The Swede score: evaluation of a scoring system designed to improve the predictive value of colposcopy

It has been suggested that the accuracy of colposcopy is less reliable than once presumed. The Reid colposcopic index is the most well-known scoring system designed to standardize colposcopic assessment and assist in the prediction of histological diagnosis. Strander et al. have devised a new scoring system, the Swede score, which includes lesion size as a variable. This evaluation aimed to validate the Swede score within a London teaching hospital colposcopy unit.

An evaluation was carried out of women undergoing colposcopy at the Royal Free Hospital, London, UK. For 4 months, 200 women attending diagnostic colposcopy clinics or undergoing inpatient treatment of cervical intraepithelial neoplasia (CIN) were included. Participating colposcopists comprised both trained and trainee colposcopists. Swede scores were calculated at the time of colposcopy and recorded; they were compared with the final histological diagnosis after either directed or excisional cervical biopsy. Because this was an evaluation and not a research study, the Swede score was not used to influence the patient management in anyway.

Swede scores of 8 or more had a sensitivity, specificity, and positive and negative predictive values of 38%, 95%, 83%, and 70%, respectively, for lesions where the final diagnosis was CIN 2 or higher. Using the same cutoff score of 8 or higher, the first 100 examinations had similar results compared with the second set, showing that no major learning curve existed when using the Swede score.

Because the specificity when scoring 8 or higher was 95%, it is possible that higher scores within this system might be used to more accurately predict CIN 2 or higher. There was no obvious learning curve, and trainees showed comparable results compared with their trained colleagues.