Care Dependency Scale

1. Abstract

The Care Dependency Scale (CDS; Dutch: ZorgAfhankelijkheidsschaal) is a prominent, psychometrically validated observational assessment tool designed to evaluate the degree of care dependency in institutionalized patients, predominantly within gerontological, psychogeriatric, rehabilitation, and intellectual disability settings. Developed in the Netherlands by Ate Dijkstra, Gerrit Buist, and Theo Dassen in 1996, the instrument operationalizes care dependency across physiological, psychological, and social dimensions. Grounded fundamentally in Virginia Henderson’s Need Theory of nursing, the CDS views dependency not merely as functional physical limitation, but as an individual’s inability to fulfill essential human needs independently due to illness, physical disability, or cognitive impairment.

The scale consists of 15 standardized items evaluated on a 5-point rating scale ranging from 1 (“Completely care dependent / completely dependent on help”) to 5 (“Almost care independent / completely independent”). Total scores range from 15 to 75, where lower summative scores designate severe care dependency and higher scores reflect functional autonomy and self-care capability. Psychometric evaluations across diverse international cohorts consistently reveal excellent internal consistency (Cronbach’s alpha typically ranging between .95 and .97) and high inter-rater reliability (intraclass correlation coefficients typically exceeding .80). Factor analytic investigations generally support a stable unidimensional structure representing general care dependency, though multidimensional configurations distinguishing somatic-functional needs from psychosocial-cognitive competencies frequently emerge in psychiatric and cognitively impaired cohorts. The CDS serves as an indispensable clinical and administrative instrument, facilitating individualized care planning, longitudinal monitoring of functional decline or rehabilitation progress, and institutional resource allocation based on nursing care intensity.

2. Keywords

Care Dependency Scale, ZorgAfhankelijkheidsschaal, functional assessment, geriatrics, nursing dependency, Henderson need theory, psychometrics, activities of daily living, institutional care, long-term care

3. Authors

The Care Dependency Scale was originally developed and psychometrically validated by a collaborative team of nursing scientists and clinical researchers based in the Netherlands:

• Ate Dijkstra, PhD, RN: Associate Professor and Senior Researcher in Nursing Science, affiliated with the Department of Health Sciences, University of Groningen, and the University Medical Center Groningen (UMCG), Groningen, Netherlands. Dr. Dijkstra spearheaded the theoretical conceptualization, item construction, and empirical validation of the Care Dependency Scale across institutional healthcare settings.
• Gerrit Buist, MSc: Research Methodologist and Clinical Nurse Specialist, affiliated with healthcare institutions in the northern Netherlands, who contributed extensively to the operational definitions of the scale criteria and its field implementation in psychogeriatric and nursing home wards.
• Theo Dassen, PhD, RN: Professor of Nursing Science at the Department of Nursing Science, Charité – Universitätsmedizin Berlin, Germany, and formerly affiliated with the Northern Centre for Healthcare Research, University of Groningen. Professor Dassen was instrumental in leading extensive cross-cultural adaptation, psychometric standardization, and widespread European implementation of the instrument.

4. Purpose

The primary purpose of the Care Dependency Scale (CDS) is to provide an objective, standardized, and theoretically grounded measurement of an individual’s care dependency within formal care environments. Professional nursing care becomes mandatory when illness, cognitive impairment, or congenital or acquired disability renders a person unable to independently satisfy their fundamental physiological and psychosocial needs. Before the establishment of the CDS, clinical assessments of functional deficit were overwhelmingly dominated by narrow activities of daily living (ADL) scales, such as the Barthel Index or the Katz Index of Independence in Activities of Daily Living. While these conventional metrics capture rudimentary motor tasks (e.g., transfers, basic feeding, and personal grooming), they routinely fail to appraise the complex cognitive, communicative, and psychosocial dimensions that necessitate intensive professional nursing surveillance and intervention.

