Disruption in time projection and non-adherence to long-term therapies

Patients' non-adherence to medical prescriptions is a crucial issue in contemporary medicine because it can jeopardize care efficacy. Non-adherence is especially frequent in patients with chronic diseases. In this article, we propose that a particular condition, which we call disruption in time projection, is a cause of non-adherence to medication therapies in chronic diseases.

A questionnaire was administered to 120 hospitalized people with type 2 diabetes addressing three psychological constructs defining time projection: patience/impatience in a fictive monetary scenario (preferring to receive €1,500 in 1 year or €500 today), magnitude of temporal horizon (greater or lesser ability to imagine future events) and perception of the degree of physical similarity of current self to self at 1 year, 5 years and 10 years from the present. In addition, the questionnaire evaluated adherence to medication, social deprivation and depression.

In the multivariate analyses, two factors were associated with adherence to medication: patience (P<0.001) and long temporal horizon (P=0.006). Two factors were associated with HbA1c ≥8% (64 mmol/mol): non-adherence to medication (P=0.003) and short temporal horizon (P=0.011). Three factors were associated with long temporal horizon: adherence to medication (P<0.001), patience (P<0.001) and the existence of grandchildren (P=0.002). Social deprivation (P<0.001), non-adherence (P<0.001), female gender (P=0.002) and short temporal horizon (P=0.050) were associated with impatience. Finally, an association of adherence to expected similarity in the future to current self, impatience, short temporal horizon, social deprivation and depression was also shown in a multiple correspondence analysis.

What we termed a disruption in time projection may be a unique determinant for non-adherence to long-term therapy and, therefore, may influence the outcome of chronic diseases. We hypothesize that this is involved in both intentional and unintentional non-adherence and that it represents the loss of a protective mechanism. If this novel concept is to be confirmed in other settings and generalized to other chronic diseases, the recognition of its role in disease prognosis may help orient the teaching and practice of medicine.