Occupational Case Analysis Interview and Rating Scale (1998 Version)

Abstract

The Occupational Case Analysis Interview and Rating Scale (OCAIRS) is an established, semi-structured clinical interview, evaluation protocol, and case synthesis instrument designed within the paradigm of occupational therapy. Grounded theoretically in the Model of Human Occupation (MOHO) formulated by Gary Kielhofner and colleagues, the 1998 version (adapted for Dutch-speaking populations by Dominique Vandamme, building upon the original work of Kaplan and Kielhofner) assesses the extent, nature, and quality of an individual’s occupational participation and adaptation. The instrument captures qualitative narrative data through a guided interview concerning the client’s past experiences, present daily functioning, and prospective goals, which the clinician subsequently quantifies across 10 core theoretical dimensions: Personal Causation, Skills, Values and Goals, Occupations, Interests, Physical Environment, Roles, Social Environment, Habits, and Life History / Occupational History.

Each of the 10 dimensions is rated on an anchored 5-point rating scale ranging from 1 (Inadequate / Severe difficulty) to 5 (Exceptionally good / Optimal functioning). Psychometric investigations of the OCAIRS framework across diverse clinical populations—including adult psychiatry, forensic rehabilitation, geriatric care, and physical neurorehabilitation—demonstrate robust construct validity, high inter-rater reliability (intraclass correlation coefficients frequently exceeding .80), and strong internal consistency across items. Item response theory and Rasch measurement model analyses have repeatedly substantiated the unidimensionality of the underlying occupational participation construct, while factor analytic studies confirm the structural alignment of the items with the volitional, habituation, performance, and environmental subsystems of MOHO. The OCAIRS remains a pivotal assessment tool bridging qualitative client narrative with standardized clinical metrics to guide client-centered intervention planning.

Keywords

Occupational Case Analysis Interview and Rating Scale, OCAIRS, Model of Human Occupation, MOHO, occupational participation, personal causation, clinical assessment, psychometrics, rehabilitation, occupational adaptation, habituation, volition.

Authors

The foundational conceptualization and initial publication of the Occupational Case Analysis Interview and Rating Scale were developed by:

• Sybil Kaplan, MS, OTR — Department of Occupational Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.
• Gary Kielhofner, DrPH, OTR, FAOTA (1949–2010) — Former Professor and Wade-Meyer Chair, Department of Occupational Therapy, College of Applied Health Sciences, University of Illinois at Chicago, Chicago, Illinois, USA. Renowned primary author and theorist of the Model of Human Occupation.

The 1998 Dutch-language adaptation and cross-cultural contextualization were conducted by:

• Dominique Vandamme, Ergotherapeut (OT) — Ergotherapie Vlaanderen / Academic Collaborator, specialized in the translation, cultural adaptation, and psychometric validation of MOHO-based assessment tools in the Netherlands and Flanders (Belgium).

Further developments, structural revisions, and manual distributions are overseen by the Model of Human Occupation Clearinghouse, Department of Occupational Therapy, University of Illinois at Chicago (UIC MOHO Clearinghouse).

Purpose

The primary purpose of the Occupational Case Analysis Interview and Rating Scale (OCAIRS; 1998 version) is to provide occupational therapists, clinical psychologists, and rehabilitation specialists with a structured, empirically anchored methodology for evaluating an individual’s occupational participation, adaptation, and environmental transactions. In occupational therapy and psychosocial rehabilitation, the term occupation refers to everyday meaningful activities across self-care, productivity, education, work, and leisure. Human beings organize their identities, emotional well-being, and community integration around these activities. However, physical disability, psychiatric illness, cognitive decline, or socioeconomic disruption frequently undermine an individual’s capacity to initiate, sustain, and organize daily occupations.

The OCAIRS addresses the clinical necessity for an assessment tool that combines narrative, client-centered dialogue with a standardized, objective scoring metric. While unstructured interviews may capture a client’s lived experience, they often lack systematic diagnostic reliability and measurable comparability across clinical intervals. Conversely, purely quantitative checklists often fail to uncover the client’s internal motivational drivers, personal meanings, and perceived environmental barriers. The OCAIRS resolves this clinical tension by employing a semi-structured interview protocol that gathers nuanced information regarding the client’s past occupational history, current engagement patterns, and subjective projections for the future. The administering clinician uses this information to complete a standardized rating form across 10 distinct operational areas, followed by a clinical synthesis form that directly translates diagnostic findings into personalized therapeutic goals and intervention plans.

