[Does your patient take his medicine? Compliance problems in clinical practice]

There is convincing evidence from compliance research that deviations from the prescribed drug regimen is the rule rather than the exception. Demographic and psychosocial patient factors poorly correlate with non-compliance, whereas features of the disease, mechanisms of treatments, regimens and the patient physician interaction are particularly important determinants of patients' compliance behaviour. Non-compliance can not be predicted. There are problems in the assessment of non-compliance, more particularly of its clinical consequences. New microprocessor-based technology evaluated essential insight into patients' compliance behaviour and revealed different patterns of non-compliance. On one hand, the therapeutic outcome can be impaired by non-compliance, on the other hand, however, certain patterns of non-compliance appear to be appropriated from the patients' point of view. In medical practice it is important to consider non-compliance as essential impact on drug therapy and to promote the discussion of this issue with patients.