A Description of Theoretical Models for Health Service Utilization: A Scoping Review of the Literature

Abstract

Theoretical models to explain health service utilization are numerous and there is no known literature that has synthesized existing models for health service utilization. Systematic searches were conducted in PubMed, MEDLINE, PsychINFO, Scopus, and CINAHL databases from 1960 through May 2021. Literature theorizing models/frameworks for health service utilization were included. Multiple investigators screened citations and full texts. Data extracted included: (1) citation information, (2) purpose of models, and (3) major constructs of models. The search retrieved 6639 citations. A total of 34 articles were eligible for this review. Theoretical models were categorized into 4 thematic domains based on the purpose of the model: (1) generalized health service utilization, (2) health service utilization with respect to specific sociodemographic determinants of health, (3) health service utilization specific to illness or health disciplines, and (4) preventive health services/screenings. There was an increase in models developed over time with a trend toward model development specific to sociodemographic determinants of health, illness, and/or health disciplines. This review cataloged theoretical models for health service utilization by thematic domain to enhance the identification and critical review of existing models. Findings support the notion that theoretical pluralism has been adopted in the field of health service utilization.

• What do we already know about this topic?

• Several theoretical models exist in attempt to describe health service utilization.

• How does your research contribute to the field?

• This scoping review synthesized the literature on theoretical models to explain health services utilization and demonstrates theoretical pluralism across available models.

• What are your research’s implications toward theory, practice or policy?

• This research aids future researchers and policymakers by cataloging available theoretical models to describe health service utilization that may be adopted and applied to specific contexts.

Introduction

Health service utilization has been described as the product of interactions between healthcare professionals, the generation of health services, and patients. ¹ At the most basic level, health service utilization is determined by the need and supply of health services. ² However, health service utilization is significantly more complex and multidimensional with many underlying factors potentially playing a role in the health service utilization process. ¹

The delivery of healthcare contributes toward individual, community, and population level health outcomes. ³ Therefore, research efforts to understand the health service utilization process are important to equitably deliver high-quality health services to all individuals, communities, and populations. To guide health services research, theoretical models to explain health service utilization are necessary. Use of theoretical models in empirical designs and concepts can act to substantially improve empirical design and outcomes for researchers. According to Mechanic, use of theoretical models that represent the realities of the provisions of health service utilization is essential to performing high-quality health services research. ⁴

Theoretical models to explain health service utilization are numerous and there is no known literature that has synthesized existing models for health service utilization. Therefore, the purpose of this study was to: (1) synthesize the peer-reviewed literature on theoretical models used to explain health service utilization, and (2) describe the characteristics of existing models. This study demonstrates the span of available theoretical models in this field, describes themes and major constructs of existing models, and aids the development of future research and decision making related to various contexts of health service utilization.

Methods

In accordance with recommendations by Munn et al a scoping review methodology was selected. ⁵ We aimed to clarify concepts and identify key characteristics related to concepts in order to inform future research. ⁵ This review was conducted in compliance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR). As outlined by Arskey and O’Malley, ⁶ and Levac et al, ⁷ this review was performed in 5-stages. This review was not registered prior to undertaking it as protocols do not require registration of scoping reviews.

Stage 1—Identifying the Research Question

This review addressed the following research questions:

1. What theoretical models have been used to explain health service utilization in peer-reviewed scientific literature?

2. What are the key characteristics that define existing theoretical models for health service utilization?

Stage 2—Identifying Relevant Studies

A literature search was performed on May 19, 2021 of the following databases from 1960 through May 19, 2021: PubMed, MEDLINE, PsychINFO, Scopus, and Cumulative Index of Nursing and Allied Health Literature (CINAHL). A variety of terms related to health service utilization, conceptual and theoretical models, and frameworks were combined for the database search (Table 1). Investigators were asked to identify additional studies in which they were familiar, but which were missing from the formal search. Grey literature was not included in this study. Literature identified in this search was downloaded to Zotero and duplicates were removed.

Table 1.

Database Search Example.

Patient Acceptance of Health Care/ ((healthcare or health care or patient*) adj5 (accept* or nonaccept* or non-accept* or utiliz* or nonutiliz* or non-utiliz* or seek*)).mp. Models, Theoretical/ or Concept formation/ or Models, Biopsychosocial/ or Models, Organizational/ or exp Models, Psychological/ ((theoretic* or thematic* or concept* or theory or theori*) adj3 (model* or study or studie* or framework* or frame work*)).mp. ((transtheoretic* or health belief or biopsychosocial or organizational or psychological) adj1 (model* or framework*)).mp. limit to English

Stage 3—Study Selection

Eligibility criteria

English-language literature discussing theoretical models for health service utilization were included in this review. Consistent with a prior literature review that assessed theoretical models in a specific field, this review focused on literature that had a primary objective to: (1) describe a theoretical model to explain health service utilization, or (2) describe a modification of a previously identified theoretical model used to explain health service utilization. ⁸ We narrowed our eligibility to only include papers which theorized health service utilization models/frameworks. Studies which described the application of existing theoretical models to a specific health condition or setting were ineligible for this review. Experimental, observational, and cross-sectional study designs that included the testing or development of theoretical models were ineligible for this review. Lastly, literature reviews comparing theoretical models were ineligible for this review.

