Response Shift and Quality of Life in Patients Suffering From Schizophrenia and Their Caregivers

Quality of life (QoL) measurements have become an important way to evaluate the treatments and care provided to patients with schizophrenia. Understanding determinants of QoL in schizophrenia is of importance for developing effective interventions that would improve patient functional and subjective well-being. A challenge in the interpretation of QoL measures, especially in longitudinal studies, is that QoL is self-reported by the patient and might be influenced by psychological phenomena such as adaptation to illness. An important mediator of this adaptation process is a "response shift" (RS), which involves changing internal standards, values and the conceptualization of QoL. RS can be divided into three phases 1) reconceptualization (i.e., a redefinition of QoL), 2) reprioritization (i.e., a change in the importance attributed to component domains constituting QoL) and 3) recalibration (i.e., a change in a patient's internal standards of measurements). Patients may change their frame of reference, rendering scores from different measurement occasions incomparable. An RS is a potential explanation when the QoL of an individual who has experienced a serious health event or chronic condition is similar to the QoL of a healthy individual. With an RS, the concept of QoL changes over time and cannot be compared longitudinally because of changes in internal standards, values, and/or concepts. True change may be over- or underestimated when a RS is present, leading to biased estimates of the magnitude of change.The objective is to examine whether a response shift, a change in the internal standards of a patient, occurs in patients suffering from schizophrenia and in their caregivers.

This is a monocentric and propective design study, with inclusion of patients and caregivers on a 12-month period, and a follow up on a 12-month period.

100 patients with schizophrenia and 100 caregivers

Test approach (Response shift (RS) (pre-test - then-test), unadjusted effect (post-test - pre-test), and adjusted effect (post-test - then-test scores)) will be completed with other statistical approaches such as confirmatory factorial analysis, multilevel models and CART method.