k-Anonymity is a privacy model requiring that all combinations of key attributes in a database be repeated at least for k records. It has been shown that k-anonymity alone does not always ensure privacy. A number of sophistications of k-anonymity have been proposed, like p-sensitive k-anonymity, l-diversity and t-closeness. We identify some shortcomings of those models and propose a new model called (k,p,q,r)-anonymity. Also, we propose a computational procedure to achieve this new model that relies on microaggregation.