The nurse call system is the lifeline for a patient in a hospital room. Nurse call systems help patients initiate calls from their room in a hospital, and the response to these calls is a crucial factor in providing timely quality care and improving patient satisfaction. Two questions arise in relation to response time. Are there differences in the response to patient calls in different hospital units? Does an IT-enabled escalation of calls to ensure care quality improve the call response efficiency and effectiveness? In this study, we explore these two research questions. We argue that differences in call response time are influenced by two operational attributes of care units: velocity and uncertainty. These attributes will determine how nursing staff view both the need and urgency associated with calls and respond to them. Internet discussion forums at allnurses.com (secondary data analysis) are used to answer the first question. The analysis validates a 2 × 2 framework, which maps four different hospital units on velocity and uncertainty dimensions. A quantitative approach is then used to address the second question by analyzing the response time differences to patient calls by different hospital units when an IT-based escalation protocol is used. Data from 1,131 patient rooms provides evidence of response time differences in different units, each with a varying degree of velocity and uncertainty. We then discuss the implications of this research for future studies on patient satisfaction using a single metric such as nurse call response time.