SPECIALIST medical treatment requiring intensive care from nurses has contributed to the staff shortage, a senior Hospital Authority official said. Hong Kong had more nurses per capita than many regional countries, said Hospital Authority senior executive manager (Nursing) Susie Lum Shun-sui. There are 4.85 nurses for every 1,000 people in the territory, compared with 3.18 in Singapore 3.18, 2.08 in Korea, and 1.9 in Taiwan. ''Hong Kong, for example, has put more weight on the provision of high-tech medical treatment like the establishment of heart treatment centre, or cancer clinics. Those specialist services demand intensive care from nurses. A one-to-one nurse-client ratio often is needed to support such services,'' Miss Lum said.