Quality of life researchers have been studying "response shift" for a decade now, in an effort to clarify how best to measure QoL over time and across changing circumstances. However, we contend... Show moreQuality of life researchers have been studying "response shift" for a decade now, in an effort to clarify how best to measure QoL over time and across changing circumstances. However, we contend that this line of research has been impeded by conceptual confusion created by the term "response shift", that lumps together sources of measurement error (e.g., scale recalibration) with true causes of changing QoL (e.g., hedonic adaptation). We propose abandoning the term response shift, in favor of less ambiguous terms, like scale recalibration and adaptation. Show less
The formative evaluation of a standardized psychosocial education program for patients with Parkinson's disease (PD) and their caregivers. The results of the participation of the caregivers are... Show moreThe formative evaluation of a standardized psychosocial education program for patients with Parkinson's disease (PD) and their caregivers. The results of the participation of the caregivers are presented next to the data of the patients. Caregivers (n = 137) and patients with PD (n = 151) participated in the 8-week program in separate groups. Measurements were performed on psychosocial problems (BELA-P/A-k), health state (EQ-5D VAS), quality of life (PDQ-39) and depression (SDS) 1 week before and 1 week after the program. Participants rated their mood on a visual analogue scale before and after each session, and they filled in an evaluation questionnaire after the last session. Scores on the BELA-P/A-k improved significantly on the 'bothered by scale' as well as the 'need for help scale'. No improvements were found on EQ-5D VAS, PDQ-39 and SDS. Mood ratings improved significantly after each session. Most participants evaluated the program as positive. Feedback led to improvements in the program, which are incorporated in a final manual. The program was feasible to run in the different countries. This exploratory study led to improvements in the program and recommendations for further research. A study on the effectiveness of the program is the next step. Show less
Post, W.J.; Buijs, C.; Stolk, R.P.; Vries, E.G.E. de; Cessie, S. le 2010
The analysis of longitudinal health-related quality of life measures (HRQOL) can be seriously hampered due to informative drop-out. Random effects models assume Missing At Random and do not take... Show moreThe analysis of longitudinal health-related quality of life measures (HRQOL) can be seriously hampered due to informative drop-out. Random effects models assume Missing At Random and do not take into account informative drop-out. We therefore aim to correct the bias due to informative drop-out. Analyses of data from a trial comparing standard-dose and high-dose chemotherapy for patients with breast cancer with respect to long-term impact on HRQOL will serve as illustration. The subscale Physical Function (PF) of the SF36 will be used. A pattern mixture approach is proposed to account for informative drop-out. Patterns are defined based on events related to HRQOL, such as death and relapse. The results of this pattern mixture approach are compared to the results of the commonly used random effects model. The findings of the pattern mixture approach are well interpretable, and different courses over time in different patterns are distinguished. In terms of estimated differences between standard dose and high dose, the results of both approaches are slightly different, but have no consequences for the clinical evaluation of both doses. Under the assumption that drop-out is at random within the patterns, the pattern mixture approach adjusts the estimates to a certain degree. This approach accounts in a relatively simple way for informative drop-out. Show less
Stiggelbout, A.M.; Putter, H.; Marijnen, C.A.M.; Klein-Kranenbarg, E.; Velde, C.J.H. van de 2005