were used to identify independent predictors of in-patient death, 1 year death, conversion to open, major bile duct injury (BDI) requiring operative repair, and length of stay.

Ethnicity coding in a regional cancer registry and in Hospital Episode Statistics.

Background: The collection of ethnicity information as part of cancer datasets is important for planning services and ensuring equal access, and for epidemiological studies. However, ethnicity has generally not been well recorded in cancer registries in the UK. The aim of this study was to determine the completeness of ethnicity coding in the Thames Cancer Registry (TCR) database and within the Hospital Episode Statistics (HES) data as held by the London Health Observatory, and to investigate factors associated with ethnicity being recorded.