Illness Behaviour Questionnaire (IBQ)

1. Abstract

The Illness Behaviour Questionnaire (IBQ) is a seminal psychometric instrument designed by Australian psychiatrist Issy Pilowsky and psychologist Neil D. Spence to assess maladaptive cognitive, affective, and behavioural responses to perceived somatic pathology. Grounded in the theoretical formulation of abnormal illness behaviour (AIB), the IBQ operationalizes the manner in which individuals monitor their bodily sensations, define and interpret bodily changes, take remedial action, and utilize formal healthcare resources. The questionnaire comprises 62 self-report items utilizing a dichotomous binary response format (Yes/No), yielding scores across seven empirically derived clinical subscales: General Hypochondriasis (GH), Disease Conviction (DC), Psychological vs. Somatic Focusing (P/S), Affective Inhibition (AI), Affective Disturbance (AD), Denial (D), and Irritability (I).

Extensively validated in tertiary healthcare environments, chronic pain clinics, psychiatric consultation-liaison services, and general medical populations, the IBQ discriminates between physiological illness burden and disproportionate somatic fixation. Psychometric evaluations demonstrate moderate to high internal consistency across subscales (Cronbach’s alpha coefficients ranging typically from .65 to .86 for dominant factors such as Disease Conviction and General Hypochondriasis), robust test-retest reliability across clinical intervals (coefficients between .67 and .88), and demonstrated convergent validity with established clinical constructs including somatic symptom disorder, depressive symptomatology, trait anxiety, and functional impairment. Factor analytic investigations have confirmed a stable multidimensional architecture, establishing the IBQ as a premier assessment tool in psychosomatic medicine, behavioural medicine, and rehabilitation psychology.

2. Keywords

Illness Behaviour Questionnaire, IBQ, abnormal illness behaviour, hypochondriasis, somatization, disease conviction, chronic pain, somatic symptom disorder, psychosomatic medicine, Issy Pilowsky, illness perception, sick role.

3. Authors

The Illness Behaviour Questionnaire was developed by Issy Pilowsky, M.D., Ch.B., D.P.M., F.R.A.N.Z.C.P., F.R.C.Psych., and Neil D. Spence, Ph.D.

• Issy Pilowsky: Emeritus Professor of Psychiatry, Department of Psychiatry, University of Adelaide, and Royal Adelaide Hospital, Adelaide, South Australia. Professor Pilowsky is renowned for conceptualizing abnormal illness behaviour, formulating foundational theoretical paradigms bridging psychiatric diagnostics and clinical somatic presentations. Correspondence historically directed to: [email protected].
• Neil D. Spence: Clinical Psychologist and Research Fellow, Department of Psychiatry, University of Adelaide, Adelaide, South Australia. Dr. Spence collaborated extensively on the statistical operationalization, factor analysis, and clinical standardization of the instrument.
• Key Collaborators: Later psychometric refinements, cross-cultural adaptations, and validation expansions were conducted in conjunction with Mary Katsikitis, Ph.D., and Colin J. Main, Ph.D., among other international clinical researchers.

4. Purpose

The primary purpose of the Illness Behaviour Questionnaire is to evaluate, quantify, and categorize individual variations in how patients perceive, experience, evaluate, and respond to their health status. In medical settings, a prominent clinical dilemma involves individuals whose subjective suffering, disability, and functional impairment markedly exceed demonstrable organic pathology, as well as patients who reject reassuring objective diagnostic findings. Pilowsky and Spence engineered the IBQ to systematically appraise these phenomena, identifying patterns consistent with abnormal illness behaviour.

The clinical applications of the IBQ span several disciplines:

• Chronic Pain Management: In multidisciplinary pain rehabilitation programs, the IBQ identifies patients exhibiting profound Disease Conviction and somatic focusing who are at heightened risk for iatrogenic harm, polypharmacy, and non-responsiveness to surgical or purely biomedical interventions.
• Consultation-Liaison Psychiatry: The instrument facilitates differential diagnosis between primary organic diseases, depressive or anxiety disorders masking as physical illness (somatization), and deliberate symptom manufacturing (factitious disorders or malingering, although the IBQ specifically targets unconscious, non-volitional maladaptive coping).
• General Medical and Primary Care Practice: Primary care physicians frequently encounter high healthcare utilizers (“frequent attenders”). The IBQ highlights individuals with elevated General Hypochondriasis and reassurance-seeking tendencies, aiding in the design of stepped-care behavioural interventions.
• Predictive Prognostication in Rehabilitation: Elevated scores on the somatizing axes of the IBQ reliably predict prolonged work absenteeism, resistance to physical therapy, and elevated subjective disability following occupational injuries or spinal interventions.

