title: Severity of illness index for surgical departments in a Cuban hospital: a revalidation study.
abstract: In the context of the evaluation of hospital services, the incorporation of severity indices allows an essential control variable for performance comparisons in time and space through risk adjustment. The severity index for surgical services was developed in 1999 and validated as a general index for surgical services. Sixteen years later the hospital context is different in many ways and a revalidation was considered necessary to guarantee its current usefulness.
  
  
  
  To evaluate the validity and reliability of the surgical services severity index to warrant its reasonable use under current conditions.
  
  
  
  A descriptive study was carried out in the General Surgery service of the "Hermanos Ameijeiras" Clinical Surgical Hospital of Havana, Cuba during the second half of 2010. We reviewed the medical records of 511 patients discharged from this service. Items were the same as the original index as were their weighted values. Conceptual or construct validity, criterion validity and inter-rater reliability as well as internal consistency of the proposed index were evaluated.
  
  
  
  Construct validity was expressed as a significant association between the value of the severity index for surgical services and discharge status. A significant association was also found, although weak, with length of hospital stay. Criterion validity was demonstrated through the correlations between the severity index for surgical services and other similar indices. Regarding criterion validity, the Horn index showed a correlation of 0.722 (95% CI: 0.677-0.761) with our index. With the POSSUM score, correlation was 0.454 (95% CI: 0.388-0.514) with mortality risk and 0.539 (95% CI: 0.462-0.607) with morbidity risk. Internal consistency yielded a standardized Cronbach's alpha of 0.8; inter-rater reliability resulted in a reliability coefficient of 0.98 for the quantitative index and a weighted global Kappa coefficient of 0.87 for the ordinal surgical index of severity for surgical services (IGQ).
  
  
  
  The validity and reliability of the proposed index was satisfactory in all aspects evaluated. The surgical services severity index may be used in the original context and is easily adaptable to other contexts as well.
authors.affiliation: Departamento de Admisión, Archivo y Estadística, Centro de Investigaciones Médico Quirúrgico (CIMEQ), La Habana, Cuba. Address: Calle San Lázaro 701, Centro Habana, La Habana, Cuba. Email: amadimb@gmail.com.
authors.forename: Amadys
authors.initials: A
authors.lastname: Armas-Bencomo
authors.affiliation: Departamento de Investigaciones y Proyectos, Hospital Hermanos Ameijeiras, La Habana, Cuba.
authors.forename: Teddy Osmin
authors.initials: TO
authors.lastname: Tamargo-Barbeito
authors.affiliation: Servicio de Cirugía General, Hospital Hermanos Ameijeiras, La Habana, Cuba.
authors.forename: Edelberto
authors.initials: E
authors.lastname: Fuentes-Valdés
authors.affiliation: Departamento de Investigaciones y Proyectos, Hospital Hermanos Ameijeiras, La Habana, Cuba.
authors.forename: Rosa Eugenia
authors.initials: RE
authors.lastname: Jiménez-Paneque
mesh_terms: D003462:Cuba; D006801:Humans; D007902:Length of Stay; D015588:Observer Variation; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013503:Surgery Department, Hospital; D013514:Surgical Procedures, Operative
keywords:  reliability;  risk adjustment;  validity; severity of illness index