Evaluation of health care workers' accuracy in recognising oral cancer and pre-cancer.

The aim of the study was to evaluate dental health care workers' ability to recognise oral cancer and pre-cancer from colour photographic slides. A set of 80 slides was prepared, 40 were negative (normal mucosa or lesions with no malignant potential) and 40 were positive (cancer or potentially malignant lesions). The slides were arranged in random order and projected in a standard format. The performance was evaluated in terms of mean sensitivity, specificity, mean correct score and likelihood ratio. There were no significant differences between the three groups of dentists (consultants, juniors hospital dentists and general dentists), all performed better than the auxiliaries. The chances of a consultant making a correct decision were 5.5 times better than for an auxiliary and 2.7 times better than for a junior hospital dentist. The slide show enables a comparison of health care workers to be made and may be useful for the evaluation, training and calibration of examiners for an oral cancer screening programme.