Patients in the control group were asked to participate in a patient satisfaction study. They were asked to fill in a questionnaire with respect to patient satisfaction.

Patients in the intervention group were told that the practice was participating in a patient satisfaction study, and they were given an envelope with information about the 'doorknob phenomenon' and a request card. The envelope for the control group only consisted of information about a patient satisfaction study, without any information on the 'doorknob phenomenon', and without a request card. Both groups received the same letter with patient information about the study.

Patients in the intervention group could write down their request for help on a request card (with a maximum of 2 questions).

The primary endpoint is the 'Professional Care' (PC) scale of the 'Consultation Satisfaction Questionnaire' (CSQ). In a previous study the score on the PC were 88.2 en 80.9 in the intervention and control groups, respectively. The standard deviations were 11.8 en 16.1. For our sample size calculation we used an expected standard deviation of 15. The sample size required to detect a difference of 7 on the PC scale between the intervention and control group, with a power of 90%, and alpha of 5% (two-tailed), and a standard deviation of 15, was 196 patients. We rounded this number off to 200.

On a scale of 0-10 patients could fill in the Visual Analog Scale with regard to the patient satisfaction during the consultation