The Peer Assessment Rating (PAR) index

The PAR index is a fast, simple and robust way of assessing the standard of orthodontic treatment that an individual provider is achieving.

The PAR index is primarily designed to look at the results of a group of patients, rather than an individual patient, as there are always a small number of patients where the index does not fully represent the result obtained. The index is, however, generally accepted by the British Orthodontic Society as a useful tool in this area.

For its use to be accurate and reproducible, any individual providing a PAR scoring service must have first successfully passed an appropriate calibration test and have documentary evidence of this. Unless an individual is calibrated on the use of the index, the results they produce will not be valid or reproducible and should not be used to assess the standard of someone else’s treatment. Re-validation is also advisable and evidence of attending a "refresher" course would be advisable. It is the responsibility of the “user” (e.g. specialist or PCT/LHB) to ensure that the person scoring the models has been properly calibrated.

With respect to interpreting the results, a mean PAR score improvement of greater than 70% represents a very high standard of treatment. Less than 50% shows an overall poor standard of treatment and less than 30% means the patient’s malocclusion has not been improved by orthodontic intervention. It must be stressed, however, that the index is designed to look at a large group of patients rather than an individual patient’s outcome