Montse Ferrer

El Cuestionario de Salud SF-36 español: una década de experiencia y nuevos desarrollos

Objetivo: El Cuestionario SF-36 es uno de los instrumentos de Calidad de Vida Relacionada con la Salud (CVRS) mas utilizados y evaluados. Tras una decada de uso este articulo revisa criticamente el contenido, propiedades metricas y nuevos desarrollos de la version espanola. Metodos: Revision de los articulos indizados en Medline (PubMed) y en las bases de datos IBECS e IME que han utilizado la version espanola del cuestionario. Se seleccionaron los articulos con informacion sobre modelo de medida, fiabilidad, validez y sensibilidad al cambio del instrumento. Resultados: Se encontraron 79 articulos, 17 de los cuales describian caracteristicas metricas del cuestionario. En el 96% las escalas superaron el estandar propuesto de fiabilidad (α de Cronbach) de 0,7. Las estimaciones agrupadas obtenidas por metaanalisis fueron superiores a 0,7 en todos los casos. El SF-36 mostro buena discriminacion entre grupos de gravedad, correlacion moderada con indicadores clinicos y alta con otros instrumentos de CVRS. El SF-36 predijo mortalidad y detecto mejoria tras la angioplastia coronaria, la cirugia de hipertrofia prostatica benigna o la ventilacion domiciliaria no invasiva. Los nuevos desarrollos descritos (puntuaciones basadas en normas, la version 2, el SF-12 y el SF-8) mejoraron sus propiedades metricas y su interpretacion. Conclusiones: El SF-36, conjuntamente con las nuevas versiones desarrolladas, es un instrumento muy adecuado para su uso en investigacion y en la practica clinica.

Validation of the "World Health Organization Disability Assessment Schedule, WHODAS-2" in patients with chronic diseases

BackgroundThe WHODAS-2 is a disability assessment instrument based on the conceptual framework of the International Classification of Functioning, Disability, and Health (ICF). It provides a global measure of disability and 7 domain-specific scores. The aim of this study was to assess WHODAS-2 conceptual model and metric properties in a set of chronic and prevalent clinical conditions accounting for a wide scope of disability in Europe.Methods1,119 patients with one of 13 chronic conditions were recruited in 7 European centres. Participants were clinically evaluated and administered the WHODAS-2 and the SF-36 at baseline, 6 weeks and 3 months of follow-up. The latent structure was explored and confirmed by factor analysis (FA). Reliability was assessed in terms of internal consistency (Cronbachs alpha) and reproducibility (intra-class correlation coefficients, ICC). Construct validity was evaluated by correlating the WHODAS-2 and SF-36 domains, and comparing known groups based on the clinical-severity and work status. Effect size (ES) coefficient was used to assess responsiveness. To assess reproducibility and responsiveness, subsamples of stable (at 6 weeks) and improved (after 3 moths) patients were defined, respectively, according to changes in their clinical-severity.ResultsThe satisfactory FA goodness of fit indexes confirmed a second order factor structure with 7 dimensions, and a global score for the WHODAS-2. Cronbachs alpha ranged from 0.77 (self care) to 0.98 (life activities: work or school), and the ICC was lower, but achieved the recommended standard of 0.7 for four domains. Correlations between global WHODAS-2 score and the different domains of the SF-36 ranged from -0.29 to -0.65. Most of the WHODAS-2 scores showed statistically significant differences among clinical-severity groups for all pathologies, and between working patients and those not working due to ill health (p < 0.001). Among the subsample of patients who had improved, responsiveness coefficients were small to moderate (ES = 0.3-0.7), but higher than those of the SF-36.ConclusionsThe latent structure originally designed by WHODAS-2 developers has been confirmed for the first time, and it has shown good metric properties in clinic and rehabilitation samples. Therefore, considerable support is provided to the WHODAS-2 utilization as an international instrument to measure disability based on the ICF model.

Off-line signature verification based on grey level information using texture features

A method for conducting off-line handwritten signature verification is described. It works at the global image level and measures the grey level variations in the image using statistical texture features. The co-occurrence matrix and local binary pattern are analysed and used as features. This method begins with a proposed background removal. A histogram is also processed to reduce the influence of different writing ink pens used by signers. Genuine samples and random forgeries have been used to train an SVM model and random and skilled forgeries have been used for testing it. Results are reasonable according to the state-of-the-art and approaches that use the same two databases: MCYT-75 and GPDS-100 Corpuses. The combination of the proposed features and those proposed by other authors, based on geometric information, also promises improvements in performance.

Disease-specific health-related quality of life questionnaires for heart failure: a systematic review with meta-analyses.

