Population Health – the importance of taking a Public Health approach

Kathy Schneider, PhD and Miriam Isola, DrPH CPHIMS

The Expanding Interest in Population Health

The healthcare industry is experiencing a growing realization and acceptance of the importance of patient-centered care with a focus on health and wellness.  This movement is described as a shift toward population health.  Along with promoting access to medical care, one of the major thrusts of the Affordable Care Act (ACA) is to transition from an illness-based medical system that treats sick people, to one with a primary focus of keeping people healthy. 

A plethora of evidence exists that a focus on prevention can result in health system efficiencies thereby improving quality, patient experience, and managing costs.  It is typically less expensive to prevent health problems than to treat them.  For example preventing smoking is less costly than treating lung cancer or heart disease; immunizations are much more cost-effective than treating polio or pertussis.  Screening and early detection efforts with appropriate management can reduce the burden of illness and be very cost-effective (e.g., detecting and controlling high blood pressure versus treating stroke; diabetes education and care management as early as impaired glucose levels are detected[1] compared to treating diabetes-related complications).

Public Health has Always Focused on Populations

The field of public health has always had a focus on populations and can inform our work as the industry shifts to the new paradigm of population health management.   Public health was conceived centuries ago precisely to focus on population health, which is marked by a concern for improving the health of entire populations.  “Public health is the science of protecting and improving the health of families and communities through promotion of healthy lifestyles, research for disease and injury prevention and detection and control of infectious diseases.”[2]  An Institute of Medicine report from 1988 stated that public health is “…an organized community effort to address the public interest in health by applying scientific and technical knowledge to prevent disease and promote health.”[3]

Data for Surveillance and Risk Segmentation

The first step toward a population health approach is to understand the health of the population[8].  The field of public health uses an epidemiologic perspective for data discovery, and engages in systematic surveillance activities.  The key objectives are:

  • To understand the distribution of disease, and to detect a change in trends and patterns of disease;

  • To identify patterns of care that are inefficient in improving the health, and to detect changes in health care practices; and

  • Ultimately, to prevent and control disease in the community.  The focus is on identifying where action is needed.

We have witnessed the emergence of “big data” solutions to address the vast amounts of clinical data obtained by medical practitioners.  However, a broader set of information is needed to understand the health of the population.   A prerequisite for a successful population health-focused data analysis is to inventory available data sources and determine which data to include.   Typically a combination of medical claims, EMR, and other external public and community data sources are desirable.  Since health behaviors, physical environment and socio-economic factors contribute 80% to overall health, EMR data is necessary but not sufficient to accurately describe the health of the population.

Systematic surveillance of the population is an essential foundational step to understand and improving the health of the population; however, it is only the first step.  Data alone will not solve our problems – they tell us where to focus our activities and resources.  Next steps involve a risk segmentation of the population (e.g., identifying groups at high, medium and low risk for elevated medical care use). It is sometimes helpful to imagine a pyramid, with low risk at the bottom and high risk at the top.  By classifying the risk levels (or needs) of the population, the objective is to tailor intervention strategies to meet particular population needs, leading to more effective health care.

Benefits of the Public Health Approach

There are some significant benefits to using a public health approach.

  1. Public health is experienced in data discovery and surveillance

    A key public health function is to understand the epidemiology of health and disease.  Epidemiology is the study of the determinants and distribution of health-related states in the population and the application of this information to control of health problems.   An epidemiologic approach analyzes data for the entire population and uses this information to drive action. 

