PUBLIC doctors frustrated with rocketing insurance premiums are drawing up their own plans for cheaper, more comprehensive coverage. The concern was sparked by recent court cases involving doctors, including one case of plagiarism at the University of Hong Kong, for which the losing party had to pay costs. The Public Doctors' Association said its members were fed up with subsidising private doctors in the two existing schemes, although their own separate insurance package was still some way off. Association president Dr Chu Kin-wah said: ''Recent court cases have seen insurance premiums rise dramatically and it seems that the trend is likely to continue. ''But most of the claims come from private doctors and so it really is time that public doctors had a scheme of their own with good coverage at reasonable rates.'' At the moment the Medical Protection Society offers public and private doctors insurance for about $4,000 a year, while the Medical Defence Union's policy costs about $10,000 a year compared with just over $2,000 five years ago. ''The high [union] premium is largely due to the plagiarism case at the University of Hong Kong, but it will only take one more case like that to take the [society] premium to a similar level,'' Dr Chu said. Hong Kong University's Dr Lam Tai-hing was found guilty of copying a questionnaire drawn up by Dr Linda Koo Chih-ling and Professor John Ho Hung-chiu for their research into lung cancer in non-smoking Chinese women. The two schemes have refused to offer lower premiums to public doctors, so the association is trying to agree on a different policy with another insurance company. Under the scheme being negotiated at the moment, subscriptions from just 500 public doctors will result in a premium of about $2,000 a year, while between 2,000 and 3,000 subscribers will bring the cost down to about $1,500 each. But the association says it has run into a major stumbling block in the talks. ''The package on offer at the moment only covers doctors while they are working in the Hospital Authority (HA) and not after they have left,'' said Dr Chu. ''Court cases are often heard many years after the event and so the negotiations for extended coverage are of crucial importance.'' Most public doctors are insured not only under the authority's scheme but also under one of the two individual schemes available. ''The problem is that the HA scheme only covers service-related claims which is simply not adequate,'' Dr Chu said. ''What public doctors need is their own individual scheme which covers what the HA scheme doesn't cover so they no longer have to subsidise private doctors.'' The association is consulting legal advisers in an effort to reach agreement with the insurance company concerned. Dr Chu added: ''There are still a lot of things that have to be considered carefully but if we can drastically cut the insurance premiums which public doctors have to pay then it will be worthwhile.''