Discussion

This study reports the effect of using a method for standardising nasal surgery coding on the accuracy of data used for remuneration and benchmarking of clinical activity. ⁹ Use of the multidisciplinary coded dataset standard (‘MCDS’) document in conjunction with a clinician–auditor multidisciplinary audit significantly improved the capture of key clinical variables into codes, enabling the administrative dataset to be used as a more clinically-aligned data source. The multidisciplinary coded dataset standard process resulted in a significant reduction in the use of the ‘unspecified’ and ‘other specified’ diagnostic codes and enabled more precise codes such as deviated nasal septum (J342), inferior turbinate hypertrophy (J343) and acquired nasal deformity (M950) to be assigned. It is important to realise that the use of less specific diagnostic codes does not necessarily denote an omission or coding error, but rather that when there is more than one way of coding an activity, use of the minimum coded dataset standard allows a clinically-guided abstraction and coding path to be taken (Figure 1). This results in more clinically relevant and accurate large datasets, which allow a more precise outcome assessment along with health policies and planning.

Only two changes (1 per cent) to the coding of septoplasty procedures were indicated, but inferior turbinate surgery was under-coded, particularly when involving an outfracture that was described without detail or inclusion in procedure heading (e.g. inferior turbinate outfracture). Likewise, in a few cases, complex septorhinoplasty was obscured by imprecise description and the use of abbreviations to denote graft placement. Two important prognostic variables, smoking and revision surgery, were significantly under-coded. For example, revision surgery was not described in the surgical record but was identified from the general practitioner's letter or by reference to previous correspondence or surgical notes in the patient's notes. Likewise, smoking was not documented in the surgical record but was identified from either the general practitioner's letter or the anaesthesia record. Failure to document pertinent morbidities in patients undergoing short-stay surgery is a common problem.

Improved coding of nasal surgery activity did not lead to significant Health Resource Grouping drift and income variance, but it did lead to significant changes in the assignment of primary and secondary diagnoses and, to a lesser extent, procedures. These findings make the dataset a better tool for benchmarking and the data it contains more clinically useful.

It is therefore proposed that the coded dataset should be constructed according to certain conventions, which are embodied in the multidisciplinary coded dataset standard document. The commonest primary diagnoses were deviated nasal septum (J342), inferior turbinate hypertrophy (J343) and acquired nasal deformity (M950). It is proposed that the indication for surgery, for example whether to treat nasal obstruction (J342 or J343) or nasal deformity (M950), should be identified through assigning it to the primary diagnosis. Other diagnoses such as rhinitis can be coded in the secondary position. Most procedure codes are readily identifiable, but the use of grafts or implants in septorhinoplasty should be clearly documented. A further consideration is septorhinoplasty vs septoplasty plus rhinoplasty (Figure 2). For rhinoplasty performed to aid access to the septum to correct a complex deviation or place functional implants, the septorhinoplasty code would be most appropriate. However, for rhinoplasty performed to correct a separate nasal deformity (such as endonasal dorsum reduction and concomitant septoplasty), it may be more precise to assign separate codes for each of the septoplasty and rhinoplasty components. This would distinguish truly functional septorhinoplasty from rhinoplasty appended to septoplasty to treat a separate condition. The post-traumatic nature of nasal surgery can and should be further clarified through using specific secondary diagnoses that denote the sequelae of events (the most common are shown in Figure 2).

There are three possibilities for implementation. Firstly, the multidisciplinary coded dataset standard can be completed by the clinician as an adjunct to the operation notes. Secondly, it should be provided to clinical coding teams (along with training and discussion) and form part of a coding department's policies and procedures documents to ensure that its continued use is not affected by clinical coder rotations among different specialties. It is also possible to audit the accuracy of data coding (as in the present study), but this study has shown that such an audit would not be cost–effective.

A drawback of this study is the inherent limitation of the administrative vocabulary to capture the most subtle nuances of treatment. It can currently capture almost all septal and turbinate procedures and can differentiate between septorhinoplasty with and without the use of grafts and implants. However, although there is a specific code for the use of cartilage to reconstruct the alar cartilage (E027), the coded language cannot currently distinguish between other types of septorhinoplasty grafts. This problem may be resolved as the coding language is constantly evolving to create new codes denoting new diagnoses and procedures.