Article selection

De-duplicated citations were uploaded from Zotero to Rayyan ⁹ for screening of title/abstracts. One investigator independently screened titles and abstracts for evaluation against the eligibility criteria. For quality assurance a second investigator independently screened a random 10% sample of titles and abstracts for evaluation against the eligibility criteria, with a 97.8% agreement seen between investigators. Titles and abstracts that met eligibility criteria were saved and underwent independent full text screening for eligibility. Two investigators independently screened full texts for evaluation against eligibility criteria. Disagreement on eligibility was resolved by discussion and refereed by a third investigator when necessary.

Stage 4—Charting the Data

Data items & data extraction

One investigator independently analyzed the attributes of theoretical models identified in eligible literature. With consideration from a prior review which analyzed theoretical models in a specific field, the following items were extracted: (1) information of eligible literature (citation, first author, and year of publication), (2) purposes of models, and (3) major constructs of models. ⁸

Methodological quality (risk-of-bias) assessment

The aim of this review was to catalog and describe theoretical models which have been used to conceptualize health service utilization. Therefore, methodological quality (risk-of-bias) evaluations were not necessary to answer the research questions and were not performed in this study.

Stage 5—Collating, Summarizing, and Reporting Results

Descriptive numeric summary

Characteristics of eligible literature were described in a brief numeric summary, including number of identified models and associated citation information.

Qualitative thematic narrative

A qualitative thematic narrative was organized by key thematic characteristics of theoretical models. Key characteristics for each of the individual theoretical models were recorded. Key characteristics were identified as described and depicted by the authors from each of theoretical models identified in eligible literature in this review. One investigator applied codes to the key characteristics for each theoretical model. Potential themes were identified from codes and sorted according to potential themes. Individual theoretical models were not restricted to a single theme and could be sorted into multiple themes. Themes were iteratively reviewed and refined until themes were named and defined.

Results

A comprehensive database search identified 6639 citations. No articles were identified through a hand search. A total of 1913 duplicates were removed. After removal of duplicates, 4726 citations were screened and 4607 were excluded based on title/abstract irrelevance. A full-text review of the remaining 119 citations resulted in 85 articles excluded due to: wrong outcome (n = 62), wrong study design (n = 15), unavailability of full text (n = 7), and wrong publication type (n = 1). A total of 34 articles met inclusion criteria and were eligible for this review. The study selection process is illustrated in Figure 1.

Figure 1.

PRISMA flow diagram.

From: Moher D, Liberati A, Tetzlaff J, Altman DG, The PRISMA Group (2009). Preferred Reporting Items for Systematic Reviews and Meta-Analyses: The PRISMA Statement. PLoS Med 6(7): e1000097. doi:10.1371/journal.pmed1000097.

Review of the 34 theoretical models in this review revealed 4 major thematic domains, based on the purpose of the models: (1) models to explain generalized health service utilization, (2) models to explain health service utilization in respect to consideration of specific sociodemographic determinants of health, (3) models to explain health service utilization in respect to illness or specific health disciplines, and (4) models to explain health service utilization for preventive health services/screenings.

Several theoretical models were categorized under multiple thematic domains. A total of 4 theoretical models were classified under the thematic domain to explain generalized health service utilization.^10-13 A total of 24 theoretical models were classified under the thematic domain to explain health service utilization with consideration of specific sociodemographic determinants of health.^14-37 Eighteen theoretical models were categorized under the thematic domain to explain health service utilization in respect to illness or specific health disciplines.^{15,17,18,22-27,31,34,37-43} Lastly, 2 theoretical models were categorized under the thematic domain to explain health service utilization for preventive health services/screenings.^18,25 The distribution and major constructs of the theoretical models within each of the 4 thematic domains were summarized in Tables 2 to 5.

Table 2.

Theoretical Models to Explain Generalized Health Service Utilization.

Theoretical model (Author & Year)	Specific purpose of theoretical model	Major constructs of theoretical models a
Andersen, 1995	Describe a model and revisions to a model of health services use	Environmental factors (health care system, external environment) Population characteristics (predisposing, enabling, need factors) Health behavior factors (personal health factors, health services use) Outcomes (health status, patient satisfaction)
Andersen, 2008	Describe a revision to a model of health services use	Contextual factors (predisposing, enabling, need factors) Individual characteristics (predisposing, enabling, need factors) Health behaviors (personal health practices, processes of medical care, health services use) Outcomes (health status, patient satisfaction)
Magi, et al. 1981	Present a theoretical model for comparative studies for lay and medically defined need for medical care	[Client perspective (perceived need)] Expected future course of illness Perceived illness Expected outcome of medical care Medical services which ought to be utilized Utilization of medical services Experienced outcome of medical care [Physician perspective (medically defined need)] Expected future course of disease Observed disease Expected outcome of medical care Medical services which ought to be utilized utilization of medical services Experienced outcome of medical care
Kufafka, et al. 1999	Present a cognitive model that isolates and measures specific factors contributing to patient decision making	Somatic & emotional awareness Perceived threat expectation of symptoms Self-efficacy response efficacy Pre-intervention Post-intervention Acute event Symptoms Interpretation Decision Action or observation Patient at the health care facility Symptom context Clinical status Health history Sociodemographics

^aMajor constructs of theoretical models as depicted by the authors.

