Study of Comprehension and Execution of Medication Prescriptions in Parkinsonian Patients and Healthy Volunteers

Many Pd patients are non-adherent to their treatments. Because Pd patients are generally over 60 years old, suffer from cognitive disorders, and have complex medication regimens, taking medications as prescribed is a too complex cognitive task for them. It supposes the ability to understand the prescription, to plan and memorize the actions to carry out and to remember them while executing them. As prescriptions are communicated to patients via procedural documents, it should be possible to improve patient's comprehension by using a format suitable for their needs and characteristics. Previous studies with elderly people suggest that the table format is more effective than the textual format. However no study addressed this question with Pd patients. One-hundred and twenty patients with Parkinson's disease and 120 healthy volunteers participate voluntarily to the study. Their task consists in reading on a touch screen, or on a tablet, two fictive medication prescriptions. One is presented in a table format and the other in a textual format. Each prescription comprises two regular medications (same doses and moments of the day) and two irregular medications (different doses or different moments). For each prescription, participants must fill a virtual pillbox displayed on the screen as prescribed in the prescription. Prescriptions and pillboxes are displayed by a tablet software specifically designed to record in real time all participant's actions and related chronometric data. Half participants perform the task in the " tablet condition ", and the other half in the " touch-screen " condition. In the touch-screen condition an eye-tracker is used to record eye fixations and scanpaths in real time. Once the 2nd pillbox filling is finished a battery of cognitive tests and questionnaires is administered to participants to identify Pd subtypes of impaired performances. The main hypothesis predicts an effect of the format of prescriptions. More precisely, it consists in two concurrent hypotheses. H1a (the mental model model hypothesis): the table format should facilitate the pillboxes filling in the parkinsonian group and in the healthy volunteer group by facilitating the elaboration of an accurate mental model. H1b (the working memory load hypothesis): because parkinsonian patients are frequently impaired in visuospatial tasks, the tabular format could have no effect or could have a negative effect only in this group. A correlation between cognitive subtypes identified by cluster analyses and task performances is expected. Several secondary hypotheses will be tested.