The methodology is described in full in the Data sources and extraction section of the paper entitled "An underreported relationship: a comparative study of pharmaceutical industry and patient organisation payment disclosures in the UK (2012-2016)". 

In brief, the data collection process involved downloading disclosure reports including payments to patient organisations made by a sample of 108 companies participating in the Disclosure UK initiative in 2016 (https://www.abpi.org.uk/our-ethics/disclosure-uk/). We subsequently searched for the annual accounts of patient organisations identified in drug company payment disclosure reports on the websites of the three UK charity regulators, that is the Charity Commission for England and Wales (https://www.gov.uk/government/organisations/charity-commission), the Scottish Charity Regulator (https://www.oscr.org.uk/) and the Charity Commission for Northern Ireland (https://www.charitycommissionni.org.uk/). The payment data from drug company payment disclosure reports and charity annual accounts was extracted into two separate Excel spreadsheets. 

We subsequently combined payment records form the two spreadsheets into a single excel spreadsheet comprising a series of drug company by patient organisation matrices corresponding with different types of analysis carried out as part of our research study.

In total, this online dataset comprises 17 web supplements with the results of calculations based on these matrices. The web supplements correspond with and provide additional background information for specific subsections in the Results section of the article entitled "An underreported relationship: a comparative study of pharmaceutical industry and patient organisation payment disclosures in the UK (2012-2016)".