@misc{9650,
  author = {A. Dregan and A. Grieve and T. Van Staa and M. Gulliford},
  title = {Potential application of item-response theory to interpretation of medical codes in electronic patient records},
  year = {2011},
  journal = {BMC Med Res Methodol},
  volume = {11},
  pages = {168},
  issn = {1471-2288},
  doi = {10.1186/1471-2288-11-168},
}