Clinically, the CDS addresses this gap by evaluating 15 discrete functional domains spanning somatic, communicative, psychological, and social competencies. The tool functions as an observational rating scale administered by direct-care professionals (primarily registered nurses, licensed practical nurses, or specialized residential caregivers) who possess thorough observational knowledge of the patient’s habitual day-to-day functional performance. By standardizing the assessment of dependency across these 15 dimensions, the CDS enables clinicians to systematically identify specific domains where self-care deficits exist, thereby supporting the formulation of targeted, individualized nursing care plans that bolster preserved capabilities while compensating for deficits.

From an administrative and health services research perspective, the aggregate data generated by the CDS provide healthcare managers and nursing administrators with actionable data regarding ward-level case mix, overall nursing workload, and staffing requirements. Because the scale provides a quantitative continuum from complete independence to profound dependency, it facilitates longitudinal tracking of patient trajectories over time, identifying progressive decline in neurodegenerative conditions (such as Alzheimer’s disease and vascular dementia) or capturing functional recovery during post-acute geriatric rehabilitation. Furthermore, cross-national and health-economic researchers leverage the CDS to evaluate the efficacy of nursing interventions, compare organizational models of institutional care, and investigate the determinants of institutionalization across diverse health jurisdictions.

5. Psychological Construct

The construct of Care Dependency operationalized by the CDS is defined as the condition wherein an individual, due to limitations in physical, intellectual, or psychological functioning, relies on professional assistance to sustain bodily integrity, psychosocial equilibrium, and developmental self-actualization. Dijkstra and colleagues explicitly rejected the reductionist perspective that equates dependency solely with biomechanical disability. Instead, care dependency is conceptualized as a multi-tiered, biopsychosocial state arising from the dynamic interplay between the person’s functional capacity and the demands of their environment.

The construct encompasses 15 operationalized domains, structured as follows:

• Physiological and Somatic Maintenance: This dimension incorporates basic survival and self-preservation needs. Eating and drinking evaluates the patient’s capacity to recognize the need for nutrition, ingest food, chew, swallow, and regulate caloric and fluid intake without physical assistance or prompting. Incontinence measures voluntary bowel and bladder control, as well as the ability to manage continence aids independently. Body posture focuses on the maintenance and adjustment of anatomical posture while seated or lying down to avoid pressure injuries or contractures. Mobility addresses ambulatory capacity, locomotion, and independent changes of location. Day and night pattern evaluates circadian stability, distinguishing individuals who maintain healthy sleep-wake rhythms from those exhibiting severe sleep inversion, nocturnal wandering, or psychomotor agitation. Getting dressed and undressed and Hygiene evaluate complex motor planning and execution required for personal presentation, thermal protection, bathing, and oral care. Lastly, Body temperature assesses the person’s ability to maintain thermal homeostasis through behavioral adaptation, such as adjusting clothing or ambient room heating.
• Cognitive Regulation and Safety: This facet captures the psychological and cognitive faculties necessary for autonomous existence. Avoidance of danger reflects judgment, environmental hazard appraisal, and impulse control, assessing whether a patient can perceive and circumvent risks such as falls, toxic exposures, or burns without constant nursing surveillance. Learning ability evaluates cognitive plasticity, executive functioning, and memory retention, observing whether the individual can assimilate new information, retain behavioral instructions, or master adaptive strategies.
• Psychosocial and Relational Integration: Moving beyond biological maintenance, this dimension addresses higher-order human functioning. Communication examines both receptive and expressive language, assessing the patient’s ability to convey distress, voice desires, and comprehend verbal or nonverbal directives. Contact with others measures social initiation, reciprocity, and interpersonal engagement within the residential community. Sense of rules and values examines moral awareness, behavioral conformity to societal and institutional norms, and respect for collective boundaries. Finally, Daily activities and Recreational activities appraise intrinsic motivation, purposeful occupation, and the capacity to engage in meaningful work, hobbies, or leisure pursuits independently.

