HEDS is part of the School of Health and Related Research (ScHARR) at the University of Sheffield. We undertake research, teaching, training and consultancy on all aspects of health related decision science, with a particular emphasis on health economics, HTA and evidence synthesis.

Thursday, 21 October 2010

Sample size supported by pre-trial modelling

Renal physicians in Sheffield want to examine the use of 3 doses of cinacalcet per week instead of the typical 7 doses for the treatment of secondary hyperparathyroidism in patients with end-stage renal disease on maintenance dialysis therapy.  The daily dose was not deemed cost-effective in a NICE technology appraisal, but at 3/7th the cost, three doses may well be.  When designing the trial we used PenTAG’s model to assess the probability that the three dose regime would be cost-effetive given different hypothesised efficacies and samples sizes (which defined the standard errors around efficacy).  From a baseline result of £61,806 within the technology appraisal, a sample size of 30 per arm in the proposed trial and with 80% efficacy of the daily dose produces a 65% chance of treatment being cost-effective.  A four-fold increase in sample size increases this to 68%, suggesting that a much larger trial may not be worthwhile.

Contact Simon Dixon or Mike Holmes for further details.