Table 1 Critique of three most commonly used HRQOL models

Internal criticism

Adequacy

Addresses a defined area

· Completeness

· Complete overall conceptualization of HRQOL from biomedical and social science perspectives

· Expanded Wilson &; Cleary’s model to better explicate individual and environmental factors

· Complete overall conceptualization of health from biomedical and social science perspectives

· Gaps

· Gaps include management of therapeutic regimens and self-management

· Gaps still include management of therapeutic regimens and self-management

· Gaps include determinants of health, management of risk factors, and self-management

· Need for refinement

· Refinement for specific practice situations needed.

· Refinement for specific practice situations needed.

· Refinement for specific practice situations needed.

Clarity

· Main concepts well-defined, although individual and environmental characteristics not explained.

· Main concepts well-defined, including individual and environmental characteristics.

· Main concepts well-defined, with the exception of overlap between activities and participation.

Explicit components

· Explicit proposition that dominant relationships exist with the potential for reciprocal relationships.

· Explicit proposition that dominant relationships exist with the potential for reciprocal relationships.

· Explicit propositions exist with reciprocal relationships that can be used to map the constructs and domains.

· Concepts (components) defined

· Strength of the relationships of each component is unclear and with each additional relationship the complexity increases.

· Propositions were added with individual and environmental characteristics.

· Explicit assumption that model provides a multipurpose classification and can serve as a unified and standard language for health care workers, researchers, policy-makers, and the public.

· Explicit propositions (Relationships)

· Other relationships were implied.

· Nonmedical factors removed; described as part of individual and environmental characteristics.

· Explicit assumptions (Beliefs)

· Explicit assumption that understanding relationships among these domains will lead to the design of optimally effective clinical interventions.

· Explicit assumption that understanding relationships among these domains will lead to the design of optimally effective clinical interventions.

· Another explicit assumption is that model can be used to help plan interventions for functional goals and health, worldwide.

Consistency

Consistency

· Concepts Congruency

· Concepts consistently defined.

· Concepts consistently defined.

· Concepts consistently defined.

· Assumptions (beliefs)

· Assumptions were congruent

· Assumptions were congruent

· Assumptions were congruent

· Propositions (relationships)

· The figure depicts dominant directional relationships whereas the text mentions reciprocal and other non-depicted relationships.

· Propositions were congruent.

· Propositions were congruent.

Logical development

· Emerged based on research from biomedical and social sciences.

· Revision of Wilson &; Cleary

· Integration of medical and social models for a biopsychosocial approach.

Based on previous work Evidence supports

· Relationships depicted don’t always hold true, research evidence supports lack of relationships in some instances (e.g., biological vs. symptoms)

· Emerged based on empirical evidence and the need for further clarity.

· Evolved over time from the WHO ICIDH model in 1980 to the WHO ICF in 2001, with the WHO ICF-CY for children and adolescents added in 2007.

· Based on systematic field trials and international consultation.

Level of development

Level of abstraction (grand, middle range, or practice)

· Middle range but global

Middle range but global

Middle range but global

External criticism

Complexity

· Number of concepts

· 5 main abstract concepts (biological/physiological, symptom status, functional status, general health, quality of life)

· 5 main abstract concepts with further development of the individual and environmental factors.

· 6 main abstract concepts (body functions, body structures, activity, participation, environmental factors, and personal factors).

· Parsimony

· Parsimonious because used only 5 main concepts to explain abstract HRQOL.

· Parsimonious because used only 7 main concepts to explain abstract HRQOL.

· Parsimonious because used only 6 main concepts to explain abstract health and health-related states.

· Complexity

· Overall model is complex with multiple relationships

· Overall model is complex with multiple relationships

· Overall model is complex with multiple relationships

Discrimination

· First HRQOL model to combine biomedical with social science

· Revised Wilson and Cleary’s HRQOL model

· Belongs to a family of WHO Classifications, with the WHO ICF being specific to functioning and disability.

Unique theory of HRQOL with clear boundaries

· Unique to HRQOL

· Unique to HRQOL

· Not unique to HRQOL.

· Boundaries are purposefully not clear as two theories are combined and the relationships between concepts are additive.

· Clear boundaries and limited to HRQOL of individuals.

· Clear boundaries addressing health and health-related domains.

· Hypotheses generation may help to clarify boundaries.

· Does not cover non-health related circumstances.

