Abstract
Background: Outcomes derived from longitudinal self-reported health-related quality of life measures can be confounded by response shift. This study was aimed to detect response shift phenomena among patients with hypertension attending a community-based disease management program. Methods: 240 consecutive consulting or followed up patients with diagnosed hypertension were recruited. The SF-36 instruments were self-administered at 12 community health service stations and four weeks after attending the program. RS was assessed by the 4-step structural equation modeling approach. Results: Data from 203 (84.6%) patients were eligible for analyses (mean age 65.9±10.8 years, 46,3% female). The results showed uniform recalibration of social functioning ( X2SBdiff(1)=22.98, P<0.001), and non-uniform recalibration of role limitations due to physical problems ( X2SBdiff(1)=8.84, P=0.003), and bodily pain ( X2SBdiff(1)=17.41, P<0.001). The effects of response shift were calculated as “small”, but the influence on the measurement results was noticeable. After accounting for the response shift effect, the general physical health of participants was improved (+0.234, P<0.001), while a deterioration of general mental health (-0.165, P=0.025) was also found. Conclusions: Recalibration existed among patients with hypertension attending the disease management program. The adaptation to chronic illness might act as a catalyst that induced the response shift. We concluded that response shift should be considered in hypertension researches with longitudinal health-related quality of life data, and linking with measurement of the appraisal process was recommended.
Assessment of Response Shift and True Change Using Structural Equation Modeling for Health–Related Quality-of-Life Scores in Patients with Breast Cancer After Surgery
