Case series is a type of study where a small number of people or patients are observed.  This is the weakest form of study design because it does not include a comparison (or control) group.

The Center for Health Care Strategies (CHCS) is a nonprofit health policy resource center dedicated to improving the quality and cost effectiveness of health care services for low-income populations and people with chronic illnesses and disabilities. CHCS works directly with states and federal agencies, health plans, and providers to develop innovative programs that better serve people with complex and high-cost health care needs.

The Center for Health Improvement (CHI) is a national, independent, nonprofit health policy and technical assistance organization dedicated to improving population health and encouraging healthy behaviors. Since its inception in 1995, CHI has used evidence-based research to help public, private and nonprofit organizations strengthen their capacity to improve the quality and value of health care and enhance public health at the community level.

The Chronic Care Model is a model developed by Edward Wagner and colleagues that provides a solid foundation from which health care teams can operate. The model has six dimensions: community resources and policies; health system organization of health care; patient self-management supports; delivery system redesign; decision support; and clinical information system. The ultimate goal is to have activated patients interact in a productive way with well-prepared health care teams. Three components that are particularly critical to this goal are adequate decision support, which includes systems that encourage providers to use evidence-based protocols; delivery system redesign, such as using group visits and same-day appointments; and use of clinical information systems, such as disease registries, which allow providers to exchange information and follow patients over time.

A Chronic Disease is a sickness that is long-lasting or recurrent. Examples include diabetes, asthma, heart disease, kidney disease and chronic lung disease.

A citation gives information on where to find a published article.  It tells the title and date of the magazine or journal where the article was published.  It gives the authors' names, the title of the article, and page number where the article can be found.

Clinical practice guidelines are developed through a formal process and combine the best available current scientific evidence and research with expert clinical opinion to recommend appropriate steps in the diagnosis, management and treatment of patients with various chronic diseases and other health disparities.  Clinical practice guidelines serve to operationalize standards of care.  A series of 19 Clinical Practice Guidelines has been developed by AHRQ.  Other organizations also develop clinical practice guidelines, including ASCO and NCCN.

A clinical trial is a research study where a new treatment or other health intervention is tried out on people.  Clinical trials test how well and/or how safely a new treatment works.  Some clinical trials use control groups and randomization.  See also Randomized Controlled Clinical Trial.

The Centers for Medicare and Medicaid Services is an agency under the Department of Health and Human Services that provides publicly funded health insurance programs for specific populations, including the elderly, the disabled, individuals with end-stage renal disease, low-income individuals and families, and children.  Together, Medicare and Medicaid provide health coverage for over 80 million Americans, making CMS one of the largest health care payers in the U.S. health care system.  CMS also works to improve the quality of cancer care using reimbursement incentives, reporting requirements, and demonstration programs that test new health care delivery systems, payment approaches and/or coverage of new types of services.

The percentage a patient pays for a medical service generally after a plan deductible is met and it can vary by plan.  Your insurer may pay 80 percent of the cost of an x-ray and you pay the remaining 20 percent.

Several methods of comparing interventions, including cost-effectiveness analysis (CEA), and cost utility analysis (CUA).  CEA is a method of standardizing costs and benefits of an intervention, where the cost is usually expressed in dollars.  The effect depends on the intervention being considered.  CUA describes whether an intervention is "worth is."  It describes the ration of cost to a quality adjusted life year (QALY).  QALYs include gains in prolongation and quality of life.

Federally funded research into which medical procedures and treatments are most effective.

The degree to which the investigator is confident that the true value lies in the interval stated.  In other words, the confidence interval (CI) provides an estimated range of the true population measure, given the study data, and shows the probability that the true value falls within this range.

A Consumer is an individual who uses, is affected by, or is entitled or compelled to use a health-related service.

The Consumer Assessment of Healthcare Providers and Systems (CAHPS) develops and supports the use of a comprehensive and evolving family of standardized surveys that ask consumers and patients to report on and evaluate their experiences with health care. These surveys cover topics that are important to consumers, such as the communication skills of providers and the accessibility of services. CAHPS originally stood for the Consumer Assessment of Health Plans Study, but as the products have evolved beyond health plans, the name has evolved as well to capture the full range of survey products and tools.

These plans typically pair high-deductible insurance with a health savings account or an employer-funded health reimbursement arrangement to help manage out-of-pocket costs.
These plans often give the customer a lower premium, but they must pay a high deductible before coverage starts.  For plans with health savings accounts, that deductible must be at least $1,200 for individuals and $2,400 for family coverage next year.  
The idea behind them is to give customers an incentive to shop judiciously for health care.

Consumer Engagement is the situation in which consumers take an active role in their own health care, from understanding their own conditions and available treatments, to seeking out and making decisions based on information about the performance of health care providers.

The Consumer-Purchaser Disclosure Project (CPDP) is a group of leading employer, consumer and labor organizations working toward a common goal to ensure that all Americans have access to publicly-reported health care performance information. CPDP's shared vision is that with this information, Americans will be better able to select hospitals, physicians and treatments based on nationally standardized measures for clinical quality, consumer experience, equity and efficiency.

A control or control group can be found in clinical research, such as randomized controlled trials.  In these studies, the control is a group of patients who do not get the new treatment or health intervention.  Instead they get the standard treatment for the same disease.  The researchers then compare results for the patients getting the new treatment (investigational or experimental group) to the control group's results.  Another name for the control group is the "comparison group."

A controlled clinical trial has one or more test treatments and at least one control treatment.

Coordination of Care comprises mechanisms that ensure patients and clinicians have access to, and take into consideration, all required information on a patient's conditions and treatments to ensure that the patient receives appropriate health care services.

A co-payment is a fixed amount that patients pay for medical services.  Co-payments are a part of many health insurance plans.  For example, a health insurance plan may require patients to pay $10 for each doctor visit or $10 for a particular prescription drug.  Co-payments differ from insurance premiums in that patients make co-payments at the time they receive a medical service, while premiums are the cost of health insurance and are usually paid on a monthly basis by an individual and/or an individual's employer.

Core Measures are specific clinical measures that, when viewed together, permit a robust assessment of the quality of care provided in a given focus area, such as acute myocardial infarction (AMI).

See Comparative Effectiveness.

See Comparative Effectiveness.