Generalization of the kappa coeficient for ordinal categorical data, multiple observers and incomplete designs

This paper presents a generalization of the kappa coefficient for multiple observers and incomplete designs. This generalization involves ordinal categorical data and includes weights which permit pondering the severity of disagreement. A generalization for incomplete designs of the kappa coefficient based on explicit definitions of agreement is also proposed. Both generalizations are illustrated with data from a medical diagnosis pilot study

Physician-Related Variability in the Outcomes of an Invasive Treatment for Neck and Back Pain: A Multi-Level Analysis of Data Gathered in Routine Clinical Practice

[EN] Neuro-reflexotherapy (NRT) is a proven effective, invasive treatment for neck and back pain. To assess physician-related variability in results, data from post-implementation surveillance of 9023 patients treated within the Spanish National Health Service by 12 physicians were analyzed. Separate multi-level logistic regression models were developed for spinal pain (SP), referred pain (RP), and disability. The models included all patient-related variables predicting response to NRT and physician-related variables. The Intraclass Correlation Coefficient (ICC) and the Median Odds Ratio (MOR) were calculated. Adjusted MOR (95% CI) was 1.70 (1.47; 2.09) for SP, 1.60 (1.38; 1.99) for RP, and 1.65 (1.42; 2.03) for disability. Adjusted ICC (95%CI) values were 0.08 (0.05; 0.15) for SP, 0.07 (0.03; 0.14) for RP, and 0.08 (0.04; 0.14) for disability. In the sensitivity analysis, in which the 6920 patients treated during the physicians’ training period were excluded, adjusted MOR was 1.38 (1.17; 1.98) for SP, 1.37 (1.12; 2.31) for RP, and 1.25 (1.09; 1.79) for disability, while ICCs were 0.03 (0.01; 0.14) for SP, 0.03 (0.00; 0.19) for RP, and 0.02 (0.00; 0.10) for disability. In conclusion, the variability in results obtained by different NRT-certified specialists is reasonable. This suggests that current training standards are appropriateS

Nursing workforce characteristics and control of diabetes mellitus in primary care: A multilevel analysis. Spain

Fundamentos: La actividad de enfermería está condicionada por las características de la plantilla. El objetivo fue determinar cómo afectan las características de la plantilla de enfermería de atención primaria (AP) al control de la diabetes mellitus (DM) en personas adultas. Método: Estudio analítico transversal. Instrumentos para la recogida de datos: sistemas de información de AP y cuestionario PES-Nursing Work Index. Participantes: 44.214 pacientes diabéticos en dos zonas de salud de la Comunidad de Madrid: Zona Noroeste (ZNO) con mejor situación socioeconómica y Zona Suroeste (ZSO) con peor situación socioeconómica y los 507 profesionales de enfermería de referencia. Se realizaron análisis multivariantes multinivel de regresión logística. La variable dependiente fue la DM estaba mal controlada (cuando los valores de Hb1Ac eran ≥ a 7%) Resultados: La prevalencia DM mal controlada fue de 40,1% (IC95%:38,2-42,1). Existía un riesgo de un 25% más de peor control si el paciente cambiaba de centro de salud y de un 27% si cambiaba de pareja médico de cabaecera y enfermera. En los modelos de regresión logística multivariante multinivel: para la ZSO a mayor ratio de pacientes mayores de 65 años aumentaba el riesgo de mal control (OR=1,00008 [IC95%:1,00006-1,001]); a mayor proporción de pacientes sin seguimiento por centro de salud peor control (OR=5,1 [IC95%:1,6-15,6]). En los dos modelos por zona de salud, la condición de ser inmigrante económico aumentó el riesgo de mal control, ZSO (OR=1,3 [IC95%:1,03-1,7]); y ZNO (OR=1,29 [IC95%:1,03-1,6]). Conclusiones: Son factores de riesgo de tener mal controlada la diabetes mellitus la mayor proporción de pacientes mayores de 65 años por enfermera, ser inmigrante y la proporción de pacientes sin seguimientoBackground: Nurse activity is determined by the characteristics of nursing staff. The objective was to determine the impact of Primary Health Care (PHC) nursing workforce characteristics on the control of Diabetes Mellitus (DM) in adults. Method: Cross-sectional analytical study. Administrative and clinical registries and questionnaire PES-Nursing Work Index from PHC nurses. Participants 44.214 diabetic patients in two health zones within the Community of Madrid, North-West Zone (NWZ) with higher socioeconomic situation and South-West Zone (SWZ) with lower socioeconomic situation, and their 507 reference nurses. Analyses were performed to multivariate multilevel logistic regression models. Primary outcome measure: Poor DM control (figures ≥ 7% HbA1c) Results: The prevalence of poor DM control was 40.1% [CI95%: 38.2-42.1]. There was a risk of 25% more of poor control if the patient changed centre and of 27% if changed of doctor-nurse pair. In the multilevel multivariate regression models: in SWZ increasing the ratio of patients over 65 years per nurse increased the poor control (OR=1.00008 [CI95%:1.00006-1.001]); and higher proportion of patients whose Hb1Ac was not measured at the centre contributed to poor DM control (OR=5.1 [CI95%:1.6-15.6]). In two models for health zone, the economic immigration condition increased poor control, in SWZ (OR=1.3 [CI95%:1.03-1.7]); and in NWZ (OR=1.29 [CI95%:1.03-1.6]). Conclusions: Higher 65 years old patients ratio per nurse, economic immigration condition and a higher proportion of patients whose Hb1Ac was not measured contribute to worse DM controlLos resultados presentados en este manuscrito forman parte de un proyecto financiado parcialmente por el Premio Nacional Marqués de Valdecilla (Santander) 2010 (12ª edición