Table 3.

Theoretical Models to Explain Health Service Utilization in Respect to Consideration of Specific Social Determinant(s) of Health.

Theoretical model (author & year)	Specific purpose of theoretical model	Major constructs of theoretical models a
Arnault, 2018	Describe cultural determinants of help seeking	Structural circumstances Suffering experience (social context, suffering interpretation, consequence of suffering) Perceived need Help seeking actions
Bish, et al. 2005	Describe delay in help seeking of women with breast cancer symptoms	Sociodemographic factors (age, ethnicity, socioeconomic status, access to medical care) Knowledge and symptoms appraisal Attitudes to help seeking Disclosure of symptoms Intentions to seek help Help seeking behavior
Carillo, et al. 2011	Describe health care access barriers that are associated with health care disparities	Financial barriers (underinsured/lack of insurance) Cognitive barriers (knowledge, health literacy, awareness of health resources, understanding diagnosis/treatment, communication barriers, interpreter services, cross-cultural communication skills, racial/ethnic concordance of provider) Structural barriers (availability, transportation, telephone access to providers, lack of childcare, street safety, waiting time, multiple locations for tests/specialists, continuity of care, operating hours of health care facilities) Late presentation Decreased prevention Decreased care Health Outcomes Disparities
Chrisman, 1997	Describe the health seeking process as a means to natural histories of illness in any subculture	Predominantly cultural factors & symptom definition Predominantly social factors & role shift Lay consultation referral Sociocultural integration & treatment action Adherence
Christy, et al. 2014	Explain men’s colorectal cancer screening behavior	[Antecedents] Background variables (race, family history of illness, prior care) Social support variables (family/friend recommendations for screening) Masculinity variables (risk taking, self-reliance, avoidance of femininity, heterosexual self-presentation) [Mediators] Gender role conflict Healthcare experience and health behaviors Health beliefs Affect (worry, embarrassment) [Outcome] Screening
Copeland, et al. 2007	Describe sociocultural and access concepts to mental health access/utilization in African American women	Health beliefs (values, knowledge, attitudes, perceptions, mistrust, treatment history) External environment Healthcare system (availability, accessibility, referral sources, provider skills, service location, provider-patient communication, matched race of providers, cultural competency, provider attitudes) Health behaviors (health promotion practices, social support, perceived need, severity of need) Consumer satisfaction (use of service, self-efficacy, trust) Outcome (increased use & follow up, decreased drop out)
Daley, et al. 1998	Describe filtering effect of social factors on health care utilization	[Patient] Symptom Individual filter Family filter Social network filter [Provider] Resources Managed care filter Provider filter [Health care event]
Davidson, et al. 2004	Extend the Andersen behavioral model of health services utilization to examine the effects of contextual determinants of access in safety net and other community level settings	Community characteristics (safety net population, low-income population support such as Medicaid, health care market such as physician supply and managed care, safety net support such as government support of safety net and Medicaid payment level, safety net services) Individual characteristics (predisposing, enabling, need factors) Health care access and outcomes (potential access, realized access, access outcomes)
Dracup, et al. 1995	Describe causes of delay in seeking treatment for heart attack symptoms	Sociodemographic factors Personality factors Self-concept Onset of symptoms Perceived threat Cost/benefit analysis (of specific actions) Consultation counter roles Action
Eiraldi, et al. 2006	Describe help seeking behavior/service utilization among ethnic minority children with attention deficit hyperactivity disorder (ADHD)	[Problem recognition] Disorder and Informant Profile (objective assessment and need, parental perceived need/burden, other triggers such as identification from professionals, teacher characteristics, parental characteristics) [Decisions to seek help] Predisposing characteristics (demographic characteristics, fears such as stigma, sociocultural norms and values, level of knowledge of attention deficit hyperactivity disorder, parental expectations and attitudes [Service Selection] Barriers and facilitators (community and social networks, service characteristics, societal factors, economic factors) [Service Utilization Patterns] Service promoters (quality of care, service integrity, treatment adherence) Service Categories (primary care, mental health services, school support and accommodations, informal support network, juvenile justice system)
Emmering, et al. 2018	Describe a conceptual framework with consideration of social capital in older adults in context of nursing and the health continuum	[Bonding Social Capital] Structural (exclusive networks) Cognitive (trust, loyalty, reciprocity) Norms & Sanctions (verbal disapproval, withdrawal of affection) [Bridging Social Capital] Structural (inclusive networks) Cognitive (general trust, generalized reciprocity), Norms & Sanctions (shunned for behaviors) [Linking Social Capital] Structural (hierarchical) Cognitive (thin trust, reciprocity) Norms & Sanctions (formal) Nursing [Health Continuum] Health Behaviors (smoking, alcohol/drug use, physical activity, diet) Healthcare service utilization (access, wellness screens, office visits) Hospitalization/Rehospitalization Mortality
Gonzalez, et al. 1989	Adaptation of health behavior in cancer prevention as a theoretical prediction of conditions under which Hispanics seek preventive care	Demographic characteristics (age, education, income, occupation, ethnicity, marital status, dietary practices, acculturation) Environmental barriers to utilization Social support Satisfaction with client/provider relationship English proficiency Threat reduction (benefits, barriers) Efficacy Health locus of control Value orientation Health status Knowledge about cancer Health threat Preventive health care use
Grembowski, et al. 1989	Explain the probability of beginning an episode of dental care, particularly among lower-class groups	Structure (social class, sociodemographic characteristics, insurance, environment) History (usual source of care, preventive behavior, quality of care, oral health) Cognitive (dental knowledge, dental satisfaction, salience of dental care, perceived norms) Expectations (expected rewards, expected costs) Probability of beginning episode
Holliday, et al. 2019	Describe the role of institutional betrayal as a potential barrier to utilization of military sexual trauma related healthcare	Pre-military experiences (childhood trauma, social support) Military sexual trauma related institutional betrayal Trust Safety beliefs Disclosure and use of military sexual trauma related care (particularly from Veterans Health Affairs and affiliated institutions) Military sexual trauma related individual level factors (stigma, sociodemographic, knowledge-related barriers)
