HCFA
Healthcare Financing Administration. The body responsible for overseeing managed healthcare delivery in the US.

Health Economics
Economics in terms of supply and demand related to the analysis and management of disease and health. Generally concerned with equating resource utilization against health or disease outcomes.

Health Outcomes
Any outcome resulting from a treatment intervention. e.g. of efficacy, safety, quality of life, economic impact.

Health Profile
A set of scores derived from the administration of a health status instrument.

Health Related Quality of Life (HRQoL)
HRQoL is QoL without the non-health components (such as education, employment, financial, housing, nutrition) and can be defined as those aspects of human activity beyond mere survival which are affected by the provision or withholding of healthcare.

• Health State or Health Status - a description of HRQoL at a point in time.
• Health Profile vs Health Index
• Health Profile is presented in a disaggregated form and captures info simultaneously across several domains.
• Health Index is aggregated and presented as a single value of health state and captures info from several domains.

Health Status
The state of physical, psychological and mental well-being and not just the absence of disease or infirmity.

Health Status Index
Aggregation of scores of two or more domains of health-related quality of life into a single number representing the health status of individuals or populations.

Health Status Instrument
Instruments include questionnaires, interviews, or a simple checklist. Contains a single or set of item-questions intended to appraise the health status of individuals or populations.

Objective Functioning vs Subjective Wellbeing

• Objective Functioning - Measuring someone's ability to perform common tasks or activities.
• Subjective Wellbeing - Asking patients to rate the effects of health status on personal wellbeing.

Dimensions vs Domains

• Dimensions are theoretical/conceptual aspects of QoL affected by condition.
• Domains are the aspects measured through instruments (e.g. dexterity)

Items vs Levels

• Items are broken down (from domains) into the most basic components (e.g. "Can you easily tie a pair of shoes?").
• Levels comprise the response choice (response continuum) for each item (question) within a domain

Disease Specific or Generic Instrument

• Disease Specific Instrument (also termed or Single Domain Instrument) - A health status instrument that explores only one aspect of health, e.g. mental function or pain.
• Generic Instrument - Ensures broader QoL effects are captured.

Valuations vs Utilities

• Valuation - Choice-less (e.g. Profile or Index)
• Utility - Choice based (i.e. involve a trade-off such as preference, sacrifice, opportunity cost) so requires the respondent to explicitly trade health against something else that they value

Risk vs Certainty
Utility Trade Offs can be based either on:

• Risk - as in the Standard Gamble (e.g. probability of survival)
• Certainty - as in the time trade off (TTO) (e.g. life expectancy)

Validity vs Reliability vs Responsiveness

• Validity
• Content validity - relates to the range of attributes that make up the concept measured.
• Construct validity - the magnitude and direction of associations between observed scores and other theoretically related measures whether or not the instrument measures what is purports to measure.
  (a) Convergent Construct Validity: confirms that there are positive relationships between related measures (e.g. level of back pain and physical functioning domain).
  (b) Divergent Construct Validity: confirms a lack of agreement between clearly unrelated measures (e.g. a depression scale and a measure of lung function).
  (c) Longitudinal Construct Validity: change in instrument scores over time compared with changes seen in other measures (an ongoing process).
• Clinical Validity - ability to discriminate between patients with different degrees of illness severity.- Criterion Validity - relationship with other 'gold-standard' measures.
• Reliability
  The ability to produce consistent results.
• Internal Consistency: examines the relationship between individual constituent items that make up the scale (the degree of agreement between items addressing equivalent concepts).
• Inter Rater Reliability: important for interviewer-administered instruments.
• Test Retest Reproducibility: tested in same patient(s) under same conditions usually separated by at least 2 weeks; usually expressed as the intra-class correlation coefficient which yields a score between 0 and 1 (perfect reliability).
• Responsiveness
  The ability of an instrument to measure change over time - sensitivity.

Health Year Equivalents (HYE)
A measure of health-related quality of life based on individual preferences for both the duration of life and the associated health states.

Historical Data
Data (often from sales audits) showing values over recent history. Often used in sales projections, these data frequently come from IMS.

HMO
Health Maintenance Organization. A managed care system in which enrollees are offered pre-paid comprehensive healthcare coverage in contractual agreement with specified individual or group of physicians. (see also MCO (Managed Care Organizations))

Human Capital Method
A way of valuing health benefits based on the amount of goods and services that can be produced by an individual's investment of knowledge and health status.

Hypothesis
Any suggestion, whether or not based on evidence, or an assumption made as a basis for reasoning.

• Null Hypothesis, denoted H₀, in statistical hypothesis testing is the hypothesis which assumes no difference.
• Alternative Hypothesis, denoted H₁, is a statement reflecting our hypothesis of the nature and amount of change of difference.