BackgroundHeart failure (HF) is an increasingly common condition affecting patients’ health-related quality of life (HRQL). However, there is little literature comparing HF-specific instruments. Our aim was to evaluate and compare data on the conceptual model and metric properties (reliability, validity and responsiveness) of HF-specific HRQL instruments, by performing a systematic review with meta-analyses.Methods and resultsOf 2,541 articles initially identified, 421 were full-text reviewed. Ninety-four reported data on five questionnaires: Minnesota Living with Heart Failure Questionnaire (MLHFQ), Chronic Heart Failure Questionnaire (CHFQ), Quality of Life Questionnaire for Severe Heart Failure (QLQ-SHF), Kansas City Cardiomyopathy Questionnaire (KCCQ) and Left Ventricular Dysfunction (LVD-36) questionnaire. Metric properties (reliability, validity and responsiveness) were summarised using meta-analysis for pools above five estimates. Cronbach’s alpha coefficients were generally high (0.83–0.95) for overall scores and scales measuring physical health. Associations with four validity criteria (New York Heart Association [NYHA] class, six-minute walk test [6MWT] and short form-36 [SF-36] ‘Physical’ and ‘Social Functioning’) were moderate to strong (0.41–0.84), except for those between two CHFQ domains (fatigue and dyspnoea) and the NYHA (0.19 and 0.22). Pooled estimates of change from eight meta-analyses showed the MLHFQ to be highly responsive, with changes in overall score ranging from −9.6 (95% confidence interval [CI]: −4.1; −15.2) for placebo to −17.7 (95% CI: −15.3; −20.2) for pacing devices. The CHFQ and KCCQ also showed good sensitivity to change.ConclusionsMost of the questionnaires studied met minimum psychometric criteria, though current evidence would primarily support the use of the MLHFQ, followed by the KCCQ and CHFQ.

The Spanish version of the Short Form 36 Health Survey: a decade of experience and new developments

OBJECTIVE The Short Form-36 Health Survey (SF-36) is one of the most widely used and evaluated generic health-related quality of life (HRQL) questionnaires. After almost a decade of use in Spain, the present article critically reviews the content and metric properties of the Spanish version, as well as its new developments. METHODS A review of indexed articles that used the Spanish version of the SF-36 was performed in Medline (PubMed), the Spanish bibliographic databases IBECS and IME. Articles that provided information on the measurement model, reliability, validity, and responsiveness to change of the instrument were selected. RESULTS Seventy-nine articles were found, of which 17 evaluated the metric characteristics of the questionnaire. The reliability of the SF-36 scales was higher than the suggested standard (Cronbachs alpha) of 0.7 in 96% of the evaluations. Grouped evaluations obtained by meta-analysis were higher than 0.7 in all cases. The SF-36 showed good discrimination among severity groups, moderate correlations with clinical indicators, and high correlations with other HRQL instruments. Moreover, questionnaire scores predicted mortality and were able to detect improvement due to therapeutic interventions such as coronary angioplasty, benign prostatic hyperplasia surgery, and non-invasive positive pressure home ventilation. The new developments (norm-based scoring, version 2, the SF-12 and SF-8) improved both the metric properties and interpretation of the questionnaire. CONCLUSIONS The Spanish version of the SF-36 and its recently developed versions is a suitable instrument for use in medical research, as well as in clinical practice.

Development of EMPRO: a tool for the standardized assessment of patient-reported outcome measures.

OBJECTIVE This study was aimed to develop a tool for the standardized assessment of patient-reported outcomes (PROs) to assist the choice of instruments. METHODS An expert panel adapted the eight attributes proposed by the Medical Outcomes Trust as evaluation review criteria, created items to evaluate them, and included a response scale for each item. A pilot test was designed to test the new tools feasibility and to obtain preliminary information concerning its psychometric properties. The Spanish versions of five measures were selected for assessment: the SF-36 Health Survey, the Nottingham Health Profile, the COOP-WONCA charts, the EuroQol-5D, and the Quality of Life Questionnaire EORTC-QLQ-C30. We assessed the new tools reliability (Cronbachs alpha and intraclass correlation coefficient [ICC]) and construct validity. RESULTS The new EMPRO (Evaluating the Measurement of Patient-Reported Outcomes) tool has 39 items covering eight key attributes: conceptual and measurement model, reliability, validity, responsiveness, interpretability, burden, alternative modes of administration, and cross-cultural and linguistic adaptations. Internal consistency was high (alpha = 0.95) as was interrater concordance (ICC: 0.87-0.94). Positive associations consistent with a priori hypotheses were observed between EMPRO attribute scores and the number of articles identified for the measures, the years elapsed since the publication of the first article, and the number of citations. CONCLUSION A new tool for the standardized assessment of PRO measures is available. It has shown good preliminary reliability and validity and should be a useful aid to investigators who need to choose between alternative measures. Further assessment of the tool is necessary.