Lerner, et al. 2017	Present a modified version of the Adapted Behavioral Model of health care utilization for transgender people	[Contextual characteristics] Healthcare service environment (provider lack of knowledge of transgender identity issues, previous negative experiences with health care system/providers and anticipation of these experiences, inability to pay for health care services and insurance coverage, denial of services) Enabling resources (integrated health services such as referrals to specialists, health and behavioral health services) [Individual characteristics] Predisposing characteristics (beliefs such as anticipation of discrimination, sociocultural factors such as transgender stigma, provider lack of knowledge, provider discrimination, demographics such as age, ethnicity, insurance coverage) [Behavior] Health care utilization
McCaughrin, 1984	Analyze social forces in America compelling individual health decision making in economic terms and barriers to informed decision making	Threshold or trigger mechanism that generates interest and awareness of one’s health status (related to pop culture, media) Focuses behavior on promotion/prevention changes Constraints imposed by cost coverage or information related to promotion, prevention, or screening Psychosocial and economic conditions that support negative health habits (stress, work or family related factors, general economic conditions, media) Trade-offs that need to be made to achieve optimal health Sacrifices juxtaposed to enjoyable lifestyle habits that are hazardous to health Individual beliefs about susceptibility/vulnerability to illness and disease Salience of good health to the individual, Reinforcement by family, friends, socioeconomic status, religion, occupation, lifestyle, previous experience with healthcare system, perceived efficacy of medical care Willingness to take sustained action Likelihood of health behaviors (such as smoking), Likelihood of participating in prevention and promotion activities
McIntyre, et al. 2009	Present a conceptual framework that defines access to health care as the empowerment of an individual to use health care and as a multidimensional concept based on the interaction between health care systems and individuals, households, and communities	[Root causes with multiple layers of underlying issues] Power relations Professionalization Training Scope of practice Type of staff [Factors] Range of services relative to need Expectations of attitudes of providers to patients (and vice versa) [Dimensions] Availability Affordability Acceptability Access
Mejia, et al. 2008	Describe factors considered in Hispanic oral health in the United States and relationships between these factors	Individual Environment Antecedent factors Empowerment factors Risk markers (Hispanic ancestry, age, sex, marital status) Need (pain, disease, injury, restoration failure or replacement) Predisposing factors (attitudes and beliefs toward oral health, perceived general health, routine vs problem-oriented user, prior dental care experience, usual source of care) Social constructs (oral health culture, value of dental care, esthetics, health, value of maintaining natural teeth, importance of primary vs permanent teeth) Enabling factors (socioeconomic status, citizenship status/birthplace, years in United States and acculturation, health literacy and health care resource knowledge, migrant category, sense of vulnerability, stigma, discrimination, insurance) Intention to seek care Enabling social structures (family income, number of family household members, social networks/support) Geographical (region, metropolitan statistical area size, accessibility) Health care system (provider ratios, provider language or ethnicity, provider mix, special programs) Receipt of oral health care
Mohnen, et al. 2019	Describe neighborhood characteristics influence on health care utilization	[Meso-level] Neighborhood characteristics (physical environment, social environment) [Micro-level] Mediators Need Healthcare demand Healthcare utilization [Meso-level] "Enabling” Healthcare supply close by the neighborhood
Obrist, et al. 2007	Present a framework to explore and improve access to health care in resource-poor countries, especially in Africa, linking social science and public health research with broader development approaches to poverty allocation	Policies, institutions, organizations and processes Health Care Services (health facilities, private practice, drug shops, traditional healers and others) Access Utilization & quality of care Health status Patient satisfaction Equity Illness recognition and treatment seeking initiated Livelihood assets (physical capital, social capital, natural capital, financial capital, human capital) Vulnerability context
Ornstein, et al. 2015	Conceptualize how end of life costs for patients may impact health care utilization for family caregivers	Social networks Patient Family members Predisposing factors (demographics, relationship to patient, caregiving role, care preferences) Enabling factors (insurance status, regional variation, psychological distress, time burden, financial burden, belief about healthcare system) Need factors (illness, self-reported health, stress) Diagnosis of serious illness (dementia status) End of life treatment intensity (symptoms, suffering, cost, concordance with care preferences) Health care utilization (hospitalizations, ED visits, outpatient visits, psychiatric treatments, medication)
Paasche-Orlow, et al. 2007	Describe causal pathways that could best explain well-established associations between limited health literacy and health outcomes	Race/ethnicity Education Age Occupation Employment Income Social support Culture Language Health literacy Vision Hearing Verbal ability Memory Reasoning Access and utilization of health care Patient factors (navigation skills, self-efficacy, perceived barriers) System factors (complexity, acute care orientation, tiered delivery model) [Provider-Patient Interaction] Patient factors (knowledge, beliefs, participation in decision making) Provider factors (communication skills, teaching ability, time, patient-centered care) [Self-care] Patient factors (motivation, problem solving, self-efficacy, knowledge/skills) Extrinsic factors (support technologies, mass media, health education, resources) Health Outcomes
Saint Arnault, 2009	Describe cultural determinants of help seeking	Perception and labeling Social significance Causal attributions Interpretation of meanings Social context dynamics Availability of resources Exchange rules Help seeking
Yoo, 2011	Describe a broad conceptual model of vaccination and illustrate four potential determinants of influenza vaccination	Epidemic factors (ongoing epidemic, avoidance response, past epidemic, transmission rate, morbidity rate, mortality rate) Patient factors (perceived risk, ongoing epidemic, avoidance response, mass media report, demographics, health status) Provider factors (reimbursement rate, specialty, reminder system, standing orders) System factors (vaccine supply, manufacturer, public/private distribution system)

