Importance of sociodemographic and morbidity aspects in measuring health-related quality of life: performances of three tools

Abstract

Background Since health-related quality of life (HRQL) measures are numerous, comparisons have been suggested. Aim To compare three HRQL measures: SF6D, HUI3 and EQ5D. Methods Three questionnaires (SF36, HUI3, EQ5D) were administered to 1,011 patients attending 16 general practices in two Italian cities. Information about patients' gender, age, education, marital status, smoking, body mass index (BMI) and chronic diseases (hypertension, diabetes, cardiovascular and musculoskeletal diseases) were also collected. Questionnaires scores were calculated using the appropriate algorithms; in particular SF6D scores were obtained from SF36 items. Agreement and correlation between questionnaires scores were investigated using Bland and Altman method and Spearman coefficient. The influence of sociodemographic and morbidity indicators on scores was analysed using the nonparametric quantile regression. Results The Spearman coefficient was about 0.6 for all questionnaires. The 95% limits of agreement of the scores were approximately from -0.5 to 0.3 except for SF6D and EQ5D when they were from -0.4 to 0.2. The measures were influenced by socio-demographic and clinical variables in a similar way, especially SF6D (the index obtained from SF36) and EQ5D, which appeared to be influenced by the same pattern of factors, including gender, chronic diseases, smoking and BMI. Conclusions Overall, the agreement between questionnaires scores was quite low, whilst the correlation level was good. Questionnaire scores were influenced by sociodemographic and clinical variables in a similar way, especially SF6D and EQ5D. Therefore, the descriptive capacity of SF6D and EQ5D was found to be similar.

Comparing the Performance of the SF-6D and the EQ-5D in Different Patient Groups

“…This result was expected, since (almost) all studies report that EQ-5D suffers from ceiling effect whatever the type of population (in general, healthy, suffering from specific diseases, younger, older, etc.). 1,4,14,17,47,58 In fact, for the mobility, self-care and usual activities dimensions, more than 60% of asthma, COPD and cataracts patients responded at level 1 (no limitations). Moreover, in the pain/discomfort and anxiety/ depression dimensions, more than 60% of asthma and COPD patients responded at level 1 (no limitations), and about more than half of cataracts patients and more than three quarters of RA patients responded at level 2 (some limitations).…”

“…However, although these instruments all have these characteristics, many researchers have detected discrepancies in the utility values obtained by different instruments, mainly due to differences of the descriptive part of the measure. Indeed, an analysis of some of the studies published in recent years in the area of health economics and the measurement of HRQoL, [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] including studies with a wide diversity of populations and interventions, shows only a weak or moderate level of agreement between different preferencebased instruments.…”

Changes in Health Utility of Patients after Cardiac Surgery

“…The SF-6D was developed as a practical tool for obtaining a preferencebased index from SF-36 data [16,17]. First, we assessed the patients with the SF-36.…”

“…First, we assessed the patients with the SF-36. The SF-6D questionnaire was developed to obtain health utility from the SF-36 questionnaire for use in health economic evaluations and links between psychometric and preference/utilitybased measures [16,17]. No limitation in any of the dimensions means no subtraction from the baseline value of 1.0, i.e., perfect health [16,17].…”

“…No limitation in any of the dimensions means no subtraction from the baseline value of 1.0, i.e., perfect health [16,17]. The higher the limitation in each domain, the higher the subtraction from the baseline [16,17]. After assessment with the SF-36, SF-36 scores were converted to mean SF-6D utility scores by iHope International (iHope International., Co. Ltd., Kyoto, Japan) based on work in previous studies [10,12,13].…”