Vast global resources are ploughed into the delivery of treatment interventions ranging from diet and lifestyle advice to complex surgery. In all cases, whatever the intervention, unless the recipient is engaged with the process and understands why the intervention has been offered and the part they play in its success, compliance will be an issue. This book aims to explore the key factors which drive compliance and the part that healthcare professionals can play in improving this, with the key underlying goal of improving public health in its broadest sense.