^aMajor constructs of theoretical models as depicted by the authors.

Table 4.

Theoretical Models to Explain Health Service Utilization in Respect to Illness or Specific Health Discipline(s).

Theoretical model (author & year)	Specific purpose of theoretical model	Major constructs of theoretical models a
Bish, et al. 2005	Describe delay in help seeking of women with breast cancer symptoms	Sociodemographic factors (age, ethnicity, socioeconomic status, access to medical care) Knowledge and symptoms appraisal Attitudes to help seeking Disclosure of symptoms Intentions to seek help Help seeking behavior
Campbell, et al. 1996	Describe model for consulting primary care doctors	Environment/Genetic susceptibility Demographic factors/Socioeconomic factors Illness Need for care Family & friendship networks Self-care efficacy Illness experience Information seeking behavior Stressful life events Perceived susceptibility Perceived severity of illness Perceived benefit from care Perceived costs of care Expressed demand Access Consultation to primary care
Chrisman, 1997	Describe the health seeking process as a means to natural histories of illness in any subculture	Predominantly cultural factors & symptom definition Predominantly social factors & role shift Lay consultation referral Sociocultural integration & treatment action Adherence
Christy, et al. 2014	Explain men’s colorectal cancer screening behavior	[Antecedents] Background variables (race, family history of illness, prior care) Social support variables (family/friend recommendations for screening) Masculinity variables (risk taking, self-reliance, avoidance of femininity, heterosexual self-presentation) [Mediators] Gender role conflict Healthcare experience and health behaviors Health beliefs Affect (worry, embarrassment) [Outcome] Screening
Davis, et al. 2011	Describe use of complementary and alternative medicine	Signs/Symptoms (assumption of sick role/asymptomatic) Predisposing factors (demographics, social structure, health behaviors, media cues) Access Enablement Complementary and Alternative Medicine use (practitioner-based services, products, self-care practices/therapies) Outcomes of complementary and alternative medicine use (continuous treatment, conclusion of treatment episode)
Dracup, et al. 1995	Describe causes of delay in seeking treatment for heart attack symptoms	Sociodemographic factors Personality factors Self-concept Onset of symptoms Perceived threat Cost/benefit analysis (of specific actions) Consultation counter roles Action
Eiraldi, et al. 2006	Describe help seeking behavior/service utilization among ethnic minority children with attention deficit hyperactivity disorder (ADHD)	[Problem recognition] Disorder and Informant Profile (objective assessment and need, parental perceived need/burden, other triggers such as identification from professionals, teacher characteristics, parental characteristics) [Decisions to seek help] Predisposing characteristics (demographic characteristics, fears such as stigma, sociocultural norms and values, level of knowledge of attention deficit hyperactivity disorder, parental expectations and attitudes [Service Selection] Barriers and facilitators (community and social networks, service characteristics, societal factors, economic factors) [Service Utilization Patterns] Service promoters (quality of care, service integrity, treatment adherence) Service Categories (primary care, mental health services, school support and accommodations, informal support network, juvenile justice system)
Emmering, et al. 2018	Describe a conceptual framework with consideration of social capital in older adults in context of nursing and the health continuum	[Bonding Social Capital] Structural (exclusive networks) Cognitive (trust, loyalty, reciprocity) Norms & Sanctions (verbal disapproval, withdrawal of affection) [Bridging Social Capital] Structural (inclusive networks) Cognitive (general trust, generalized reciprocity), Norms & Sanctions (shunned for behaviors) [Linking Social Capital] Structural (hierarchical) Cognitive (thin trust, reciprocity) Norms & Sanctions (formal) Nursing [Health Continuum] Health Behaviors (smoking, alcohol/drug use, physical activity, diet) Healthcare service utilization (access, wellness screens, office visits) Hospitalization/Rehospitalization Mortality
Gonzalez, et al. 1989	Adaptation of health behavior in cancer prevention as a theoretical prediction of conditions under which Hispanics seek preventive care	Demographic characteristics (age, education, income, occupation, ethnicity, marital status, dietary practices, acculturation) Environmental barriers to utilization Social support Satisfaction with client/provider relationship English proficiency Threat reduction (benefits, barriers) Efficacy Health locus of control Value orientation Health status Knowledge about cancer Health threat Preventive health care use
Grembowski, et al. 1989	Explain the probability of beginning an episode of dental care, particularly among lower-class groups	Structure (social class, sociodemographic characteristics, insurance, environment) History (usual source of care, preventive behavior, quality of care, oral health) Cognitive (dental knowledge, dental satisfaction, salience of dental care, perceived norms) Expectations (expected rewards, expected costs) Probability of beginning episode
