Published Online:

Problem definition: Clients and service providers alike often consider one-on-one service delivery to be ideal, assuming, perhaps unquestioningly, that devoting individualized attention best improves client outcomes. In contrast, in shared service delivery, clients are served in batches and the dynamics of group interaction could lead to increased client engagement, which could improve outcomes. However, the loss of privacy and personal connection might undermine engagement. The engagement dynamics in one-on-one and shared delivery models have not been rigorously studied. To the extent that shared delivery may result in comparable or better engagement than one-on-one delivery, service providers in a broad array of contexts may be able to create more value for clients by delivering service in batches. Methodology/results: We conducted a randomized controlled trial with 1,000 patients who were undergoing glaucoma treatment over a three-year period at a large eye hospital. Using verbatim and behavioral transcripts from more than 20,000 minutes of video recorded during our trial, we examine how shared medical appointments (SMAs), in which patients are served in batches, impact engagement. On average, a patient who experienced SMAs asked 33.3% more questions per minute and made 8.6% more nonquestion comments per minute. Because there were multiple patients in an SMA, this increase in engagement at the individual patient level resulted in patients hearing far more comments in the group setting. Patients in SMAs also exhibited higher levels of nonverbal engagement across a wide array of measures (attentiveness, positivity, head wobbling, or “thalai aattam” in Tamil: a South Indian gesture to signal agreement or understanding, eye contact, and end-of-appointment happiness), relative to patients who attended one-on-one appointments. Managerial implications: These results shed light on the potential for shared service delivery models to increase client engagement and thus enhance service performance.

Funding: This work was supported by the Wheeler Institute at London Business School (WIBAD Ramdas_Sonmez CFP19), the Institute of Entrepreneurship and Private Capital at London Business School (IIE_3432_2019), Aravind Eye Hospital, and Harvard Business School.

Supplemental Material: The online appendix is available at

INFORMS site uses cookies to store information on your computer. Some are essential to make our site work; Others help us improve the user experience. By using this site, you consent to the placement of these cookies. Please read our Privacy Statement to learn more.