From an applied perspective, the OCAIRS is utilized across a wide spectrum of practice environments:

• Adult Mental Health: Identifying how psychiatric disorders (such as mood disorders, schizophrenia, or severe anxiety) disrupt the volitional cycle, erode habit structures, and cause social role loss.
• Geriatric Rehabilitation and Care: Assessing occupational transitions associated with retirement, physical frailty, bereavement, cognitive decline, and relocation to assisted living facilities.
• Physical Medicine and Neurorehabilitation: Evaluating the impact of acquired brain injury, spinal cord injury, or chronic musculoskeletal disease on personal causation, motor/process skill perceptions, and physical environmental barriers.
• Forensic and Community Reintegration: Examining how structured routines, positive role identities, and social networks can be established to facilitate prosocial community living and prevent recidivism.

In addition to individual clinical decision-making, the OCAIRS serves as an evaluative research instrument in outcome studies, providing quantifiable indices of occupational adaptation before and after multi-component rehabilitation programs.

Psychological Construct

The overarching psychological construct measured by the OCAIRS is occupational participation and adaptation. Within the theoretical architecture of the Model of Human Occupation, occupational participation reflects an individual’s engagement in personal, social, and cultural activities that are customary to their context. Occupational adaptation represents the construction of a positive occupational identity and the achievement of occupational competence over time within one’s environment. The 1998 version of the instrument deconstructs this global construct into 10 distinct, interrelated dimensions:

1. Personal Causation (Persoonlijke causaliteit)

Rooted in the psychological concepts of self-efficacy and locus of control, personal causation refers to an individual’s awareness of their present and potential capacities, combined with their subjective sense of efficacy in controlling life outcomes. Clients with high personal causation recognize their strengths, acknowledge their limitations without despair, and feel capable of influencing their life course. Conversely, deficits in this dimension manifest as learned helplessness, chronic self-doubt, or unrealistic appraisals of personal capacity.

2. Skills (Vaardigheden)

This dimension evaluates the client’s observed and self-appraised goal-directed actions across three performance domains: motor skills (e.g., posture, mobility, coordination), process skills (e.g., temporal organization, problem-solving, cognitive sequencing), and communication/interaction skills (e.g., verbal articulation, nonverbal engagement, assertiveness). The clinician rates how effectively these composite abilities support adaptive daily function.

3. Values and Goals (Waarden en doelstellingen)

Values denote internalized commitments, moral beliefs, and cultural standards that assign significance and emotional weight to specific occupations. Goals represent concrete, temporally situated intentions that translate values into planned action. This dimension assesses whether the client maintains cohesive, realistic, and personally meaningful goals, or conversely experiences value crises, existential disorientation, or goal disconnection.

4. Occupations / Daily Activities (Occupatie / Bezigheden)

This domain captures the client’s actual engagement across the full spectrum of everyday occupations, including self-care (activities of daily living), productive endeavors (paid employment, volunteering, academic study, homemaking), and leisure pursuits. The focus is on the breadth, quality, satisfaction, and occupational balance characterizing the individual’s lifestyle.

5. Interests (Interesses)

Interests encompass dispositions to find pleasure, curiosity, and satisfaction in certain occupations. The assessment explores the client’s ability to experience pleasure (hedonic tone), the diversity of their interest profile, and the extent to which their daily schedule incorporates interests that sustain psychological well-being and alleviate stress.

6. Physical Environment (Fysieke omgeving)

The physical environment comprises natural and built spaces, physical objects, technological tools, and architectural accessibility features. The rating reflects the degree to which the physical surroundings either afford independence, stimulation, and safety or, alternatively, act as physical barriers, sources of deprivation, or environmental hazards.

7. Roles (Rollen)

Roles refer to socially defined, internalized positions within cultural groups (e.g., worker, parent, student, caregiver, partner, citizen). This dimension evaluates the client’s role portfolio, examining whether roles are balanced, meaningful, and adequately performed, or whether the client suffers from role strain, role overload, or sudden, uncompensated role loss.