Holliday, et al. 2019	Describe the role of institutional betrayal as a potential barrier to utilization of military sexual trauma related healthcare	Pre-military experiences (childhood trauma, social support) Military sexual trauma related institutional betrayal Trust Safety beliefs Disclosure and use of military sexual trauma related care (particularly from Veterans Health Affairs and affiliated institutions) Military sexual trauma related individual level factors (stigma, sociodemographic, knowledge-related barriers)
Kirana, et al. 2009	Conceptualize individual’s responses to illness	Intrinsic factors Subjective wellbeing New physical experience (frequency, intensity) [Subjective response] Distress (cognitive response such as importance of health status and importance of subjective wellbeing, behavioral response such as interference with daily activities, affective response such as distress, worry, depression) Evaluation of available resources (formal resources, informal resources, subjective resources) [Objective response] Action (do nothing, self-care, visit doctor) [Outcome] Outcome satisfaction (reduction of distress)
Lauver, 1992	Conceptualize care seeking behavior for cancer symptoms	Clinical and sociodemographic factors Affect Utility (expectations and values about outcome) Norms Habits Facilitating conditions Care seeking behavior
Mejia, et al. 2008	Describe factors considered in Hispanic oral health in the United States and relationships between these factors	Individual Environment Antecedent factors Empowerment factors Risk markers (Hispanic ancestry, age, sex, marital status) Need (pain, disease, injury, restoration failure or replacement) Predisposing factors (attitudes and beliefs toward oral health, perceived general health, routine vs problem-oriented user, prior dental care experience, usual source of care) Social constructs (oral health culture, value of dental care, esthetics, health, value of maintaining natural teeth, importance of primary vs permanent teeth) Enabling factors (socioeconomic status, citizenship status/birthplace, years in United States and acculturation, health literacy and health care resource knowledge, migrant category, sense of vulnerability, stigma, discrimination, insurance) Intention to seek care Enabling social structures (family income, number of family household members, social networks/support) Geographical (region, metropolitan statistical area size, accessibility) Health care system (provider ratios, provider language or ethnicity, provider mix, special programs) Receipt of oral health care
Ornstein, et al. 2015	Conceptualize how end of life costs for patients may impact health care utilization for family caregivers	Social networks Patient Family members Predisposing factors (demographics, relationship to patient, caregiving role, care preferences) Enabling factors (insurance status, regional variation, psychological distress, time burden, financial burden, belief about healthcare system) Need factors (illness, self-reported health, stress) Diagnosis of serious illness (dementia status) End of life treatment intensity (symptoms, suffering, cost, concordance with care preferences) Health care utilization (hospitalizations, ED visits, outpatient visits, psychiatric treatments, medication)
Schreiber, et al. 2009	Describe individual mental health help seeking	Traumatization Perceived problem Wish for treatment Treatment intention Help-seeking [Influencing variables] Knowledge about traumatization Social reference Social support Cognitive availability Attitude to help-seeking Post-traumatic avoidance Disrupted interpersonal trust Feasibility Expected success Guilt and shame Victim-offender relationship Experienced structural barriers Knowledge about providers Intervention of others [Higher order variables] Sociocultural background Mental health literacy Experience with help-seeking
Williams, 2014	Propose theoretical framework for the ecological and multilevel relationships among HIV/AIDS related stigma, health service utilization, and HIV outcomes	Individual Level (perception or fear of stigma, sexual and other risk behaviors, HIV transmission, health service utilization, longevity of HIV) Community Level (stigma, normalization of attitudes and behavior about HIV such as perceive threat, approval and consensus, HIV prevalence, HIV incidence)
Yoo, 2011	Describe a broad conceptual model of vaccination and illustrate four potential determinants of influenza vaccination	Epidemic factors (ongoing epidemic, avoidance response, past epidemic, transmission rate, morbidity rate, mortality rate) Patient factors (perceived risk, ongoing epidemic, avoidance response, mass media report, demographics, health status) Provider factors (reimbursement rate, specialty, reminder system, standing orders) System factors (vaccine supply, manufacturer, public/private distribution system)

^aMajor constructs of theoretical models as depicted by the authors.