Psychometric characteristics of the Spanish version of instruments to measure neck pain disability

[EN] Background. The NDI, COM and NPQ are evaluation instruments for disability due to NP. There was no Spanish version of NDI or COM for which psychometric characteristics were known. The objectives of this study were to translate and culturally adapt the Spanish version of the Neck Disability Index Questionnaire (NDI), and the Core Outcome Measure (COM), to validate its use in Spanish speaking patients with non-specific neck pain (NP), and to compare their psychometric characteristics with those of the Spanish version of the Northwick Pain Questionnaire (NPQ). Methods. Translation/re-translation of the English versions of the NDI and the COM was done blindly and independently by a multidisciplinary team. The study was done in 9 primary care Centers and 12 specialty services from 9 regions in Spain, with 221 acute, subacute and chronic patients who visited their physician for NP: 54 in the pilot phase and 167 in the validation phase. Neck pain (VAS), referred pain (VAS), disability (NDI, COM and NPQ), catastrophizing (CSQ) and quality of life (SF-12) were measured on their first visit and 14 days later. Patients' self-assessment was used as the external criterion for pain and disability. In the pilot phase, patients' understanding of each item in the NDI and COM was assessed, and on day 1 test-retest reliability was estimated by giving a second NDI and COM in which the name of the questionnaires and the order of the items had been changed. Results. Comprehensibility of NDI and COM were good. Minutes needed to fill out the questionnaires [median, (P25, P75)]: NDI. 4 (2.2, 10.0), COM: 2.1 (1.0, 4.9). Reliability: [ICC, (95%CI)]: NDI: 0.88 (0.80, 0.93). COM: 0.85 (0.75,0.91). Sensitivity to change: Effect size for patients having worsened, not changed and improved between days 1 and 15, according to the external criterion for disability: NDI: -0.24, 0.15, 0.66; NPQ: -0.14, 0.06, 0.67; COM: 0.05, 0.19, 0.92. Validity: Results of NDI, NPQ and COM were consistent with the external criterion for disability, whereas only those from NDI were consistent with the one for pain. Correlations with VAS, CSQ and SF-12 were similar for NDI and NPQ (absolute values between 0.36 and 0.50 on day 1, between 0.38 and 0.70 on day 15), and slightly lower for COM (between 0.36 and 0.48 on day 1, and between 0.33 and 0.61 on day 15). Correlation between NDI and NPQ: r = 0.84 on day 1, r = 0.91 on day 15. Correlation between COM and NPQ: r = 0.63 on day 1, r = 0.71 on day 15. Conclusion. Although most psychometric characteristics of NDI, NPQ and COM are similar, those from the latter one are worse and its use may lead to patients' evolution seeming more positive than it actually is. NDI seems to be the best instrument for measuring NP-related disability, since its results are the most consistent with patient's assessment of their own clinical status and evolution. It takes two more minutes to answer the NDI than to answer the COM, but it can be reliably filled out by the patient without assistanceS

Bladder cancer index: cross-cultural adaptation into Spanish and psychometric evaluation

BACKGROUND: The Bladder Cancer Index (BCI) is so far the only instrument applicable across all bladder cancer patients, independent of tumor infiltration or treatment applied. We developed a Spanish version of the BCI, and assessed its acceptability and metric properties. METHODS: For the adaptation into Spanish we used the forward and back-translation method, expert panels, and cognitive debriefing patient interviews. For the assessment of metric properties we used data from 197 bladder cancer patients from a multi-center prospective study. The Spanish BCI and the SF-36 Health Survey were self-administered before and 12 months after treatment. Reliability was estimated by Cronbach's alpha. Construct validity was assessed through the multi-trait multi-method matrix. The magnitude of change was quantified by effect sizes to assess responsiveness. RESULTS: Reliability coefficients ranged 0.75-0.97. The validity analysis confirmed moderate associations between the BCI function and bother subscales for urinary (r = 0.61) and bowel (r = 0.53) domains; conceptual independence among all BCI domains (r ≤ 0.3); and low correlation coefficients with the SF-36 scores, ranging 0.14-0.48. Among patients reporting global improvement at follow-up, pre-post treatment changes were statistically significant for the urinary domain and urinary bother subscale, with effect sizes of 0.38 and 0.53. CONCLUSIONS: The Spanish BCI is well accepted, reliable, valid, responsive, and similar in performance compared to the original instrument. These findings support its use, both in Spanish and international studies, as a valuable and comprehensive tool for assessing quality of life across a wide range of bladder cancer patients

