The open source cityEHR system was evaluated as a toolkit for clinician-led development of an Electronic Health Record for management of patients in the Ponseti clinic of a major London hospital. As a toolkit, it was found that the ontology-driven approach of cityEHR was too complex for clinicians to use. The toolkit was refined to use more familiar spreadsheet s to represent the ontology and was then used successfully to create an effective clinical system, generated automatically from the information model.