Clinical trials provide the most reliable evidence to determine which treatments benefit patients. However, randomised trials are logistically difficult to undertake and very expensive. During this fellowship I will take two strategies to improve the cost-effectiveness of clinical trials in New Zealand. First, to piggy back studies on large, funded international clinical trials. Second, to promote collaborations to undertake randomised registry trials - an innovative method which allows randomised comparison of two 'accepted' treatments as part of usual care.