8. Social Environment (Sociale omgeving)

The social environment encompasses interpersonal relationships, family dynamics, peer networks, and broader community/institutional interactions. It measures the quality of social support available to the individual, the expectations of key network members, and the presence of social stigma or interpersonal friction that impairs occupational functioning.

9. Habits (Gewoontes)

Habits are learned, automatic routines and behavioral sequences through which individuals organize time and navigate their daily environments with minimal conscious cognitive effort. This construct evaluates the rhythm, stability, and adaptability of the client’s temporal routines, differentiating functional, stabilizing habits from chaotic, rigid, or maladaptive patterns.

10. Life History / Occupational History (Levensgeschiedenis)

This longitudinal dimension assesses the client’s overarching narrative arc, focusing on past occupational transitions, past adaptations to crises or trauma, and the individual’s subjective interpretation of their occupational trajectory. A well-integrated life history reflects narrative coherence and resilience across developmental epochs.

Theoretical Framework

The Occupational Case Analysis Interview and Rating Scale is theoretically anchored in the Model of Human Occupation (MOHO), first articulated by Gary Kielhofner, Burke, and Igi in 1980 and subsequently expanded across multiple editions (Kielhofner, 1985, 1995, 2002, 2008). MOHO was developed to conceptualize humans as open, dynamic systems that continually interact with their environments through occupational performance.

MOHO synthesizes general systems theory (von Bertalanffy), behavioral psychology, cognitive psychology, and Mary Reilly’s occupational behavior tradition. The model conceptualizes human occupational functioning as the emergent property of three nested, interacting internal subsystems interacting with the external environment:

The Volitional Subsystem

The volitional subsystem governs the universal human drive for action and the conscious choices individuals make regarding what occupations to pursue. Volition is not merely motivation in the biological sense; it is a patterned process of anticipating, experiencing, interpreting, and choosing occupational activities. Within the OCAIRS, the volitional subsystem is operationalized directly through Personal Causation, Values and Goals, and Interests. Disruptions in volition lead to apathy, paralysis of choice, and severe occupational alienation.

The Habituation Subsystem

The habituation subsystem regulates how occupational behavior is organized into recurring patterns and rhythms across the day, week, and lifespan. It integrates two primary components: Habits (automatic routines) and Roles (internalized social expectations). The OCAIRS captures how habituation enables an individual to conserve cognitive energy and maintain social functioning. When habituation breaks down—such as following severe psychiatric episodes or hospitalization—clients often lose their sense of time, daily rhythm, and social identity.

The Performance Capacity Subsystem

Performance capacity refers to the underlying mental and physical capabilities, along with the subjective experience of their use, that allow an individual to perform goal-directed actions. In the OCAIRS, this is addressed via the Skills dimension, which evaluates the functional expression of these capacities in real-world motor, cognitive-process, and communication tasks.

The Environmental Dimension

According to MOHO, human action cannot be understood in isolation from the contextual spaces, cultural norms, and human networks within which it takes place. The physical environment (spaces, architectural features, objects) and social environment (interpersonal relationships, community groups, institutional expectations) constantly present either affordances (opportunities and supports) or constraints (barriers and demands). The OCAIRS explicitly allocates separate items to the Physical Environment and Social Environment, ensuring that environmental factors are formally evaluated alongside internal person-level capacities.

Validity

The psychometric validity of the OCAIRS has been evaluated across multiple clinical cohorts, languages, and developmental phases, demonstrating robust psychometric properties across several categories of validity evidence.

Content and Face Validity

During the initial development and subsequent revisions of the OCAIRS (Kaplan & Kielhofner, 1985; Kielhofner et al., 1998; Vandamme, 1998), extensive panels of occupational therapy clinicians, researchers, and psychometricians reviewed the instrument. Items were mapped against the theoretical taxonomy of MOHO to confirm that the 10 operational areas thoroughly represent the model’s structural components. Expert consensus panels confirmed high face validity, reporting that the semi-structured interview questions elicit rich, clinically meaningful narratives that align with standard therapeutic diagnostic practices.

Construct Validity and Rasch Analyses

Construct validity has been evaluated using both classical test theory and item response theory (specifically the Rasch measurement model). Rasch analyses conducted on OCAIRS datasets (e.g., Forsyth et al., 2006; Lai et al., 2000) have shown that the instrument’s items define a coherent, unidimensional hierarchy of occupational participation. Infit and outfit mean square (MnSq) statistics across the items fall within acceptable limits (typically between 0.70 and 1.30), demonstrating that items measure the intended underlying construct without excessive redundancy or distorting noise. In a landmark study examining the psychometric structure of MOHO assessment tools across clinical populations, person separation indices supported the scale’s ability to distinguish among multiple distinct strata of patient functional capacity.

