The required elements for the reference are:
Corporate author. (Year) Title. (guideline type and number). Place of publication: Publisher. Available at: URL [Accessed date].
Reference List
Example of the full reference at the end of your assignment:
National Institute for Health and Care Excellence. (2013) Stroke rehabilitation in adults. (NICE Clinical Guideline 236). London: NICE. Available at: https://www.nice.org.uk/guidance/ng236 [Accessed 18th March 2023].
In-text citation
Example 1 - where the author's name occurs naturally in the sentence
The National Institute for Health and Care Excellence (2013) have developed guidelines to improve rehabilitation of stroke patients.
Example 2 - where the author's name does not occur naturally in the sentence
Long-term health support should encourage stroke patients to focus on life after stroke (National Institute for Health and Care Excellence 2013).