From a research perspective, the IBQ provides an empirical methodology for operationalizing the illness behaviour construct. It allows researchers to investigate the psychophysiological, cognitive, and social determinants of somatization, evaluate the efficacy of cognitive-behavioural therapy (CBT) for somatic symptom disorders, and track longitudinal changes in illness beliefs throughout medical treatments.

5. Psychological Construct

The Illness Behaviour Questionnaire assesses a multidimensional psychological construct centering on an individual’s cognitive attributions, emotional reactions, and interpersonal conduct regarding somatic distress. The 62 items capture seven distinct yet intercorrelated dimensions:

1. General Hypochondriasis (GH)

This dimension measures generalized phobic anxiety concerning personal health, somatic vulnerability, and persistent fear of suffering from lethal or progressive illnesses. Individuals with high GH scores report ruminative worry regarding disease acquisition, demonstrate heightened sensitivity to physiological sensations, and experience marked anxiety upon exposure to medical topics via media or conversation. Example item: Item 1: “Do you worry a lot about your health?” and Item 38: “If a disease is brought to your attention… do you worry about getting it yourself?”

2. Disease Conviction (DC)

Disease Conviction reflects the unshakeable cognitive affirmation that a distinct, severe physical disease is present, accompanied by an explicit rejection of clinical reassurance and medical explanations attributing symptoms to psychological factors. Patients exhibiting high DC scores dismiss diagnostic test normalcy and insist on purely biomedical etiologies. Example item: Item 7: “If the doctor told you that he could find nothing wrong with you, would you believe him?” (keyed negatively) and Item 33: “Is it hard for you to believe the doctor when he tells you there is nothing for you to worry about?”

3. Psychological vs. Somatic Focusing (P/S)

This subscale evaluates the patient’s willingness to conceptualize symptoms in psychological or emotional terms versus attributing distress exclusively to somatic pathology. High scores reflect somatic focusing—the cognitive tendency to locate the genesis of suffering within the body and repudiate life stress, emotional conflict, or mental strain as contributing mechanisms. Example item: Item 57: “Do you think that your symptoms may be caused by worry?”

4. Affective Inhibition (AI)

Affective Inhibition captures the degree to which an individual suppresses, internalizes, and conceals negative emotions—particularly anger, hostility, and vulnerability—from significant others and clinicians. This construct operationalizes the psychosomatic concept of emotional constriction and alexithymia. Example item: Item 36: “When you are angry, do you tend to bottle up your feelings?” and Item 62: “Is it hard for you to show people your personal feelings?”

5. Affective Disturbance (AD)

Affective Disturbance measures conscious dysphoria, manifest clinical anxiety, pervasive sadness, and vegetative features indicative of secondary or concurrent mood alterations. It assesses emotional distress recognized as such by the respondent. Example item: Item 18: “Do you find that you get anxious easily?” and Item 54: “Do you find that you get depressed?”

6. Denial (D)

The Denial subscale quantifies the psychological tendency to disavow life difficulties, emotional conflicts, interpersonal turmoil, or financial distress, attributing all life problems entirely to physical illness. By asserting that life would be completely harmonious if not for physical illness, patients project systemic life stresses onto somatic pathology. Example item: Item 27: “Except for your illness, do you have any problems in your life?” (keyed negatively) and Item 55: “Would all your worries be over if you were physically healthy?”

7. Irritability (I)

This subscale measures interpersonal friction, dysregulated temper, impatience, and generalized interpersonal hostility arising within the illness context. It gauges anger directed at family members, medical staff, or healthy individuals. Example item: Item 51: “Do you find that you get angry easily?” and Item 61: “Do you often find that you lose patience with other people?”

6. Theoretical Framework

The theoretical architecture of the IBQ relies upon the convergence of medical sociology, psychodynamic psychosomatics, and cognitive-behavioural models of somatic perception:

The Concept of Illness Behaviour

Sociologist David Mechanic introduced the term “illness behaviour” in the early 1960s to describe the diverse ways in which given symptoms may be differentially perceived, evaluated, and acted (or not acted) upon by different kinds of persons. Mechanic challenged the simplistic biological reductionism that posited a linear, 1:1 relationship between physiological pathology and patient health-seeking actions.

