The experiment took place from January to April 2013. During this period, each patient that arrived for a diagnostic consultation was enrolled in the study. The receptionist who greeted patients explained the variety of consultations available. There were three types of diagnostic consultation available to patients:
• Basic (50 pesos): standard wait time, diagnosis in a standard room, no amenities
• Reduced wait time (200 pesos): reduced wait time, diagnosis in a standard room, no amenities
• Premium (randomized price – 250, 300, or 350): reduced wait time, upgraded room, additional
Once the options were made known, the receptionist handed a promotion card in a closed envelope to each patient from a previously randomly ordered stack. The ticket reported the randomized price of the premium consultation cost (250, 300 or 350 pesos). The patient was told that she was able to access the premium consultation at the price assigned by the ticket, and was also told the approximate wait time. The average daily number of patients was about 80, with a maximum daily number over the experimental period of roughly 150. The average expected wait time was about 3.5 hours.
Registration at the reception desk took place in a relatively private environment, as all previous patients in line were already sitting in one of the waiting rooms and patients waited in line outside the clinic before approaching the reception desk one by one. Unsurprisingly, no patient complained that the promotional price offered to them was higher than that offered to others.
Patients paying for the premium consultation were sent directly to the premium facility across the street for their consultation after registration at the reception desk. In the premium consultation building, patients were seen in a more comfortable consultation room, but the procedure for cataract detection was exactly the same as the one performed in the regular clinic. If diagnosed with cataracts, patients were then sent to see a “counselor,” a person different from the diagnostician who gave them the diagnosis, who explained options for surgery and prices and gave the opportunity to schedule surgery at the clinic. All diagnosed patients, irrespective of type of consultation, were seen by the same counselor.
Counselors were not informed if patients paid for the premium consultation, and followed the same protocol for providing information about available surgery options to all patients.