In order to consider the most appropriate way to provide out-of-hours general practice care, it is helpful to disentangle the characteristics of the providers of care from the different means (forms of care or settings) in which care is delivered. For example, it is possible to compare the advantages and disadvantages of home visits and telephone advice, as different means of providing out-of-hours care. It is also possible to compare the relative merits of alternative providers, such as deputising services or GP co-operatives.