6. Theoretical Framework

The theoretical architecture of the Care Dependency Scale is directly rooted in the nursing philosophy and human needs model formulated by Virginia Henderson. In her seminal definition of nursing, Henderson posited that the unique function of the nurse is to assist the individual, sick or well, in the performance of those activities contributing to health or its recovery (or to a peaceful death) that the person would perform unaided if they had the necessary strength, will, or knowledge. Henderson delineated 14 fundamental human needs, encompassing biological processes (respiration, nourishment, elimination, mobility, sleep, hygiene, temperature regulation), physical safety, emotional expression, spiritual fulfillment, and occupational accomplishment.

Dijkstra, Buist, and Dassen mapped Henderson’s 14 basic needs onto a rigorous psychometric framework, expanding the conceptual model to 15 operationalized items tailored specifically to institutional healthcare contexts. The underlying theoretical postulate asserts that human beings possess an intrinsic drive toward independence and self-determination. When chronic disease, trauma, or cognitive deterioration impairs the individual’s physiological capacity (“strength”), motivation (“will”), or cognitive comprehension (“knowledge”), a state of care dependency manifests. Under this framework, dependency is not viewed pejoratively as a character flaw or passive submission, but rather as an objective state of unmet needs necessitating external professional supplementation.

The scale also interfaces with Dorothea Orem’s Self-Care Deficit Nursing Theory. Orem conceptualizes nursing as an art and science enacted when a client experiences a “self-care deficit”—an imbalance where universal and developmental self-care requisites exceed the patient’s personal “self-care agency.” The CDS acts as a clinical metric quantifying this self-care deficit. When a patient demonstrates a score of 1 on an item (e.g., Eating and drinking), Orem’s theoretical framework categorizes the nursing system required as “wholly compensatory.” Conversely, higher scores (e.g., 4 or 5) correspond to “partially compensatory” or “supportive-educative” nursing systems, where the patient maintains agency and the nurse’s role shifts toward enablement, encouragement, and environmental modification.

7. Validity

The Care Dependency Scale has undergone extensive psychometric validation across multiple healthcare settings and international cohorts, consistently establishing strong construct, criterion, convergent, and discriminant validity.

Construct and Convergent Validity: In the initial validation studies conducted by Dijkstra et al. (1996, 1999) across Dutch nursing homes and facilities for individuals with intellectual disabilities, the CDS demonstrated strong convergent validity when benchmarked against established measures of functional impairment. Total CDS scores demonstrated substantial negative correlations with instruments measuring functional impairment, such as the Barthel Index ($r = .80$ to $.86, p < .001$), indicating that higher care independence on the CDS aligns robustly with high physical ADL performance. Furthermore, CDS scores exhibited statistically significant positive correlations with global cognitive assessments, such as the Mini-Mental State Examination (MMSE; $r = .55$ to $.68, p < .001$), demonstrating that cognitive decline corresponds closely with escalating care dependency, particularly across the psychosocial, communicative, and danger-avoidance items.

Criterion and Predictive Validity: Longitudinal studies have confirmed the predictive utility of the CDS regarding clinical outcomes and resource consumption. Research conducted in German and Dutch long-term care institutions demonstrated that lower baseline CDS scores (indicating high dependency) significantly predict adverse health outcomes, including the incidence of pressure ulcers, hospital readmission rates, and institutional mortality over 12- to 24-month observation windows. Furthermore, when calibrated against actual nursing care time tracked via computerized logging systems, the CDS accounted for over 60% of the variance in direct bedside care hours, establishing criterion validity as a measure of care intensity.

Discriminant and Known-Groups Validity: The CDS effectively distinguishes between patient subgroups with differing care requirements. Significant differences ($p < .001$) in CDS scores are routinely detected across wards classified by specialized care level (e.g., somatic rehabilitation wards versus severe psychogeriatric dementia units). In validation studies among individuals with intellectual disabilities, the CDS effectively discriminated across varying levels of intellectual impairment (mild, moderate, severe, and profound), confirming that the instrument sensitively captures gradations of intellectual and behavioral reliance on caregivers.

8. Reliability

Empirical evaluations of the Care Dependency Scale demonstrate exceptionally high reliability across internal consistency, inter-rater concordance, and test-retest stability metrics.