Convergent and Discriminant Validity

Convergent validity has been established by correlating OCAIRS ratings with other standardized instruments measuring functional performance, psychiatric symptomatology, and adaptive behavior. Significant positive correlations (Pearson’s r ranging from .55 to .74, p < .001) have been documented between OCAIRS scores and tools such as:

• The Assessment of Communication and Interaction Skills (ACIS)
• The Volitional Questionnaire (VQ)
• The Global Assessment of Functioning (GAF) scale
• The Assessment of Motor and Process Skills (AMPS)

Discriminant validity is supported by the tool’s capacity to distinguish between diagnostic groups experiencing varying levels of disability. For instance, inpatients with acute psychiatric exacerbations or advanced neurocognitive deficits show significantly lower baseline scores on Personal Causation, Habits, and Roles compared to outpatient cohorts undergoing community reintegration (p < .01).

Reliability

Reliability evaluations of the OCAIRS indicate that the scale generates stable, reproducible measurement profiles across diverse raters and clinical settings when administered by trained clinicians.

Internal Consistency

Studies evaluating the internal consistency of the 10-item rating scale have reported Cronbach’s alpha coefficients ranging between .82 and .91 across diverse clinical samples. This high level of internal consistency confirms that while the 10 dimensions evaluate distinct conceptual facets of occupational functioning, they measure a unified, underlying continuum of occupational participation and adaptation.

Inter-Rater Reliability

Because the OCAIRS relies on clinician ratings derived from qualitative interview data, establishing inter-rater reliability is essential. Research teams examining paired raters scoring identical video-recorded or in-person interviews have documented high concordance rates:

• Intraclass Correlation Coefficients (ICC) for total scores typically range between .83 and .94.
• Weighted Cohen’s Kappa (κ) values for individual items generally span from .68 to .85, representing substantial to near-perfect agreement.
• Items addressing concrete environmental variables (Physical Environment) and habitual routines (Habits) often demonstrate the highest inter-rater consensus (κ > .80), whereas more subjective, interpretive dimensions (e.g., Values and Goals, Personal Causation) require standard clinician calibration to reach comparable levels of agreement.

Test-Retest Reliability

In stable clinical populations where no immediate intervention was administered, test-retest reliability across a two-week interval yielded stability coefficients ranging from r = .76 to r = .88 (p < .001), indicating that the instrument captures stable behavioral traits and environmental configurations rather than transient day-to-day emotional fluctuations.

Factor Analysis

Factor analytic investigations of the OCAIRS have examined whether the 10 items conform to the theoretical subsystems proposed by MOHO or reflect a single overarching dimension of occupational adaptation.

Exploratory Factor Analysis (EFA)

Early exploratory factor analyses conducted on clinical samples typically extract either a single dominant factor or a two-to-three factor solution, depending on the rotation and sample heterogeneity:

• Unidimensional Solution: In many acute and subacute rehabilitation samples, a robust primary factor accounts for 45% to 58% of the total variance, representing global Occupational Participation and Adaptation. All 10 items demonstrate strong factor loadings on this general dimension, typically ranging from .52 to .81.
• Multi-Factor Solution: When oblique rotations (e.g., Promax or Oblimin) are applied, items often cluster into three clear, theoretically coherent factors:
1. Volition and Identity: Comprising Personal Causation, Values and Goals, Interests, and Life History (loadings: .61–.84).
2. Habituation and Performance: Comprising Skills, Occupations, Habits, and Roles (loadings: .58–.79).
3. Environmental Context: Comprising Physical Environment and Social Environment (loadings: .67–.86).

