Step 1 - Practice based pharmacist and medical review using database search for the following:

• Anti-parkinson drug therapy (excluding anticholinergic monotherapy).
• Disease codes to identify Parkinson's disease and parkinsonism, and exclude other diagnoses where anti-parkinson therapy may be used, although both are expected to be very small numbers (pituitary tumour, restless leg syndrome)
• To identify the duration of parkinsonism from the date of entry of the disease code.
• Pharmacy re-fill data to identify intermittent usage of treatment as an indicator of it being unlikely that the patient has idiopathic or dopa responsive parkinsonism.
• To identify patients on monotherapy with anti-parkinson therapy e.g. Selegiline for a prolonged duration as this is likely to suggest an alternative diagnosis.
• To record drug dosage over time, e.g. on an annual basis, again to identify whether patients fit in with the expected rates of change for degenerative parkinsonism where increasing combinations of drugs at higher doses are used over time.

Step 2 - Review of case records:

• Parkinson's disease nurse specialist and medical review of case records to identify additional clinical features of the condition and assist in identifying cases where it appears likely that anti-parkinson drug treatment is not helping the patient's condition.

Step 3 - Specialist out-patient review and follow-up:

• Invitation to the patient to attend the combined neurology/medicine for the elderly movement disorder clinic service where scoring against diagnostic clinical criteria would be undertaken, and where appropriate tapering of anti-parkinson therapy gradually under continued specialist observation.