The World Health Organization (WHO) has identified two paradigms of health service delivery that enable health systems to meet the health needs of populations (WHO, 2008). These include clinical and population health services. Clinical services include diagnostic, therapeutic and rehabilitative care consumed by the individual patient. Population health involves collective services. It involves health promotion and disease prevention activities targeted at groups and the population (Murray & Frenk, 2000). In this view, population health and clinical
care delivery coexist within the health system. However, in Kenya the functional interactions between these two paradigms vary. Traditionally, population health interventions are viewed from the angle of public health and are rarely integrated into the health system. An attempt to integrate public health interventions bring about tensions with the health system which is traditionally dominated by clinical interventions
According to Acheson, population health is the science and art of preventing disease and promoting health through the organized efforts of society (Acheson, 1998). Such collective efforts thus are not limited to specific services or interventions. The current trend in Kenya is to give a comprehensive functional definition of population health and advocate for organized efforts of state in realizing the meaning of population health. The goal is to have an impact on human health in the broadest sense (MOH, 2008). The collective action is through a series of functions derived from public health that cover a wide range of interventions. These include such functions as survey and analysis of population health and well-being status and its determinants (Wamai, 2004). It also involves control of risks and diseases such as infectious diseases, injuries and social problems like substance abuse. Another function is the formulation of regulations, legislation and public policies for health.
Studies show significant variations in health among individuals within the population in relation to social determinants of health (WHO, 2007; MOH, 2009).
The health of an individual is influenced by many factors such as social status, level of education and occupation. Individual lifestyle habits, especially smoking and alcohol use also affect the state of health and well-being. For example, some studies estimate that in Kenya smoking is responsible for at least 3% of all deaths in adults aged 35 to 84 (Eriksen et al, 2012). There is growing acknowledgement that lifestyle habits of individuals are largely influenced by the social and economic environments in which people live.
Understanding of the concept of health determinants has led researchers to develop population health models that attempt to comprehend the various determinants (Evans and Stoddart, 1990). Health status results from multiple determinants hence none of them is overriding. For example, in Kenya unemployment causes social isolation and poverty (IPAR, 1997). These then affect an individual's psychological health and capacity to adapt to new situations. Moreover, factors that influence the health of an individual are not necessarily the same as those influencing the health of the population. This is because health determinants act at both individual and collective levels. This notion is in agreement with Rose's observation that the causes of individual cases are not the same as the causes of overall incidence (Rose, 1985)), hence the divergent values.
Public health adopts a comprehensive approach, focusing its actions on many health determinants to improve and maintain population health (WHO, 1986). While this perspective includes clinical care delivery in determinants of health, it
is not restricted to clinical function and has allocated it limited space the result being a conflict of values in the clinical setup. Thus clinical care in Kenya has a limited positive impact on population health compared to other determinants such as lifestyle habits.
Public health interventions in Kenya health system are broad and involve prevention and promotion initiatives (Muga et al, 2005). Disease prevention thus includes risk reduction and refers to interventions whose goal is to forestall an event or particular health condition either to an individual or population. This approach targets individuals and groups that face identifiable risk factors and mainly focuses on disease.
There is no simple framework available for dealing with ethical conflicts in population health in spite of the tendency of ethical principles to infringe upon each other. Some formulators of the public health frameworks agree that the principles cannot be ordered according to priority but must be weighed in concrete circumstances. Kass and Childress et al. identify criteria for this weighing process (Kass, 2001:1776-1782; Chilress et al, 2002:170-178). They argue that the burdens of a population health program should be proportionate to accruing benefits to constituent members. They further refer to the 'harm principle', which implies that restrictions to personal freedom should be minimized and that they can only be justified if necessitated by a clear population health requirement. The framework by Childress et al. puts ethical conflicts at the
centre, rather than merely highlighting out ethical values. They advance five justificatory conditions for population health programs that infringe moral principles: effectiveness, proportionality, necessity, least infringement, and public justification.
Health promotion thus operates within group dynamics and the goal is the health and well-being of the population as a whole. Health promotion interventions not only target changes in individual characteristics but are now touching on ecological approaches that involve community and policy initiatives, hence the need for greater synergies.