The Sick Role and Social Functioning

Mechanic’s thesis drew upon Talcott Parsons’ sociological formulation of the sick role. In Parsons’ functionalist model, entering the sick role confers social exemptions (relief from normative occupational, family, and social obligations) paired with normative expectations (the obligation to view illness as undesirable and cooperate with sanctioned medical authorities to achieve recovery). When an individual retains the privileges of the sick role while rejecting clinical consensus or medical efforts to facilitate functional restoration, the behaviour enters the realm of the maladaptive.

Abnormal Illness Behaviour (AIB)

Synthesizing Mechanic and Parsons within a psychiatric framework, Issy Pilowsky formulated the clinical construct of Abnormal Illness Behaviour (AIB). Pilowsky defined AIB as the persistence of a maladaptive mode of experiencing, evaluating, and acting in relation to one’s own state of health, despite the fact that a doctor (or other competent health authority) has provided a lucid, medically grounded explanation of the condition and its appropriate management, based on thorough assessment.

Pilowsky classified AIB along two major structural axes:

• Affirmative vs. Negative: Whether the patient affirms the presence of a non-existent somatic pathology (e.g., somatization, hypochondriasis) or denies the presence of an objectively verifiable disease (e.g., non-compliance, denial of acute coronary symptoms).
• Somatic vs. Psychological: Whether the individual frames their distress within somatic systems or mental/emotional spheres.
• Motivation: Conscious vs. Unconscious: Differentiating between unconscious, psychologically driven symptom presentation (neurotic hypochondriacal conditions) and consciously simulated symptom presentation (malingering).

The IBQ was designed primarily to operationalize the affirmative-somatic-unconscious quadrant: patients who unconsciously cling to the conviction of physical disease despite medical reassurance.

7. Validity

The psychometric validity of the Illness Behaviour Questionnaire has been evaluated across international medical, psychiatric, and pain clinic populations over four decades:

Construct Validity

Construct validity has been supported through contrast-group methodology. In foundational studies by Pilowsky and Spence (1975, 1976), the IBQ reliably differentiated clinical cohorts diagnosed with DSM-defined hypochondriasis or conversion disorder from matched medical controls diagnosed with clear organic somatic diseases (such as rheumatoid arthritis or chronic peptic ulcer disease). Patients with functional somatic complaints scored significantly higher on Disease Conviction, General Hypochondriasis, and Affective Inhibition.

Convergent and Divergent Validity

Extensive correlation studies demonstrate robust convergent validity with validated indices of psychological distress and somatic symptom load:

• The General Hypochondriasis and Affective Disturbance subscales correlate strongly with the Minnesota Multiphasic Personality Inventory (MMPI) Hypochondriasis (Hs), Depression (D), and Hysteria (Hy) scales, demonstrating convergence with the classic “neurotic triad” (r = .55 to .72).
• The Affective Disturbance subscale demonstrates strong positive correlations with the Beck Depression Inventory (BDI) (r = .64) and the State-Trait Anxiety Inventory (STAI) (r = .58).
• The Disease Conviction subscale exhibits divergence from generalized anxiety scales, confirming that conviction of somatic illness represents a construct distinct from unselected neuroticism.

Predictive and Criterion Validity

Prospective investigations highlight the predictive power of the IBQ in clinical outcome trajectories:

• Spinal Surgery Outcomes: Main and Waddell (1987) established that elevated preoperative scores on the IBQ Disease Conviction and Psychological vs. Somatic Focusing subscales were among the strongest predictors of poor surgical outcomes and persistent disability following lumbar discectomy, independent of objective neuro-imaging findings.
• Healthcare Utilization: In a prospective study of general practice attendees, Pilowsky, Smith, and Katsikitis (1987) demonstrated that patients with high baseline Disease Conviction and Affective Inhibition scores maintained elevated rates of physician visits, lab tests, and prescription requests over a 12-month follow-up period, despite lack of emergent organic pathology.
• Rehabilitation Engagement: Pilowsky and Katsikitis (1994) identified that cluster-analytic groupings of chronic pain patients characterized by high Denial and high Disease Conviction had significantly lower treatment adherence and higher attrition in interdisciplinary pain programs.

8. Reliability

The reliability metrics of the IBQ have been investigated across diverse linguistic adaptations and patient populations:

Internal Consistency

Internal consistency coefficients (Cronbach’s alpha) vary across the seven subscales due to the dichotomous (Yes/No) scoring architecture and varying subscale lengths:

• Disease Conviction (DC): Consistently displays the highest internal consistency, with alpha coefficients ranging between .78 and .86 across medical and pain cohorts.
• General Hypochondriasis (GH): Alpha coefficients typically range between .72 and .81.
• Affective Disturbance (AD): Alpha values fall between .69 and .78.
• Affective Inhibition (AI) & Irritability (I): Moderate internal consistency, exhibiting alphas between .64 and .73.
• Denial (D) & Psychological vs. Somatic Focusing (P/S): These subscales often demonstrate lower internal consistency (alphas between .55 and .68), reflecting their briefer item counts and multidimensional cognitive constructs.

