The ability of the health system to meet the population's legitimate expectations regarding their interaction with the health system, apart from expectations for improvements in health or wealth 
WHO Definition of Responsiveness
"the ability of the health system to meet the population's legitimate expectations regarding their interaction with the health system, apart from expectations for improvements in health or wealth". 
The concept of responsiveness was developed as part of WHO's broader conceptual framework on health systems developed in 2000, which identified three focuses for health system goals: health, responsiveness and financing fairness (Link for reference to report). The framework's underlying reasoning behind including responsiveness was that as a social system, the health system, like other social systems (e.g. justice, education), was expected by its populations to meet a core goal plus, common social goals expected of all social systems, in additional to their main aim. In the case of the health system, the main aim is to produce a health in the population that is equitably distributed. However the population also expects the health system to treat people with dignity."
Additional Notes on Responsiveness
Camobreco & Barnello, 2008
Policy tie-in: "These findings suggest that lawmakers will attempt to respond to public preferences about contentious morality policies despite the imposition of an external policy constraint." 
Keyes & Benavides, 2017 
"a responsive public administration establishes the ability to increase efficiency and effectiveness while balancing the needs of it citizenry...Governments, especially local governments, have the capacity to engage its citizenry in the decision-making process and foster a reciprocal relationship between citizen and administrator to facilitate fairness in the democratic process (Denhardt & Denhardt, 2001; King & Stivers, 1998)...While efficiency and effectiveness are central tenets of public administration, public interest has continued to direct attention to overall performance as a measure of responsiveness (Vigoda, 2000)"
Tie-in to (environmental) sustainability, responsiveness refers to "bottom-up" social innovation and policy development.
- Differentiate 'response' to 'influence/capture' | Ringquist, E. J. (1994). Policy influence and policy responsiveness in state pollution control. Policy Studies Journal, 22(1), 25.
- Gismondi M, Cannon K. Beyond policy “lock-in”? The social economy and bottom-up sustainability. Canadian Review of Social Policy. 2012 Jan 1;67:58-73.
- "Exploratory work within three policymaker institutions and eight reconvened focus groups were carried out in three different European countries (France, Germany, Spain). All the groups explored active practices with regard to energy saving at household level..." | Espluga J, Konrad W, Mays C, Oltra C, Poumadere M, Prades A. How to address citizens' practices and policies on sustainability? A consultative tool for brokering policy-related knowledge between the worlds of policymaking and everyday citizens' life. Evidence & Policy: A Journal of Research, Debate and Practice. 2016 Aug 30;12(3):381-404.
 World Health Organization. The World Health Report 2000, Health Systems: Improving Performance. Geneva: WHO; 2000.
 Camobreco JF, Barnello MA. Democratic responsiveness and policy shock: The case of state abortion policy. State Politics & Policy Quarterly. 2008 Mar;8(1):48-65.
 Keyes L, Benavides A. Local government adoption of age friendly policies: An integrated model of responsiveness, multi-level governance and public entrepreneurship theories. Public Administration Quarterly. 2017 Apr 1:149-85.