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Annual Report 2017 17

A large part of the Institute’s work is

devoted to Parkinson’s disease. Although

we have a lot of clinical and research

expertise in working directly with people

with this condition, surprisingly little had

been learned about the wider picture of

Parkinson’s in this country.

n 1966, at the beginning of their careers, distinguished neurologists
I Martin Pollock and Richard Hornabrook reported the first local
estimates of the epidemiology of Parkinson’s. This was a landmark

paper internationally, being one of the first to highlight the high
rate of dementia in what was previously thought to be solely a

movement disorder. The study was, however, restricted to residents
of Wellington, and the only Ma¯ori patients they identified were rural-
dwellers and hence were not included.

A later study in 1992 was similarly limited to the city of Dunedin.
An authoritative national estimate of the frequency of Parkinson’s

was sorely needed, as international estimates are unlikely to
generalise to our unique population. Dr Toni Pitcher has led this
research, collaborating closely with biostatistician, Dr Daniel Myall.

They applied a “big data” approach, analysing literally millions
of prescribing records over a decade, cross-referenced to other
national and regional data sources. They estimated for the first time

the national prevalence (the number of people with the disease:
191 per 100,000 people), and the incidence (the rate of new cases:
29 per 100,000 people per year).

The risk of Parkinson’s increases dramatically with age, although
most previous studies have not directly examined beyond the age of

85. By being able to cover an entire national population, we could
give reliable rates up to age 100, and produced strong confirmation