We reduced the number of chronic conditions used, in order to simulate studies that were based on fewer chronic conditions. We used the 11 minimum chronic conditions as suggested by Diederichs et al),12 (link) the 12 most prevalent chronic conditions in our study (hypertension, hyperlipidaemia, ischaemic heart disease, type 2 diabetes, obesity, osteoarthritis, chronic back pain, asthma, depression, anxiety, gastro-oesophageal reflux disease and malignant neoplasms) as suggested by Fortin et al11 and the 24 listed chronic conditions with a tick box. We then compared these results with those generated using all diagnosed chronic conditions.
BEACH substudies have a single stage cluster design, with each GP having 30 patients clustered around them. The cluster effect was accounted for using SAS V.9.3.