RESUMO
BACKGROUND: The Dermatology Life Quality Index (DLQI) is the most commonly used instrument for clinical evaluation of the impact on health-related quality of life (HRQOL) in dermatological research protocols. The DLQI's classical psychometric properties have been considered adequate in validation studies from several countries. However, the structure of the DLQI is a matter of discussion, especially concerning the dimensionality and informative properties of its questions according to the item response theory (IRT). METHODS: Pooled data from studies in Brazil that utilized the DLQI to assess HRQOL in 14 dermatoses were reanalyzed. Classical psychometrical analysis, dimensionality assessment through parallel analysis and IRT (Samejima's ordinal model) analysis were performed. RESULTS: The sample consisted of 1286 patients with a mean age of 47 years (SD = 16), and the proportion of women was 59% (765). The DLQI scores ranged from 0 to 29, with a median (p25-p75) of 5 (2-11). All items indicated significant correlations with the total DLQI score (rho > 0.54). The Cronbach's alpha result was 0.90 (CI 95% 0.89-0.91). Parallel analysis indicated a unidimensional factor structure. According to IRT analysis, items q6 (sports) and q7 (work/study) exhibited insufficient fit to the model (p < 0.01), while the items that indicated the best discrimination and information functions were q2 (embarrassment), q3 (shopping/gardening), q4 (clothing) and q5 (social/leisure). The ordination of the scores was confirmed for all items. Most items revealed non-uniform behavior according to sex, age and type of disease. CONCLUSIONS: The DLQI exhibits adequate psychometric reliability and a unidimensional structure for assessing HRQOL in Brazilian dermatological patients. The DLQI's performance varies in the assessment of HRQOL in heterogeneous samples.
Assuntos
Qualidade de Vida , Dermatopatias/psicologia , Inquéritos e Questionários/normas , Adulto , Brasil , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Psicometria/instrumentação , Reprodutibilidade dos TestesRESUMO
CONTEXT: In advanced cancer, although performance status (PS), systemic inflammatory response and nutritional status are known to have prognostic value, geographical variations and sociodemographic indexes may also impact survival. OBJECTIVES: This study compares validated prognostic factors in two international cohorts and establishes a prognostic framework for treatment. METHODS: Two international biobanks of patients (n=1.518) with advanced cancer were analyzed. Prognostic factors (Eastern Cooperative Oncology Group Performance Status [ECOG-PS], body mass index [BMI] and modified Glasgow Prognostic Score [mGPS]) were assessed. The relationship between these and survival was examined using Kaplan-Meier and Cox regression methods. RESULTS: According to multivariate analysis, in the European cohort the most highly predictive factors were BMI <20 kg/m2 (hazard ratio [HR] 1.644), BMI 20-21.9 kg/m2 (HR 1.347), ECOG-PS (HR 1.597-11.992) and mGPS (HR 1.843-2.365). In the Brazilian cohort, the most highly predictive factors were ECOG-PS (HR 1.678-8.938) and mGPS (HR 2.103-2.837). Considering gastrointestinal cancers in particular (n=551), the survival rate at 3 months in both cohorts together ranged from 93% (mGPS 0, PS 0-1) to 0% (mGPS 2, PS 4), and from 81% (mGPS 0, BMI >28 kg/m2) to 44% (mGPS 2, BMI <20 kg/m2). CONCLUSION: The established prognostic factors that were compared had similar prognostic capacity in both cohorts. A high ECOG-PS and a high mGPS as outlined in the ECOG-PS/mGPS framework were consistently associated with poorer survival of patients with advanced cancer in the prospective European and Brazilian cohorts.