What is the value of social values? The uselessness of assessing health-related quality of life through preference measures

BACKGROUND: The use of preference-based measures in the evaluation of health outcomes has extended considerably over the last decade. Their alleged advantage over other types of general instruments in the evaluation of health related quality of life (HRQOL), supposedly lies in the fact that preference measures incorporate values or utilities that reflects the value of social preferences through health states. The objective of this study was to determine whether the use of social preference weights or utilities makes any real difference when calculating scores for the Euroqol (EQ5-D) questionnaire, a HRQOL preference-based measure. METHODS: Responses to the EQ5-D of a sample of 10,972 patients from 10 countries enrolled in an observational study of the treatment of schizophrenia in Europe were used for this purpose. Two different methods of scoring the EQ-5D where compared: 'weighting the items' of the questionnaire through the UK official weight coefficients, and 'non-weighting the items'. Pearson's, Spearman's, and two-way mixed parametric intraclass correlation coefficients were used to estimate the association of the scores obtained in both ways. RESULTS: The association between weighted and unweighted Euroqol scores was extremely high (Pearson's r = 0.91), as was the association between their ranks (Spearman's ρ = 0.93). The intraclass correlation coefficient obtained (0.89) also suggested that the concordance between the score distributions was prominent. CONCLUSIONS: A non-weighted approach to score the EQ5-D is enough to explain a high proportion of variance in scores obtained through the use of utilities. The differential contribution of weights based on population preference values is therefore minimal and, in our opinion, negligible

Dexmedetomidine vs midazolam or propofol for sedation during prolonged mechanical ventilation: two randomized controlled trials.

CONTEXT: Long-term sedation with midazolam or propofol in intensive care units (ICUs) has serious adverse effects. Dexmedetomidine, an α(2)-agonist available for ICU sedation, may reduce the duration of mechanical ventilation and enhance patient comfort. OBJECTIVE: To determine the efficacy of dexmedetomidine vs midazolam or propofol (preferred usual care) in maintaining sedation; reducing duration of mechanical ventilation; and improving patients' interaction with nursing care. DESIGN, SETTING, AND PATIENTS: Two phase 3 multicenter, randomized, double-blind trials carried out from 2007 to 2010. The MIDEX trial compared midazolam with dexmedetomidine in ICUs of 44 centers in 9 European countries; the PRODEX trial compared propofol with dexmedetomidine in 31 centers in 6 European countries and 2 centers in Russia. Included were adult ICU patients receiving mechanical ventilation who needed light to moderate sedation for more than 24 hours (midazolam, n = 251, vs dexmedetomidine, n = 249; propofol, n = 247, vs dexmedetomidine, n = 251). INTERVENTIONS: Sedation with dexmedetomidine, midazolam, or propofol; daily sedation stops; and spontaneous breathing trials. MAIN OUTCOME MEASURES: For each trial, we tested whether dexmedetomidine was noninferior to control with respect to proportion of time at target sedation level (measured by Richmond Agitation-Sedation Scale) and superior to control with respect to duration of mechanical ventilation. Secondary end points were patients' ability to communicate pain (measured using a visual analogue scale [VAS]) and length of ICU stay. Time at target sedation was analyzed in per-protocol population (midazolam, n = 233, vs dexmedetomidine, n = 227; propofol, n = 214, vs dexmedetomidine, n = 223). RESULTS: Dexmedetomidine/midazolam ratio in time at target sedation was 1.07 (95% CI, 0.97-1.18) and dexmedetomidine/propofol, 1.00 (95% CI, 0.92-1.08). Median duration of mechanical ventilation appeared shorter with dexmedetomidine (123 hours [IQR, 67-337]) vs midazolam (164 hours [IQR, 92-380]; P = .03) but not with dexmedetomidine (97 hours [IQR, 45-257]) vs propofol (118 hours [IQR, 48-327]; P = .24). Patients' interaction (measured using VAS) was improved with dexmedetomidine (estimated score difference vs midazolam, 19.7 [95% CI, 15.2-24.2]; P < .001; and vs propofol, 11.2 [95% CI, 6.4-15.9]; P < .001). Length of ICU and hospital stay and mortality were similar. Dexmedetomidine vs midazolam patients had more hypotension (51/247 [20.6%] vs 29/250 [11.6%]; P = .007) and bradycardia (35/247 [14.2%] vs 13/250 [5.2%]; P < .001). CONCLUSIONS: Among ICU patients receiving prolonged mechanical ventilation, dexmedetomidine was not inferior to midazolam and propofol in maintaining light to moderate sedation. Dexmedetomidine reduced duration of mechanical ventilation compared with midazolam and improved patients' ability to communicate pain compared with midazolam and propofol. More adverse effects were associated with dexmedetomidine. TRIAL REGISTRATION: clinicaltrials.gov Identifiers: NCT00481312, NCT00479661

Qualidade de vida e saúde: aspectos conceituais e metodológicos Quality of life and health: conceptual and methodological issues

O conceito qualidade de vida tem suscitado pesquisas e cresce a sua utilização nas práticas desenvolvidas nos serviços de saúde, por equipes profissionais que atuam junto a usuários acometidos por enfermidades diversas. O presente artigo tem como objetivo descrever a evolução histórica e tecer algumas considerações sobre aspectos conceituais e metodológicos do conceito qualidade de vida (QV) no campo da saúde. Baseando-se na revisão da literatura, dois aspectos do termo são destacados no plano conceitual: subjetividade e multidimensionalidade. Quanto aos aspectos metodológicos, uma tendência significativa tem sido a construção e/ou adaptação de instrumentos de medida e de avaliação da QV. Conclui-se que os esforços teórico-metodológicos têm contribuído para a clarificação e relativa maturidade do conceito. Trata-se de um construto eminentemente interdisciplinar, o que implica a contribuição de diferentes áreas do conhecimento para o seu aprimoramento conceitual e metodológico. Sua utilização, portanto, pode contribuir para a melhoria da qualidade e da integralidade da assistência na perspectiva da saúde como direito de cidadania.<br>The quality of life (QL) concept has led to extensive scientific research and has been increasingly used by health care professionals treating a wide range of diseases. This paper addresses the historical use of the concept and specific issues linked to conceptual and methodological aspects of the QL construct within the health care context. Reviewing the literature, two aspects stand out: subjectivity and multidimensionality. In the methodological field, the construction and/or adaptation of QL measurement instruments appear as a significant trend. Theoretical and methodological efforts have helped clarify and improve the concept's adequacy. The QL construct is definitely interdisciplinary, encompassing contributions by different areas of knowledge and research, thereby improving its conceptual and methodological potential as a research instrument. Therefore, use of the concept can actually help improve both the quality and the integrated, multidimensional nature of health care from a perspective that views the latter as a basic citizen's right