Table 5.

Theoretical Models to Explain Health Service Utilization for Preventive Health Service(s)/Screening(s).

Theoretical model (author & year)	Specific purpose of theoretical model	Major constructs of theoretical models a
Christy, et al. 2014	Explain men’s colorectal cancer screening behavior	[Antecedents] Background variables (race, family history of illness, prior care) Social support variables (family/friend recommendations for screening) Masculinity variables (risk taking, self-reliance, avoidance of femininity, heterosexual self-presentation) [Mediators] Gender role conflict Healthcare experience and health behaviors Health beliefs Affect (worry, embarrassment) [Outcome] Screening
Gonzalez, et al. 1989	Adaptation of health behavior in cancer prevention as a theoretical prediction of conditions under which Hispanics seek preventive care	Demographic characteristics (age, education, income, occupation, ethnicity, marital status, dietary practices, acculturation) Environmental barriers to utilization Social support Satisfaction with client/provider relationship English proficiency Threat reduction (benefits, barriers) Efficacy Health locus of control Value orientation Health status Knowledge about cancer Health threat Preventive health care use

^aMajor constructs of theoretical models as depicted by the authors.

There was an increasing trend of theoretical models published between 1981 and 2019 that conceptualized health service utilization in context of specific sociodemographic determinants of health, illness and/or health disciplines (Figure 2). Each of the 4 theoretical models explaining generalized health service utilization were published before the year 2010.

Figure 2.

Thematic distribution of theoretical models for health service utilization by year of publication.

*SDoH: Social Determinants of Health.

Thematic Domain 1: Models to Explain Generalized Health Service Utilization

Theoretical models under this thematic domain explained health service utilization which can be applied to a variety of contexts.^10-13 Models described by Andersen included major constructs of environmental factors (ie, health system factors), population/contextual factors (ie, sociodemographics), and individual health behavior factors and outcomes.^10,11 Magi and Allander described a theoretical model that includes consideration of both patient and physician perspectives. ¹² Kufafka, et al. presented a cognitive model that considers patient decision making contributing toward the explanation of health service utilization. ¹³ It is noteworthy that although diverse lexicon is used for core sociodemographic, health behavior, and health system factor constructs in models classified under thematic domains 2, 3, and 4, these core constructs are similar, if not derived, from early models categorized in thematic domain 1.

Thematic Domain 2: Models to Explain Health Service Utilization With Respect to Specific Sociodemographic Determinants of Health

Theoretical models in this thematic domain described health service utilization in context of specific sociodemographic determinants of health.^14-37 Common sociodemographic determinants of health that were considered in these models included (sub)cultural factors, gender groups, age groups, race/ethnicity populations, access to healthcare, health disparities, geography, low-income/low-literacy populations, socioeconomic factors, and family/caregiver groups. Arnault described cultural determinants of health seeking. ¹⁴ Carillo, et al. described a model of health care access barriers that are associated with health care disparities. ¹⁶ Many of these models included core constructs such as demographic, health behavior, and health system factors. However, most models diverged from each other with the inclusion of model constructs that are specific to the sociodemograhpic determinants of health consideration for each model.

Thematic Domain 3: Models to Explain Health Service Utilization Specific to Illness or Health Disciplines

Theoretical models categorized under thematic domain 3 explained health service utilization in context of illness or specific health disciplines.^{15,17,18,22-27,31,34,37-43} Similar to models under thematic domain 2, several of the models in this thematic domain included core constructs of sociodemographic, health behavior, and health system factors; however, most models differed from each other with the inclusion of model constructs that are specific to the illness and/or health discipline consideration.

Illness considerations included cancers, oral health, end of life considerations, mental health, heart attack, attention deficit hyperactivity disorder, and HIV/AIDS. Bish et al, proposed a theoretical model to describe the delay in help seeking of women with breast cancer. ¹⁵ Christy et al proposed a theoretical model to explain men’s colorectal cancer screening behavior. ¹⁸ Dracup et al proposed a theoretical model to describe causes of delay in seeking treatment for heart attack symptoms. ²²

Health discipline considerations included primary care, complementary and alternative medicine, mental healthcare, dental care, nursing, military sexual trauma related care, and vaccinations. Campbell and Roland described a model for consulting primary care doctors. ³⁸ Davis et al proposed a model to explain the use of complementary and alternative medicine. ³⁹

Thematic Domain 4: Models to Explain Health Service Utilization for Preventive Health Services/Screenings

