title: Cross-cultural adaptation, reliability and validity of the Spanish version of the Quality of Life in Adult Cancer Survivors (QLACS) questionnaire: application in a sample of short-term survivors.
abstract: BACKGROUND
  The aim of this study was to validate the Quality of Life in Adult Cancer Survivors (QLACS) in short-term Spanish cancer survivor's patients.
  
  
  METHODS
  Patients with breast, colorectal or prostate cancer that had finished their initial cancer treatment 3 years before the beginning of this study completed QLACS, WHOQOL, Short Form-36, Hospital Anxiety and Depression Scale, EORTC-QLQ-BR23 and EQ-5D. Cultural adaptation was made based on established guidelines. Reliability was evaluated using internal consistency and test-retest. Convergent validity was studied by mean of Pearson's correlation coefficient. Structural validity was determined by a second-order confirmatory factor analysis (CFA) and Rasch analysis was used to assess the unidimensionality of the Generic and Cancer-specific scales.
  
  
  RESULTS
  Cronbach's alpha were above 0.7 in all domains and summary scales. Test-retest coefficients were 0.88 for Generic and 0.82 for Cancer-specific summary scales. QLACS generic summary scale was correlated with other generic criterion measures, SF-36 MCS (r = - 0.74) and EQ-VAS (r = - 0.63). QLACS cancer-specific scale had lower values with the same constructs. CFA provided satisfactory fit indices in all cases. The RMSEA value was 0.061 and CFI and TLI values were 0.929 and 0.925, respectively. All factor loadings were higher than 0.40 and statistically significant (P < 0.001). Generic summary scale had eight misfitting items. In the remaining 20 items, the unidimensionality was supported. Cancer Specific summary scale showed four misfitting items, the remaining showed unidimensionality.
  
  
  CONCLUSIONS
  The findings support the validity and reliability of QLACS questionnaire to be used in short-term cancer survivors.
authors.affiliation: Unidad de Investigación, Hospital Universitario Basurto, Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Avenida Montevideo, 18, 48013, Bilbao, Bizkaia, Spain. antonio.escobarmartinez@osakidetza.eus.
authors.forename: Antonio
authors.initials: A
authors.lastname: Escobar
authors.affiliation: Servicio de Evaluación y Planificación. Dirección del Servicio Canario de la Salud. Fundación Canaria de Investigación Sanitaria (FUNCANIS), Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Camino Candelaria, 44. C.S. San Isidro-El Chorrillo, 38109, El Rosario, Tenerife, Spain. mar.trujillomartin@sescs.es.
authors.forename: Maria del Mar
authors.initials: Mdel M
authors.lastname: Trujillo-Martín
authors.affiliation: Área de Oncología, Hospital Costa del Sol, Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Autovía A-7, Km 187, 29603, Marbella, Málaga, Spain. rueda.dominguez@gmail.com.
authors.forename: Antonio
authors.initials: A
authors.lastname: Rueda
authors.affiliation: Servicio de Oncología Médica, Hospital Costa del Sol, Autovía A-7, Km 187, 29603, Marbella, Málaga, Spain. eliperu@gmail.com.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Pérez-Ruiz
authors.affiliation: Division of Public Health Sciences, Department of Social Sciences and Health Policy, Medical Center Boulevard Wake Forest School of Medicine, Winston-Salem, NC, 27157-1063, USA. navis@wakehealth.edu.
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Avis
authors.affiliation: Unidad de Investigación, Hospital Universitario Basurto, Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Avenida Montevideo, 18, 48013, Bilbao, Bizkaia, Spain. amaia.bilbaogonzalez@osakidetza.eus.
authors.forename: Amaia
authors.initials: A
authors.lastname: Bilbao
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000523:psychology*; D015179:Colorectal Neoplasms / Q000523:psychology*; D003431:Cross-Cultural Comparison; D005163:Factor Analysis, Statistical; D005260:Female; D006630:Hispanic or Latino / Q000523:psychology* / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000523:psychology*; D011594:Psychometrics / Q000295:instrumentation*; D011788:Quality of Life; D015203:Reproducibility of Results; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D017741:Survivors / Q000523:psychology* / Q000706:statistics & numerical data