Many other factors affect the choice of treatments. They include a lack of access to independent information, availability of medicines, cost, culture and politics. For example, even if a practitioner could be aware of all the 'scientific' data, a particular treatment option may be inappropriate in a local community if the product is not locally available, is too expensive, or its use clashes with local practice or customs. In deciding on a particular treatment, practitioners need to consider the alternative approaches available (including no treatment), and the evidence on the comparative benefit/harm balance of the alternatives, together with local customs, costs and resources.