Theoretical models under this thematic domain intended to explain health service utilization specific to preventive health services and health screenings.^18,25 Christy et al proposed a theoretical model to explain men’s colorectal cancer screening behavior. ¹⁸ Major constructs of this model included background (ie, demographics), social support, masculinity, and mediating (ie, health behaviors, health beliefs, healthcare experience) variables. ¹⁸ Gonzalez, et al proposed an adaptation of the health behavior in cancer prevention model to explain conditions in which Hispanics seek preventive care. ²⁵ Similarly, this model included demographic, social support, and patient-provider relationship experience variables to explain preventive health service utilization. ²⁵

Discussion and Implications

This review of the peer-reviewed literature, the most comprehensive we are aware of, identified 34 theoretical models for health service utilization. Twenty-three of the 34 models have been published since the year 2004. Theoretical models were categorized by model purpose into 4 thematic domains: (1) generalized health service utilization models, (2) models adapted for specific sociodemographic determinants of health, (3) models adapted for specific illness or health disciplines, and (4) models adapted for preventive health services and screenings. Most models were proposed in context of specific sociodemographic determinants of health, illness, and/or health discipline considerations, with an increasing trend of these types of contextually focused models. Though a wide array of terminology was used across models, many of the models in this review were comprised of core constructs related to sociodemographic, health behavior, and health system factors.

This review suggests the seminal work toward theoretical model development by Andersen has contributed to lasting core constructs (sociodemographics, health behaviors, health system factors) in existing theoretical models to explain health service utilization.^10,11 Iterations of theoretical models for health service utilization have routinely incorporated these core constructs with additional adaptations to account for contextualization of the specific model’s purpose. These additional contextual adaptations include sociodemographic determinants of health, illness, and/or health disciplines. Though not necessarily theoretical models intended to describe health service utilization, other core concepts from seminal papers on access and quality of care have also been widely incorporated into theoretical models for health service utilization.^44,45

The increasing quantity of adapted iterations of models may be influenced by the evolution toward theoretical pluralism in the social sciences and systemic action research, such as implementation science.^8,46 Theoretical pluralism has been described as a widely accepted and preferred pragmatic approach to systemic action research by allowing one to view multiple theoretical “lenses” involving differing assumptions. ⁴⁶ A pluralistic theoretical approach is argued to support actionable decision-making for multiple stakeholders, such as policy makers and health administrators. ⁸ Accordingly, a pluralistic approach to theory development is argued to be an essential skill for researchers. ⁸ It has been contended that in order to provide an easily interpretable theory which can provide explicit justification for implementation strategies, detailed attention to theory development is essential.^8,47-49

Health services research, particularly that which concentrates on implementation science to address differences in health service utilization across populations, inherently demands a pluralistic approach to the application of theoretical models. Implementation science is fundamentally an applied field that is employed in and across dynamically changing and diverse environments. ⁵⁰ Thus, the significant increase in iterations of theoretical models for health service utilization that are adapted for specific contextual factors likely goes hand in hand with the adoption of theoretical pluralism within social science and systemic action research.

Conversely, as the health services research field has adopted a pluralistic approach to theory, there could be risk of hindering meaningful theoretical iterations and reducing clarity.^8,49 Healy suggests there is an anti-theoretical nature of nuance in sociological theory development and warns against falling into “nuance traps.” ⁴⁹ Healy asserts that employing iterative nuance to theory actually inhibits the process of abstraction—which theory is contingent upon—and impedes creativity as a useful theoretical process. ⁴⁹ Not only could a nuance-driven approach to theory development potentially hinder creativity and distract from theoretical problem solving, it may foster the perpetuation of nuanced theoretical models which could attenuate conceptual clarity over time.^8,47,48 Findings from this review illustrate the potential for confusion caused by the existence of a vast quantity of models and the varying terminology representing similar constructs across models. As the collection of theoretical models for health service utilization continues to expand, it is important for researchers to critically assess existing models and develop clear and consistent language that can be used in incipient models.

Limitations

This review has notable limitations. Non-English language articles in this review were excluded which may have resulted in missing relevant theoretical models. While an extensive and robust search methodology was performed, this review did not include a search of “grey literature.” This may have resulted in relevant theoretical models being missed. We acknowledge this review did not include theoretical models that are not explicitly conceptualized as models to describe health services utilization, though can be applied to explain health service utilization. For example, the health belief model and other ecological models can be used to explain health service utilization, particularly in respect to specific sociodemographic determinants of health, illness, and health discipline considerations. In addition, this review did not include articles of experimental, observational, and cross-sectional study designs that tested the development of theoretical models. Inclusion of these models would likely have yielded a significantly greater number of theoretical models. This would likely have further strengthened our argument of the increasing dilution of clarity in this field from an expanding number of proposed models with varying terminologies.

Conclusions

This scoping review of the peer-reviewed literature cataloged and described models for health service utilization. Findings of this review were organized into thematic domains to allow for easy identification and comparison of models to be selected to guide research, policy, and decision making. Findings from this review reaffirm an evolution toward theoretical pluralism with increasing quantity of model iterations that consider specific sociodemographic determinants of health, illness, and/or health disciplines.