Precisión de las clasificaciones clínicas

Se presentan tres generalizaciones del índice kappa para evaluar concordancia entre observadores. Las tres generalizaciones son: i) inclusión de diseños incompletos en el índice kappa basado en las definiciones explícitas de acuerdo para múltiples observadores, propuestas por Landis y Koch. Ii) inclusión de pesos que permitan ponderar la importancia relativa del desacuerdo entre distintas categorías, en el caso de múltiples observadores, para variables ordinales y acuerdo por pares. Iii) construcción de índices tipo kappa para otras definiciones de acuerdo. La tesis incluye, también la aplicación de los índices propuestos para evaluar el acuerdo entre médicos en tres estudios distintos sobre: 1) neuropatía periférica, cambios esclerodermiformes de la piel y contracturas articulares. 2) color del nevus flammeus y su aclaramiento por láser decolorante pulsado. 3) uso apropiado de la angioplastia coronaria transluminal percutáne

Generalization of the kappa coeficient for ordinal categorical data, multiple observers and incomplete designs

This paper presents a generalization of the kappa coefficient for multiple observers and incomplete designs. This generalization involves ordinal categorical data and includes weights which permit pondering the severity of disagreement. A generalization for incomplete designs of the kappa coefficient based on explicit definitions of agreement is also proposed. Both generalizations are illustrated with data from a medical diagnosis pilot study

Atlas of cancer mortality and other causes of death in Spain 1978-1992

Bilingüe: español-inglésEste nuevo Atlas pretende actualizar el anterior incluyendo un período de tiempo más amplio. Ello permite una mayor estabilidad de los indicadores de mortalidad, y su análisis dinámico facilita hacer predicciones a corto plazo. Asimismo, se han tratado de estudiar todas las localizaciones tumorales y otras causas de muerte superando las limitaciones de las listas reducidas de la CIE. Otra de las limitaciones del trabajo anterior era la utilización de un indicador (IME) que dificultaba la comparación interprovincial. Esto ha sido solucionado por el uso de ajustes por el método directo y estimadores relativos del efecto (razones de tasas) que además de ser comparables, mantienen las cualidades de interpretación intuitiva del IME.Introducción, Material y métodos, Guía para la lectura, Comentarios Bibliografía. Mapas de mortalidad por cáncer y otras causas, Anexo A. Tablas de resultados, Anexo B. Ajuste de tasas por edad, Anexo C. Análisis de la agregación, Anexo D. Modelos de regresión de Poisson, Anexo E. Edición de los resultados

Bladder cancer index : Cross-cultural adaptation into Spanish and psychometric evaluation

Background: The Bladder Cancer Index (BCI) is so far the only instrument applicable across all bladder cancer patients, independent of tumor infiltration or treatment applied. We developed a Spanish version of the BCI, and assessed its acceptability and metric properties. Methods: For the adaptation into Spanish we used the forward and back-translation method, expert panels, and cognitive debriefing patient interviews. For the assessment of metric properties we used data from 197 bladder cancer patients from a multi-center prospective study. The Spanish BCI and the SF-36 Health Survey were self-administered before and 12 months after treatment. Reliability was estimated by Cronbach's alpha. Construct validity was assessed through the multi-trait multi-method matrix. The magnitude of change was quantified by effect sizes to assess responsiveness. Results: Reliability coefficients ranged 0.75-0.97. The validity analysis confirmed moderate associations between the BCI function and bother subscales for urinary (r = 0.61) and bowel (r = 0.53) domains; conceptual independence among all BCI domains (r ≤ 0.3); and low correlation coefficients with the SF-36 scores, ranging 0.14-0.48. Among patients reporting global improvement at follow-up, pre-post treatment changes were statistically significant for the urinary domain and urinary bother subscale, with effect sizes of 0.38 and 0.53. Conclusions: The Spanish BCI is well accepted, reliable, valid, responsive, and similar in performance compared to the original instrument. These findings support its use, both in Spanish and international studies, as a valuable and comprehensive tool for assessing quality of life across a wide range of bladder cancer patients