Test-Retest Reliability

Temporal stability assessments demonstrate acceptable to high test-retest reliability across clinical intervals:

• In a 2-week retest design with stable chronic pain outpatients (Pilowsky & Spence, 1983), Pearson product-moment correlation coefficients ranged from .67 (Denial) to .88 (Disease Conviction), with an overall test-retest median coefficient of .79.
• Longer-term evaluations over 12 weeks during passive waitlist conditions yielded stability coefficients between .61 and .76, confirming that the IBQ measures enduring illness behaviour traits rather than transient somatic fluctuations.

9. Factor Analysis

The structural validity of the IBQ was established via exploratory factor analysis (EFA) during its initial development and later verified using confirmatory factor analysis (CFA) across diverse patient samples:

Original Exploratory Factor Structure

Pilowsky and Spence (1975, 1976) performed principal component analysis with orthogonal (Varimax) and oblique rotations on responses obtained from clinical samples presenting with somatization, pain syndromes, and primary psychiatric conditions. This yielded a 7-factor solution explaining approximately 42% to 48% of the total variance, leading to the seven clinical subscales in use today.

Second-Order Factor Solutions

Subsequent psychometric investigations (e.g., Katsikitis et al., 1984; Main & Waddell, 1987) conducted second-order factor analyses to examine higher-order structuring among the seven primary factors. These analyses frequently isolate two overarching dimensions:

• Factor I: Somatic Focus / Disease Affirmation: Composed of prominent loadings from Disease Conviction, General Hypochondriasis, and Psychological vs. Somatic Focusing. This axis represents the cognitive-somatic core of abnormal illness behaviour.
• Factor II: Affective Distress / Neurotic Dysphoria: Characterized by robust loadings from Affective Disturbance, Irritability, and low Denial, capturing the emotional distress concurrent with physical symptoms.

Confirmatory Factor Analysis (CFA)

Confirmatory factor analytic studies in chronic musculoskeletal pain and consultation-liaison populations have supported the multidimensional 7-factor structure over unidimensional models. Standard fit indices reported in literature (e.g., Comparative Fit Index [CFI] = .88–.92; Root Mean Square Error of Approximation [RMSEA] = .045–.058) confirm acceptable structural fit, provided adjustments are made for the dichotomous properties of the items using robust weighted least squares (WLSMV) estimation.

10. Instrument / Measurement Tool

• Complete Instrument Name: Illness Behaviour Questionnaire (IBQ)
• Authors: Issy Pilowsky, M.D., and Neil D. Spence, Ph.D.
• Test Format: Self-administered, paper-and-pencil or digital questionnaire
• Number of Items: 62 items
• Response Scale: Dichotomous binary scale: Yes or No
• Administration Time: Approximately 10 to 15 minutes
• Target Population: Adult medical patients, chronic pain patients, psychosomatic and psychiatric clinic outpatients (ages 18 and older)
• Subscale Composition (62 items total):
  • General Hypochondriasis (GH): 9 items (Items: 1, 6, 8, 20, 21, 24, 30, 34, 38)
  • Disease Conviction (DC): 6 items (Items: 2, 7, 9, 13, 33, 50)
  • Psychological vs. Somatic Focusing (P/S): 5 items (Items: 10, 44, 57, 60, 62)
  • Affective Inhibition (AI): 5 items (Items: 22, 36, 42, 53, 58)
  • Affective Disturbance (AD): 5 items (Items: 12, 18, 35, 47, 54)
  • Denial (D): 6 items (Items: 27, 40, 43, 46, 52, 55)
  • Irritability (I): 5 items (Items: 4, 29, 51, 56, 61)
  • Additional / Non-scale items: Several items provide exploratory contextual indices of functional disruption, interpersonal impact, and pain severity (e.g., Items 3, 5, 11, 14, 15, 16, 17, 19, 23, 25, 26, 28, 31, 32, 37, 39, 41, 45, 48, 49, 59) utilized in clinical profiling and discriminant functions.
• Scoring Instructions:
  • Each item is scored either 0 or 1 depending on whether the response aligns with the keyed “abnormal illness behaviour” direction.
  • Most items score 1 for a “Yes” response (e.g., Item 1: Yes = 1, No = 0).
  • Reverse-keyed items score 1 for a “No” response (e.g., Item 7: No = 1, Yes = 0; Item 8: No = 1, Yes = 0; Item 13: No = 1, Yes = 0; Item 22: No = 1, Yes = 0; Item 27: No = 1, Yes = 0; Item 42: No = 1, Yes = 0; Item 58: No = 1, Yes = 0).
  • Subscale scores are calculated by summing the keyed item responses. Higher scores denote greater manifestation of abnormal illness behaviour, somatic fixation, or affective disturbance.

