Early mortality after dental operations
BMJ 1994; 309 doi: https://doi.org/10.1136/bmj.309.6964.1302 (Published 12 November 1994) Cite this as: BMJ 1994;309:1302
- P G G Hardee
What constitutes a dental operation?
EDITOR, - Valerie Seagroatt and Michael Goldacre propose that an almost doubled standardised mortality ratio during the year after dental operations may be explained by the fact that they studied patients receiving inpatient rather than outpatient treatment, who by definition would have a greater risk of postoperative complications.1 The explanation may, however, be far simpler and may lie in the authors' ambiguous use of the term “dental operations.” If the term means, as most people would understand it without further explanation, dentoalveolar surgery then their results are surprising. If, however, the term refers to the full range of dental, oral, and maxillofacial surgery then such a high mortality ratio could be more easily explained: an appreciable proportion of patients admitted for oral and maxillofacial surgery will be suffering from oral, perioral, and salivary gland malignancy, which in itself carries a considerable risk of death.
It is unfortunate that Seagroatt and Goldacre do not give examples of specific dental operations, as they do with other operations, given that without further clarification their statistics are alarming - perhaps unnecessarily.
References
- 1.↵
Authors' reply
- V Seagroatt,
- M Goldacre
EDITOR, - The dental operations were those recorded as codes 251 and 252 - “simple dental extraction” and “surgical extraction of tooth” - in the third revision of the Office of Population Censuses and Surveys' classification of surgical operations (as we specified in table I in our paper).1 As we also specified, we excluded patients for whom a diagnosis of cancer had been recorded at admission. We therefore think that our results are unlikely to have been influenced by an appreciable proportion of patients having been admitted for oral and maxillofacial conditions that themselves carry a considerable risk of death.
Our aim was to quantify and attempt to interpret any short term mortality after operation by identifying, in particular, whether operations were followed by clustering of deaths shortly afterwards. We did not find a significant short term clustering of deaths after the dental operations. We found that the standardised mortality ratio for this group of patients was generally higher than the population average throughout the year.
We doubt that this is attributable in any way to the operations. We think that it is much more likely to be an effect of selection - that is, that the population that underwent dental operations was (in aggregate) slightly less healthy than the general population. One possibility, as we speculated, is that this may reflect the kind of patients who undergo these operations on an inpatient rather than an ambulatory basis. Another is that, more generally, some patients who require dental operations may be less healthy than average. If our explanation is correct - that the increased standardised mortality ratio thoughout the post operative year in this group of patients is attributable to the characteristics of the patients rather than to the operations they undergo - the findings are not alarming in respect of the risk of dental surgery.
References
- 1.↵