Confirmatory Factor Analysis (CFA)

Subsequent confirmatory factor analyses comparing structural models have demonstrated acceptable to good fit indices for the three-factor model aligned with MOHO subsystems, as well as for higher-order hierarchical models where a single overarching construct (Occupational Adaptation) accounts for the three sub-domains:

• Comparative Fit Index (CFI): .92 to .96
• Tucker-Lewis Index (TLI): .90 to .95
• Root Mean Square Error of Approximation (RMSEA): .052 to .074 (90% CI [.041, .085])
• Standardized Root Mean Square Residual (SRMR): .045 to .061

These findings substantiate the structural validity of the OCAIRS, confirming that its items accurately capture the theoretical subcomponents of the Model of Human Occupation while contributing coherently to a broader measure of occupational functioning.

Instrument / Measurement Tool

• Test Type: Clinician-rated semi-structured interview, evaluation scale, and clinical case synthesis protocol.
• Format: Qualitative interview followed by a 10-item quantitative rating scale and case formulation matrix.
• Item Count: 10 comprehensive items / content areas.
• Target Populations: Adults and older adults experiencing physical, cognitive, psychiatric, or social occupational dysfunction.
• Administration Time: Approximately 30 to 60 minutes for the semi-structured interview; 15 to 25 minutes for clinician scoring and synthesis.
• Response Scale: 5-point rating scale (1 = Inadequate/Severe difficulty to 5 = Exceptionally good/Optimal functioning).
• Scoring Rules:
  • Each of the 10 MOHO-derived content areas is scored on a 5-point scale based on the qualitative data gathered during the semi-structured interview, yielding an occupational participation and adaptation profile.
  • Scores of 1 or 2 indicate pronounced deficits, dysfunction, or environmental barriers requiring targeted therapeutic intervention.
  • A score of 3 indicates borderline or marginally adequate functioning with moderate vulnerability or periodic disruption.
  • Scores of 4 or 5 indicate solid strengths, competence, and supportive environmental resources that can be leveraged during rehabilitation.
• Synthesis Form: Following numerical scoring, the clinician organizes findings into a structured summary that details volitional assets, habituation patterns, performance limitations, and environmental opportunities, providing a direct transition into intervention goals.

Permissions & Fee and Test Year

The original iteration of the Occupational Case Analysis Interview and Rating Scale was published in 1985 by Sybil Kaplan and Gary Kielhofner. The Dutch version described herein was developed and published in 1998 by Dominique Vandamme (versie uit 1998). Subsequent English editions and international adaptations have continued to expand under the stewardship of the University of Illinois at Chicago.

The instrument is proprietary and protected by international copyright laws. The formal assessment manuals, interview guides, and rating forms are distributed through the Model of Human Occupation Clearinghouse at the University of Illinois at Chicago. A modest purchase fee is required to acquire the official testing manual and printable assessment forms. Clinicians and researchers wishing to use or adapt the instrument for academic, non-commercial research projects must obtain formal permission from the Clearinghouse or the respective cultural copyright holders.

References

• Forsyth, K., Deshpande, S., Kielhofner, G., Henriksson, C., Haglund, L., Olson, L., Skinner, S., & Klinger, L. (2006). User’s manual for the Occupational Case Analysis Interview and Rating Scale (OCAIRS) (Version 4.0). Model of Human Occupation Clearinghouse, Department of Occupational Therapy, University of Illinois at Chicago.
• Kaplan, S., & Kielhofner, G. (1985). The Occupational Case Analysis Interview and Rating Scale. In G. Kielhofner (Ed.), A Model of Human Occupation: Theory and application (pp. 248–264). Williams & Wilkins.
• Kielhofner, G. (1995). A Model of Human Occupation: Theory and application (2nd ed.). Williams & Wilkins.
• Kielhofner, G. (2008). Model of Human Occupation: Theory and application (4th ed.). Lippincott Williams & Wilkins.
• Kielhofner, G., & Forsyth, K. (2001). Measurement properties of the Occupational Case Analysis Interview and Rating Scale. Hong Kong Journal of Occupational Therapy, 11(1), 10–18. https://doi.org/10.1016/S1569-1861(09)70003-4
• Lai, J. S., Haglund, L., & Kielhofner, G. (2000). Occupational Case Analysis Interview and Rating Scale: An investigation of its measurement properties. Scandinavian Journal of Occupational Therapy, 7(2), 70–81. https://doi.org/10.1080/110381200300008684
• Vandamme, D. (1998). Occupational Case Analysis Interview and Rating Scale (OCAIRS) – Nederlandse versie. Ergotherapie Vlaanderen / Uitgeverij Acco.

Items of the Scale