To identify the minimally important difference (MID) of the EQ‐5D‐3L and determinants of change in quality of life (QoL) as measured by the EQ‐5D‐3L over 1 year for Chinese type 2 diabetic patients (T2DPs).
Clinically diagnosed T2DPs were recruited from 66 community health centres in five Chinese cities using a multistage quota sampling method between December 2010 and October 2011. Demographics, diabetes‐related information, and health‐related behaviours were collected at baseline. The EQ‐5D‐3L was administered at baseline and at 12 months. Anchor‐based and distribution‐based approaches were employed to estimate MIDs. Using the MIDs as cut‐points, we identified the change in EQ‐5D‐3L‐measured QoL into “worsening,” “no change,” and “bettering.” Logistic and ordered logistic regressions were conducted for those who reported best possible EQ‐5D health state (“best possible HS”) and impaired EQ‐5D health states (“impaired HS”) at baseline, respectively. Explanatory variables included demographics, diabetes‐related information, and health‐related behaviours.
A total of 1958 patients (54.9% female, mean age 61.2 years, mean diabetes duration 7.9 years) were included in our analysis. MIDs of the EQ‐5D‐3L for deterioration and improvement were estimated as −0.066 to −0.003, and 0.049 to 0.077, respectively. For the impaired HS group, older age, lower education, and less exercise were significant predictors for worsening in QoL; whereas, those predictors were older age, female gender, and lower income for the best possible HS group.
Minimally important differences for deterioration and improvement were estimated for the EQ‐5D‐3L. Age, gender, education, income, and exercise were significant determinants of QoL change for Chinese T2DPs.