Fielding incognito standardised patients as 'known' patients in a controlled trial in general practice

Incognito standardised patients (SPs) have only been used to represent new patients so far. The few trials with incognito SPs provide little detail on the method used for fielding them.

To establish the feasibility of introducing SPs as 'known' patients (i.e. patients who have previously visited the practice) into practices, to indicate the required practice preparations, and to describe the various aspects of using SPs in a pretest/post-test design.

We used incognito SPs as known patients in a controlled trial to assess the practice behaviour of 49 trainees. The SPs received a 2-day training in role playing and completing checklists. We compiled comprehensive practice information folders of each practice to be visited. Real personal data and faked medical data of SPs were inserted in the filing system of each practice to be visited. Apart from SP roles with slightly different reasons-for-encounter and different SPs, the same training protocol, checklists and practice information folders were used in the post-test.

The SPs carried out 287 visits in 50 practices. All practices prepared the patient records for the SP visits in a fairly authentic practice style. Trainees detected the SP in 74 visits. The main reasons for detection were imperfections in patient records and aspects of SP roles or role playing.

Fielding incognito SP visits as known patients was feasible but labour-intensive. Preparing the SP patient records and familiarising SPs with the interior of practices represented new elements in the use of SPs. The pretest/post-test format made their use more efficient instead of complicating it.