The reported scale of repeat prescriptions ranges from 29% to 75% of all items prescribed, depending on the definition of repeat prescribing and other variables. It is likely that a substantial part of repeat prescribing by general practitioners (GPs) occurs without direct doctor-patient contact. While this reduces the workload for the GP and is convenient for the patient, it does not provide the adequate control that is needed to ensure that every repeat prescription is still appropriate, effective and well tolerated, and that it is still being viewed upon and taken by the patient as intended. Infrequent therapy reviews may lead to failure to prevent, identify and solve drug-related problems and drug wastage, and may, thereby, have a negative impact on the effectiveness, safety or cost of the medications prescribed.
Studies evaluating the repeat prescribing process have shown that GPs and medical practices vary widely in their degree of administrative and clinical control of repeat prescriptions. Contrary to the opinion that GPs cannot change prescribing behaviour when the prescription is initiated by a medical specialist, GPs have their own responsibility for controlling the repeats of such prescriptions.
Intervention studies suggest that a medication review by a pharmacist can help to reduce drug-related problems with repeat prescriptions, and the effectiveness of the intervention may be increased by combining the medication review with a consultation of the patient's medical records and a patient interview. In several studies, such an intervention was relatively inexpensive and, therefore, feasible. However, these conclusions should be viewed with appropriate caution because a number of caveats pertain. There is still no evidence that these types of intervention improve health-related quality of life or reduce healthcare cost, and so far only a few trials have produced any evidence of clinical improvement. As implicit and explicit screening criteria have their own benefits and limitations, a combined application may offer a more thorough assessment but may also be more complex and time consuming.
Further studies on the development and evaluation of repeat prescription management models are needed, preferably focussing on improving clinical, humanistic and economic outcomes. New studies should investigate the effects of: different types of interventions; different organisational models; different target populations; and selecting and training different types of healthcare professionals. Future studies should also assess whether results are sustained, the optimal time interval between reviews of repeat prescriptions, and the possibilities offered by new computerised support technologies.