Reality convergence

· Moving from cellular level to quality of life in model seems more realistic than traditional biomedical model by itself.

· Realism added with the incorporation of nonmedical factors into individual and environmental factors.

· Assumptions seem true, realistic, and consistent.

· Assumptions “real world”

· “Makes sense” for real world application.

· “Makes sense” for real world application.

· “Makes sense” for real world application.

· Theory/model “makes sense”

· Assumptions are difficult to actualize

· Assumptions more realistic

Pragmatic

Guided literature applied to real world settings:

Guided literature applied to real world settings:

Guided literature applied to real world settings:

Operationalized in real-life settings

· 3 literature reviews,

· 2 literature reviews

· 3 literature reviews

· 4 descriptive,

· 1 instrument development

· 2 instrument development

Model testing in entirety not done

Model testing in entirety not done

· 6 correlational,

· Overall, generic and situation-specific measures exist

· Overall, generic and situation-specific measures exist

· 1 randomized trial,

· Response shift is a concern for general health and quality of life components

· Response shift may also be a concern.

· 1 qualitative,

· 1 mixed methods

· 1 model revision (Ferrans) Model testing in entirety rarely done

· Overall, generic and situation-specific measures exist

· Response shift is a concern for general health and quality of life components

Scope

· breadth of theory/model

· Broad model to explain complex nature of HRQOL

· Further broadens Wilson and Cleary’s scope by expanding on individual and environmental factors

· Broad model to explain health and health-related domains for all people.

· applies across ages (lifespan), health and disease conditions, cultures, socioeconomics, and individuals/families/ communities

· Could apply to individuals of all ages, life spans, health and disease conditions, and perhaps cultures depending on their orientation to the meaning of quality of life and general health.

· Could apply to individuals of all ages, life spans, health and disease conditions, and cultures across the world.

· WHO ICF-CY specifically covers infants, children, and adolescentzs.

· May not apply to those who are unable to define their own general health or quality of life (e.g., infants, comatose), or those who have very limited functioning.

· Focus is on individuals (with or without disabilities), families, communities, and populations.

· Primarily applies to individuals, less to families and communities.

Significance

· Most widely cited HRQOL model

· Emerging citations for Revised HRQOL model

· Emerging citations for the use of the WHO ICF for hypothesis testing (mainly instrument development).

· Potential impact on practice

· Guides HRQOL assessment toward a more comprehensive approach to improving HRQOL

Potential for intervention research but limited evidence exists to date.

· Guides HRQOL assessment toward a more comprehensive approach to improving HRQOL

· As a clinical tool, can be used for needs assessments, matching treatments with conditions, and evaluating outcomes.

· Hypotheses lead to assessment or interventions

· Because of the complexity of the model and lack of testing of the full model, supporting interventions would be difficult.

· Potential for intervention research but limited evidence exists to date.

· As a research tool, can be used for measuring quality of life, outcomes, environmental factors, or other constructs.

· Potential for intervention research but limited evidence exists to date. More of a mapping and classification framework, rather than hypothesis generating.

Utility

Hypothesis generating for:

Hypothesis generating for:

Hypothesis generating for:

Hypothesis generating for clinicians, researchers, epidemiologists, policymakers

· Clinicians for a broader view of HRQOL than just biological factors and symptoms.

· Clinicians for a broader view of HRQOL than just biological factors and symptoms.

· Clinicians for needs assessments, matching treatments with conditions, vocational assessment, and rehabilitation and outcome evaluation

· Researchers to guide measurement and intervention studies:

· Expands focus of article (audience) from physicians (Wilson &; Cleary) to nurses and other health professionals (Ferrans). Model could be applied to any health care discipline.

· Researchers to guide development of measures for outcomes, quality of life, or environmental factors

· Potentially relevant to epidemiologists if using global measures across populations (e.g., SF-36).

· Researchers to guide measurement and intervention studies.

· Epidemiologists to collect and record data for populations and management information systems

· More research evidence and emphasis on environmental factors needed to convince policymakers.

· Potentially relevant to epidemiologists if using global measures across populations (e.g., SF-36).

· Policymakers to plan social security, compensation systems, and policies.

· More research evidence and emphasis on environmental factors needed to convince policymakers.

· Educators to design curriculums that emphasize awareness and social action.

· Although potential for hypothesis generation in these areas, there is currently limited evidence found in the HRQOL literature documenting these applications.