Internal Consistency: Across multiple national and international investigations (including Dutch, German, British, Italian, Spanish, and Scandinavian cohorts), the 15-item scale has exhibited Cronbach’s alpha coefficients exceeding the standard thresholds for clinical decision-making. In the seminal study by Dijkstra et al. (1996), Cronbach’s alpha was reported at .97 for nursing home residents ($N = 345$) and .95 for residents with intellectual disabilities ($N = 286$). Subsequent international psychometric investigations (e.g., Dassen et al., 2002; Boggatz et al., 2007) have uniformly reported Cronbach’s alpha values between .93 and .98. Corrected item-total correlations across all 15 items consistently exceed .60, with the vast majority ranging between .70 and .88, confirming high internal coherence.

Inter-Rater Reliability: Because the CDS is an observational rating completed by healthcare staff, inter-rater reliability is paramount. Studies evaluating paired, blinded ratings completed by independent registered nurses and nursing assistants have yielded Intraclass Correlation Coefficients (ICC) for the total score ranging from .82 to .94. At the individual item level, Cohen’s weighted kappa ($\kappa_w$) coefficients generally range from .60 to .85, indicating substantial to near-perfect agreement. Discrepancies, when present, typically occur on more subjective psychosocial items (e.g., Sense of rules and values, Contact with others), whereas somatic items (e.g., Incontinence, Eating and drinking) consistently achieve kappa coefficients exceeding .80.

Test-Retest Stability: In stable nursing home cohorts assessed across a two-week interval without acute clinical changes, test-retest reliability coefficients have been reported at $r = .88$ to $.93$, indicating robust temporal stability when measuring chronic, underlying care needs.

9. Factor Analysis

The underlying dimensionality of the Care Dependency Scale has been explored via both Exploratory Factor Analysis (EFA) and Confirmatory Factor Analysis (CFA), leading to widespread psychometric discussion regarding whether the scale represents a unidimensional continuum or a two-factor structure.

In early exploratory factor analyses conducted by Dijkstra and colleagues, principal component analyses with varimax rotation routinely produced a strong dominant first factor explaining between 58% and 68% of the total variance, accompanied by an eigenvalue substantially greater than 8.0 (often exceeding 9.5). Because all 15 items exhibited high factor loadings on this primary dimension (typically $lambda > .65$), the authors initially argued for a parsimonious, unidimensional model of care dependency, justifying the clinical aggregation of all 15 items into a single composite score.

However, subsequent confirmatory factor analyses, particularly in cross-national validations (e.g., Dijkstra et al., 1999; Suhonen et al., 2011), indicated that a two-factor model provides superior fit to the observed data. The two distinct yet moderately correlated latent factors identified are:

• Factor 1: Somatic / Physical Care Dependency: Comprising items such as Eating and drinking, Incontinence, Body posture, Mobility, Getting dressed and undressed, and Hygiene. Factor loadings for these somatic items consistently exceed .75 on this latent dimension.
• Factor 2: Psychosocial / Cognitive Care Dependency: Comprising items such as Avoidance of danger, Communication, Contact with others, Sense of rules and values, Daily activities, Recreational activities, and Learning ability. Items such as Day and night pattern and Body temperature occasionally demonstrate cross-loadings, reflecting their mixed physiological and neurobehavioral determinants.

In structural equation modeling evaluating the two-factor specification across European nursing home populations, model fit indices achieved acceptable to excellent benchmarks: Comparative Fit Index (CFI) > .95, Tucker-Lewis Index (TLI) > .94, and Root Mean Square Error of Approximation (RMSEA) ≤ .07. While subscale scoring along these two dimensions is occasionally utilized in specialized geriatric psychiatry studies, standard clinical practice continues to rely on the summative unidimensional total score due to its high diagnostic efficiency and prognostic power.