  2. Public health is accustomed to leveraging community resources and collaborating for change

    A public health approach includes addressing the needs of communities outside of hospital or clinic walls.  Promoting the health of populations forces us to address the social determinants of health and requires collaborations with community and public health agencies outside the medical setting.  Community health needs assessments can provide the impetus for hospitals to collaborate with community partners to work together to monitor important social determinants of health[14],

  3. Public health approaches focus on effectively targeting interventions

Targeted interventions are an effective use of resources since they match needs with services.  As patient health goals become more integrated into care plans, targeting also enables organizations to examine needs, add patient goals to the equation and then allocate resources appropriately.  Healthy populations without any chronic conditions may require different interventions to remain healthy if they are older adults rather than children; although both age groups need periodic primary care visits, immunizations and blood pressure screening, older adults should receive cancer screenings and routine laboratory work to monitor glucose and lipid levels, for example.  Furthermore, geographic and social circumstances can adversely affect health; people living in unsafe neighborhoods may lack options for healthy outdoor exercise, which increases risk of obesity and cardiovascular disease.   A combination of community and clinical approaches may have a synergistic effect for managing chronic diseases and promoting wellness.

4.  Public health approaches consider cost and efficient use of resources

An essential question for any health care delivery system is which particular resources are needed in each community.  Having an optimal mixture of primary care, specialist care, urgent care, and tertiary care – as well as social services, can effectively and efficiently serve the population.  Since the distribution of health and illness across communities is not identical – the distribution of resources across communities should not be uniform.

EMR and claims data can be used to identify trends in use, outliers, and to perform hotspotting.  By identifying people who were not efficiently served (using indicators such as over use of ED, polypharmacy, people without a primary care visit), we can better target health care resources. 

Whereas clinical medicine is driven to produce the best outcomes possible for individual patients, public health considers costs as part of the equation in determining the overall value of services.  In keeping with the Triple Aim goal for a less costly health care system, public health strives for an effective distribution of health care resources, and seeks to identify areas that may be operating inefficiently. Ultimately, the hope is that better population health will improve health care efficiencies and reduce the growth in health care expenditures. 

5.  Public health has always valued the patient experience

Public health recognizes that tests, treatments and interventions must be affordable, acceptable to people, and reasonably convenient.  There has been recent effort toward more patient-centered medical care. Gradually the healthcare industry is refining its understanding of what patient-centered really means and are working to gain acceptance of this new paradigm that enables patients to be meaningfully involved in their well-being and treatment decisions.  To make progress toward this ideal it is essential to move toward improved communication with patients, health education, and health literacy. Public health has always promoted health education, and public health research has shown that meaningful patient engagement does reduce disparities in health and lead to more positive health behaviors and improved disease self-management[1]. Thus patient engagement is essential to successful population health management

Recommendations for the path ahead

The health of the US population will benefit considerably from policy changes that have broadened the focus from a traditional medical model to a population health model.  Working toward improved population health requires us to go beyond caring for patients in a clinical setting; populations include non-patients and health occurs outside of medical facilities.  We must go beyond implementing IT systems and simply running analytics - to embrace a paradigm shift that is broader and more community oriented and patient-centered.  To do this, organizations will need to develop multi-disciplinary teams that include experts with public health experience.

The next step is for organizations to complete surveillance/data discovery and risk segmentation for their population.  Then the population health teams will be prepared to tailor the intervention strategies based on high quality and actionable data –appropriately stratified to enable identification of the particular needs of groups of people; this insight is a prerequisite for successfully identifying appropriate change strategies and interventions. 

Optimizing health requires different activities and interventions based on where a person falls on the risk spectrum and their particular health and social characteristics. Some new organizational structures such as accountable care organizations (ACOs) are well-positioned to help address the challenges of blending traditional medical care with public health, to truly become focused on population health.

For effective population health management, we need targeted interventions that are designed to shift the focus from the medical model to the population and patient.  Ultimately, adopting a public health approach will provide a number of benefits and will be a useful framework to meet the goal of improved population health.

[1] CDC. The Power of Prevention. Chronic disease…the public health challenge of the 21st century. 2009

[2] CDC Foundation website. http://www.cdcfoundation.org/content/what-public-health. Accessed 9/3/2015.

[3] Institute of Medicine. “The Future of Public Health.” The National Academies Press, Washington DC. 1988, p.7.

[8]CDC, Principles of Epidemiology. 1998 (p.293)