A response shift reflects a change in perception about one's own condition that may arise from:
(1) recalibration: change in the internal standard (benchmark)
(2) reevaluation and reprioritization: change in personal values
(3) reconceptualization: change in definition
Some patients have no response shift.
Some patients will show a more positive shift in response.
Some patients will show a more negative shift in response.
For example, a response shift may cause a patient with a chronic disease to be more positive about an outcome despite an objective deterioration in overall health because the person has adapted to and accepted the new situation.
A common assumption is that a person will respond in the same way before and after an intervention, with the intervention being the only thing to change. In actuality both the condition and the patient may change, and do so in unpredictable ways.