1. A method for detecting fraud in health care transactions, each transaction including at least one service provided to a client by a provider on a date, the method comprising: receiving a transaction record; for each service in the transaction record: determining a time interval between the date the service was provided to the client, and a date the same service was previously provided to the client; determining a likelihood for the service to be repeated given the time interval; and responsive to the likelihood exceeding a first threshold, indicating that the transaction is potentially fraudulent.