This study evaluates the implementation of the General Practitioners guidelines 'Suspicious Skin Lesions' and investigated whether their publication and implementation has led to a reduction in the proportion of referrals of low-risk patients with actinic keratosis to secondary care, after publication of the General Practitioners guidelines and implementation activities.

In the Dutch healthcare system, patients are first examined by the general practitioner who decides whether a referral to a dermatologist is indicated. Both general practitioners and dermatologists can diagnose and treat patients with actinic keratosis. Therefore, it is necessary to distinguish which patients the general practitioner should refer to a dermatologist and which patients are suitable to be treated by the general practitioner.

This retrospective data study evaluates the proportion of low risk actinic keratosis patients in 2019 en 2018.

Inclusion Criteria:

• patients of 18 years and older
• referred to dermatologist for suspicion of actinic keratosis and diagnosed as actinic keratosis by the dermatologist
• treated at MaastrichtUMC+ or TergooiHospital

Exclusion Criteria:

• different diagnosis than actinic keratosis
• referred by a different specialist than the general practitioner
• referred with multiple problems
• referred for a second opinion
• if the patients was treated as different diagnosis than actinic keratosis by general practitioner

Data from patients are collected retrospectively using the Electronic health records. Patients were selected based on the diagnosis-treatment-combination (DTC) 17 (premalignant lesion) and DTC 14 (cutaneous malignancy) that was registered from January 2018 to December 2019 by the dermatologist.