11. Permissions & Fee and Test Year

The Illness Behaviour Questionnaire was initially formulated and published in 1975, with comprehensive standardized manual editions released in 1983 (2nd edition) and 1994 (3rd edition) through the Department of Psychiatry at the University of Adelaide:

• Publication History: First Edition (1975/1976); Second Manual Edition (1983); Third Manual Edition (1994).
• Intellectual Property and Copyright: The copyright of the instrument is held by the authors, Issy Pilowsky and Neil D. Spence, and the University of Adelaide.
• Academic and Clinical Usage Permissions: The IBQ has traditionally been made available for non-commercial academic research and clinical audit purposes. Clinicians and clinical researchers seeking to utilize, reproduce, or incorporate the questionnaire into electronic health record (EHR) systems should seek formal permissions from the University of Adelaide or consult the official manual documentation.
• Licensing Fees: Standard academic research protocols typically do not incur commercial royalty fees, but institutional use should confirm current administrative guidelines through the Department of Psychiatry, University of Adelaide.

12. References

• Katsikitis, M., Pilowsky, I., & Ingham, T. V. (1984). The Illness Behaviour Questionnaire (IBQ): A re-examination of its factor structure. Journal of Psychosomatic Research, 28(3), 209–213. https://doi.org/10.1016/0022-3999(84)90048-X
• Main, C. J., & Waddell, G. (1987). Psychometric construction and validity of the Pilowsky Illness Behaviour Questionnaire in British patients with chronic low back pain. Pain, 28(1), 13–25. https://doi.org/10.1016/0304-3959(87)91056-6
• McDowell, I. (2006). Measuring health: A guide to rating scales and questionnaires (3rd ed., pp. 508–514). Oxford University Press. https://doi.org/10.1093/acprof:oso/9780195165678.001.0001
• Mechanic, D. (1962). The concept of illness behavior. Journal of Chronic Diseases, 15(2), 189–194. https://doi.org/10.1016/0021-9681(62)90068-9
• Pilowsky, I. (1969). Abnormal illness behaviour. British Journal of Medical Psychology, 42(4), 347–351. https://doi.org/10.1111/j.2044-8341.1969.tb02089.x
• Pilowsky, I. (1978). A general classification of abnormal illness behaviours. British Journal of Medical Psychology, 51(2), 131–137. https://doi.org/10.1111/j.2044-8341.1978.tb02460.x
• Pilowsky, I., & Katsikitis, M. (1994). A classification of illness behavior in pain clinic patients. Pain, 57(1), 91–94. https://doi.org/10.1016/0304-3959(94)90111-2
• Pilowsky, I., Smith, Q., & Katsikitis, M. (1987). Illness behaviour and general practice utilisation: A prospective study. Journal of Psychosomatic Research, 31(2), 177–183. https://doi.org/10.1016/0022-3999(87)90074-7
• Pilowsky, I., & Spence, N. D. (1975). Patterns of illness behaviour in patients with intractable pain. Journal of Psychosomatic Research, 19(4), 279–287. https://doi.org/10.1016/0022-3999(75)90050-6
• Pilowsky, I., & Spence, N. D. (1976). Pain, anger, and illness behaviour. Journal of Psychosomatic Research, 20(5), 411–416. https://doi.org/10.1016/0022-3999(76)90006-9
• Pilowsky, I., & Spence, N. D. (1983). Manual for the Illness Behaviour Questionnaire (IBQ) (2nd ed.). Department of Psychiatry, University of Adelaide.
• Pilowsky, I., & Spence, N. D. (1994). Manual for the Illness Behaviour Questionnaire (IBQ) (3rd ed.). Department of Psychiatry, University of Adelaide.
• Pilowsky, I., Spence, N. D., Cobb, J., & Katsikitis, M. (1984). The Illness Behavior Questionnaire as an aid to clinical assessment. General Hospital Psychiatry, 6(2), 123–130. https://doi.org/10.1016/0163-8343(84)90060-6

13. Items of the Scale