10. Instrument / Measurement Tool

The Care Dependency Scale is structured as an observational assessment tool completed by healthcare providers based on their clinical observation and knowledge of the care recipient. Below are the operational measurement parameters:

• Instrument Name: Care Dependency Scale (CDS); Dutch: ZorgAfhankelijkheidsschaal.
• Target Populations: Older adults residing in nursing homes, hospitalized geriatric and medical patients, rehabilitation clients, and adults receiving residential or community-based intellectual disability care.
• Administration Method: Observational rating by professional healthcare staff (registered nurses, licensed practical nurses, nursing assistants, or direct residential support workers) who have cared for the patient for a sufficient duration (typically at least one to two weeks) to reliably judge habitual performance.
• Item Count: 15 standardized items.
• Authentic Response Scale: 5-point rating scale:
  • 1 = Completely care dependent / completely dependent on help
  • 2 = To a great extent care dependent
  • 3 = Partially care dependent
  • 4 = To a limited extent care dependent
  • 5 = Almost care independent / completely independent
• Scoring and Quantification:
  • Each item is scored from 1 to 5 based on standardized criterion descriptions.
  • The total scale score is obtained by summing the numerical ratings across all 15 items.
  • Total Score Range: 15 to 75.
  • Interpretation: Lower scores represent severe care dependency (high need for professional nursing support), whereas higher scores represent functional independence and self-care capability (minimal need for assistance).
• Versions: Two core validated Dutch variants exist sharing identical item stems: the nursing home version (verpleeghuisversie) and the intellectual disability version (verstandelijke gehandicaptenzorg), accompanied by specific criteria and guidelines tailored to each context.

11. Permissions & Fee and Test Year

The Care Dependency Scale was originally established and published in 1996 by Dr. Ate Dijkstra, Gerrit Buist, and Prof. Dr. Theo Dassen in the Netherlands. The scale was developed under the auspices of academic research programs funded by Dutch healthcare research initiatives and the University of Groningen.

Licensing and Academic Use: The CDS is protected by intellectual property copyright held by the primary authors and their academic institutions. However, the authors have historically maintained an open-access philosophy for non-commercial clinical, academic, educational, and scientific research purposes. Researchers wishing to employ the CDS in clinical trials, health services studies, or academic dissertations are generally permitted to use the instrument without license fees, provided that appropriate bibliographic citation is accorded to the foundational validation literature. For commercial software integration, electronic health record (EHR) vendor deployment, or proprietary health system implementations, formal written permission and licensing agreements should be sought directly from the primary author (Dr. Ate Dijkstra) or through the designated institutional technology transfer office at the University of Groningen / University Medical Center Groningen.

12. References

• Boggatz, T., Dijkstra, A., Lohrmann, C., & Dassen, T. (2007). The Care Dependency Scale: Measuring basic care needs of elderly patients. Scandinavian Journal of Caring Sciences, 21(1), 111–118. https://doi.org/10.1111/j.1471-6712.2007.00440.x
• Dassen, T., Dijkstra, A., & Buist, G. (1996). The Care Dependency Scale: Development and psychometric properties. In Proceedings of the International Nursing Research Conference, Groningen.
• Dijkstra, A., Buist, G., & Dassen, T. (1996). ZorgAfhankelijkheidsschaal (ZAS): Handleiding en verantwoording [Care Dependency Scale (CDS): Manual and justification]. Northern Centre for Healthcare Research, University of Groningen.
• Dijkstra, A., Buist, G., & Dassen, T. (1998). Operationalization of the concept of ‘care dependency’ for use in long-term care facilities. Australian Journal of Advanced Nursing, 15(4), 16–23.
• Dijkstra, A., Smith, J., & White, M. (1999). Measuring care dependency with the Care Dependency Scale: A confirmation of its psychometric properties. Journal of Advanced Nursing, 30(4), 899–907. https://doi.org/10.1046/j.1365-2648.1999.01160.x
• Henderson, V. (1966). The Nature of Nursing: A Service in the Individual’s Mastery of Needs. Macmillan.
• Suhonen, R., Stolt, M., Dijkstra, A., Katajisto, J., & Leino-Kilpi, H. (2011). The Care Dependency Scale (CDS) in older people: A systematic review of psychometric properties. International Journal of Older People Nursing, 6(4), 285–299. https://doi.org/10.1111/j.1748-3743.2011.00287.x

13. Items of the Scale (Questionnaire)