The Prognostic Instrument for Melanoma (version 2.0) is a population-based tool that is based on a large amount of clinical and histopathological data from the Swedish quality registry for cutaneous melanoma (SweMR). In this updated version of the instrument, data from more than 70,000 patients with primary malignant melanoma between 1990 and 2021 have been included. Through a combination of several independent risk factors, melanoma-specific survival has been analysed for a variety of risk groups. The instrument calculates survival 1 to 10 years after diagnosis and provides an analysis at group level but can never provide an exact individual prognosis. The results are presented with 95% confidence intervals.

The prognostic instrument has been designed for use by physicians in relation to patients with primary malignant melanoma.

The analyses that form the basis of the instrument are performed on separate models for thin melanomas (≤ 1mm) and thicker melanomas (> 1mm) due to the fact that sentinel lymph node biopsy (SLNB) is generally not recommended for thin melanomas in Sweden. When choosing a thickness of 1 mm or less in the instrument, "Sentinel lymph node status" will not be included as a parameter.