Are results of the SF-36 health survey and the nottingham health profile similar?: A comparison in COPD patients

A number of questionnaires have been used to assess the health-related quality of life of patients with chronic obstructive pulmonary disease (COPD). The study compares the performance of the SF-36 and the Nottingham Health Profile (NHP) in a sample of 321 male patients with COPD. Score distributions, reliability estimates, and several item scaling tests, including Rasch analysis were compared. Finally, we assessed the relative ability of the two instruments considered in discriminating different levels of disease severity by comparing: (a) their correlations with dyspnea and %FEV1; the receiver operating characteristic (ROC) curves; and the F-statistics. The SF-36 scores were less skewed and more homogeneously distributed than NHP scores. Item scaling tests and reliability estimates showed a better performance of SF-36 items and scales. Nevertheless, results of Rasch analysis evidenced that both instruments have very similar scaling characteristics. Validity results did not show a consistent pattern of superiority for either of the instruments. For the physical domain, correlations of NHP and SF-36 scores with %FEV1 and dyspnea were very similar and substantial (tau > or = 0.30). F-statistics showed that SF-36 physical scale was more precise (86%) than the NHP counterpart in discriminating among levels of dyspnea and %FEV1 impairment. Nevertheless, the ROC curve and its associated area under the curve did not show a significant difference (p > 0.10). Overall results suggest that both instruments are similar in discriminating among different levels of respiratory impairment.

Prevalence of Low Back Pain and Its Effect on Health-Related Quality of Life in Adolescents

OBJECTIVES To assess the prevalence of low back pain (LBP) in adolescents and the clinical features of LBP in 2 European countries and to evaluate the effect of LBP on health-related quality of life (HRQOL) using standardized validated generic and disease-specific instruments. DESIGN Cross-sectional study. SETTING Secondary schools of Barcelona, Spain, and Fribourg, Switzerland. PARTICIPANTS Representative sample of adolescents from the 2 cities. Intervention Selected adolescents completed a questionnaire including a generic HRQOL (KIDSCREEN-52) and 2 LBP-specific instruments. MAIN OUTCOME MEASURES Results of KIDSCREEN-52, the Roland-Morris Disability Questionnaire, and the Hanover Functional Ability Questionnaire. RESULTS A total of 1470 adolescents (52.6% male) with a mean (SD) age of 15.05 (1.17) years completed the questionnaires (response rate, 85.1%). Low back pain was reported by 587 adolescents (39.8%): isolated LBP in 250 (42.6%), LBP plus other pain in 271(46.2%), LBP plus whole-body pain in 50 (8.5%, and unclassifiable LBP in 16 (2.7%). Five hundred adolescents (34.7%) reported no pain, and 369 (25.6%) reported other pain without LBP. In those with isolated LBP, the percentage of adolescent boys was higher (54.6%; P < .001) and the LBP was mildest. In those with LBP plus whole-body pain, the percentage of adolescent girls was higher (62%; P < .001) and LBP was most severe. All KIDSCREEN scores in the group with LBP plus whole-body pain were significantly lower than in the other groups (effect size, 0.52-1.24). No differences were found between the groups who reported isolated pain, no pain, or other pain with no LBP. On the LBP-specific instruments, adolescents who reported LBP plus other pain had significantly poorer scores (P < .001) compared with those with isolated LBP but better scores (P < .001) than those with LBP plus whole-body pain. CONCLUSIONS Low back pain in adolescents is a prevalent symptom with overall low associated disability and little effect on health-related quality of life. A subset of adolescents in whom LBP is associated with whole-body pain report significant impairment and deserve more attention.

Off-line Handwritten Signature GPDS-960 Corpus

The current need for large databases to evaluate automatic biometric recognition systems has motivated the developing of the GPDS-960 corpus, an off-line handwritten signature database which contains 24 genuine signatures and 30 forgeries of 960 individuals. This paper describes the GPDS signature corpus, gives details about the acquisition protocols and presents preliminary verification results obtained using the GPDS data.

Instrumentos de medida de calidad de vida relacionada con la salud y de otros resultados percibidos por los pacientes

En los ultimos anos se ha consolidado la investigacion en resultados percibidos por los pacientes en general, y de calidad de vida relacionada con la salud en particular, con el desarrollo de un numero elevado de instrumentos de medida. Siguiendo las recomendaciones del comite cientifico del Medical Outcomes Trust, el listado de comprobacion ePRO propone una evaluacion modular de estos instrumentos basada en 8 atributos basicos: el modelo conceptual y de medida, la fiabilidad, la validez, la sensibilidad al cambio, la interpretabilidad de las puntuaciones, la carga de administracion para el entrevistador y el entrevistado, los formatos alternativos al estandar y el proceso de adaptacion transcultural. Para cada atributo se lista un numero variable de criterios que se deberia considerar en su desarrollo. Es de esperar que la adopcion de guias comunes facilite el desarrollo de mejores instrumentos de medida de resultados percibidos por los pacientes.