Consultants are doctors who have undergone higher specialty training and work primarily in the delivery of expert clinical care. Their central duty is to carry out the investigations and procedures necessary to establish a diagnosis, and then to give advice and provide treatment or referral where appropriate. Their workload commonly involves managing the more complex type of cases (in terms of diagnosis and management decisions). Additionally, they may be involved in other areas such as managerial decisions, teaching/training, research and developing local services.