Conclusions

CONCLUSIONS

PEM in NZ, like PEM in the UK, is a valuable method of post-marketing surveillance. The method-ology of PEM is particularly useful for the calculation of rates of adverse events, as exposure is defined from prescription data. This information is of great value to patients and doctors when evaluating the bene-fits and harms of medicines. The additional value of data collected in PEM studies is that it is derived from ‘real-life’ use of medicines. The populations studied are generally more representative of normal clinical practice, without the exclusion criteria of pre-marketing clinical trials.

The NZ IMMP has adapted and enhanced PEM to perform many different pharmacoepidemiology stud-ies. The intensive methodology, where adverse events are identified from multiple sources, has been effec-tive for signal identification. The symbiotic relation-ship of the IMMP with the national spontaneous reporting programme has enhanced signal identifica-tion in NZ.

Once cohorts are established, follow-up may be conducted in the whole population or in specific subgroups. Studies to further investigate signals iden-tified or specific safety issues may be conducted, and examples of these studies have been given in this chapter. The range of investigations conducted by the IMMP shows that the methodology of PEM in NZ is highly adaptable.

There is much potential to further enhance the methodology of the IMMP. Electronic capture of prescription data may enable cohorts to be established in a shorter time, although this would require addi-tional funding to set up. There is also scope to investi-gate different methods for identifying events, and this is already in progress with the record-linkage studies that have been initiated. In the future, it is hoped that the IMMP will be able to continue to develop and enhance these methodologies.

Internationally there is scope for PEM methodol-ogy to be used much more widely, and pooled infor-mation from several centres would provide added value. Countries struggling to obtain a ‘worthwhile’ number of reports from their spontaneous reporting programmes could switch resources to PEM studies of a few selected drugs. Countries with a large popu-lation who feel unable to mount a national scheme could use the method regionally.

In recent times, medicines regulatory authorities worldwide have announced that all new medicine applications will require a post-marketing phar-macovigilance plan to be submitted at the time of first evaluation (http://www.fda.gov.cder/guidance/ 6355fnl.htm). In Australasia – where plans for phar-macovigilance in the new Joint Tasman Agency are currently under discussion – it is possible that this proposal will also be adopted. The IMMP, using the methods described in this chapter, has much to offer in performing targeted post-marketing surveil-lance studies in this new environment. Although NZ has a population of only 4 million people, the IMMP has produced results that have made a signif-icant contribution to pharmacovigilance worldwide. The enhanced and adapted PEM methodology of the NZ IMMP should continue to be an important component of the pharmacovigilance toolbox of the future.