Clinical practice guidelines aim to help with decision making. However, their quality differs. Guidelines of low quality are a waste of resources and can cause patient harm. We compared the quality of the Norwegian, Danish, and Swedish guidelines on papillary thyroid cancer with those of the American Thyroid Association (ATA).

Three pairs of appraisers independently rated the guidelines using the AGREE II-instrument, a validated tool for assessing guideline quality. Further, recommendations on extent of surgery in low-risk PTC; prophylactic lymph node dissection; thyroxin suppression; radioiodine treatment; watchful waiting and length of follow-up after treatment, and the evidence cited to support the recommendations, were compared across the four guidelines.

Overall, the ATA had the highest quality, with a score of over 70 % in four domains, and the highest score in five of six domains. The Danish and Swedish guidelines reached a score of over 70 % in only one domain each, and the Norwegian in no domain. The overall score was 83 % for the ATA, 50 % for the Danish, 44 % for the Swedish and 28 % for the Norwegian guidelines. Recommendations varied widely. The ATA had the highest number of references supporting the recommendations.

The quality of clinical practice guidelines and recommendations on treatment for PTC differed between the Scandinavian countries and the ATA, with the ATA having the highest quality. International co-operation in producing guidelines seems warranted.