background In medicine guidelines are considered important tools for quality improvement that might also attribute to cost control.
aims This hypothesis was tested in the research project 'Fitting Medical Care' of the Royal Dutch Medical Society.
method Description of a series of investigations into the value of guidelines for the care of depressive patients. To that purpose the treatment choices, the available knowledge, the actual treatment practice and the treatment costs for depression were explored. The data were used to construct a golden standard for fitting medical care in case of depression.
results In 66% of the cases the choice of treatment was considered fitting, in 23% it was seen as undertreatment and in 11% as overtreatment. Calculation of cost-effectiveness ratios for the various treatment options turned out to be impossible given the actual body of scientific knowledge.
conclusion Guidelines can improve the quality of medical care, but are not and may never be of use for cost control