Steady stateIn systems theory, a system or a process is in a steady state if the variables (called state variables) which define the behavior of the system or the process are unchanging in time. In continuous time, this means that for those properties p of the system, the partial derivative with respect to time is zero and remains so: In discrete time, it means that the first difference of each property is zero and remains so: The concept of a steady state has relevance in many fields, in particular thermodynamics, economics, and engineering.
Patient-reported outcomeA patient-reported outcome (PRO) is a health outcome directly reported by the patient who experienced it. It stands in contrast to an outcome reported by someone else, such as a physician-reported outcome, a nurse-reported outcome, and so on. PRO methods, such as questionnaires, are used in clinical trials or other clinical settings, to help better understand a treatment's efficacy or effectiveness. The use of digitized PROs, or electronic patient-reported outcomes (ePROs), is on the rise in today's health research setting.
Social exchange theorySocial exchange theory is a sociological and psychological theory that studies the social behavior in the interaction of two parties that implement a cost-benefit analysis to determine risks and benefits. The theory also involves economic relationships—the cost-benefit analysis occurs when each party has goods that the other parties value. Social exchange theory suggests that these calculations occur in romantic relationships, friendships, professional relationships, and ephemeral relationships as simple as exchanging words with a customer at the cash register.
Auditor's reportAn auditor's report is a formal opinion, or disclaimer thereof, issued by either an internal auditor or an independent external auditor as a result of an internal or external audit, as an assurance service in order for the user to make decisions based on the results of the audit. Auditor's reports are considered essential tools when reporting financial information to users, particularly in business. Many third-party users prefer, or even require financial information to be certified by an independent external auditor.
