Description

The Illness Behaviour Questionnaire (IBQ) is a psychometric instrument designed to assess individuals’ cognitive, emotional, and behavioral responses to illness and physical symptoms. Originally developed by Pilowsky and Spence, the questionnaire evaluates the ways in which people perceive, interpret, and respond to illness, regardless of the severity of any underlying medical condition.

The IBQ examines illness behavior, defined as the manner in which individuals monitor bodily symptoms, interpret health-related experiences, seek medical care, comply with treatment recommendations, and cope with the impact of illness on daily life. The instrument assesses dimensions such as health concern, disease conviction, symptom perception, help-seeking behavior, emotional responses to illness, and the influence of health problems on everyday functioning.

The questionnaire is widely used in clinical psychology, psychosomatic medicine, psychiatry, behavioral medicine, and health psychology, providing valuable information about the psychological factors that influence illness perception and health-related behaviors.

Analysis and Use of Data

The analysis of the IBQ is based on participants’ responses to a series of statements assessing different aspects of illness behavior. Responses are scored according to the administration guidelines, allowing the calculation of both overall scores and subscale scores.

The resulting data can be used to investigate the relationship between illness behavior and psychological variables such as anxiety, depression, quality of life, somatization, chronic pain, functional somatic symptoms, treatment adherence, healthcare utilization, psychological resilience, and health perceptions. The questionnaire is also useful for identifying maladaptive illness beliefs and behaviors that may interfere with recovery, treatment adherence, or everyday functioning.

Psychometric evaluation of the IBQ typically includes the assessment of internal consistency using Cronbach’s alpha, test–retest reliability, and construct validity through exploratory or confirmatory factor analysis. In addition, convergent and discriminant validity are commonly examined by comparing IBQ scores with other measures of health anxiety, somatization, illness perceptions, and psychological adjustment.

Objective

The primary objective of the Illness Behaviour Questionnaire (IBQ) is to provide a reliable and valid assessment of how individuals perceive and respond to illness and physical symptoms. More specifically, the instrument aims to:

  • Assess illness-related behaviors and attitudes.
  • Identify maladaptive beliefs regarding health and physical symptoms.
  • Evaluate factors influencing help-seeking behavior and treatment adherence.
  • Support clinical assessment and individualized intervention planning.
  • Facilitate research on health psychology, psychosomatic medicine, and illness behavior.

Scoring

The IBQ consists of a series of items scored according to the administration guidelines of the instrument. Total scores are calculated by summing participants’ responses, while separate subscale scores may also be computed to assess specific dimensions of illness behavior.

Higher scores generally indicate greater illness concern, stronger preoccupation with physical symptoms, and a higher likelihood of maladaptive illness-related beliefs and behaviors. Lower scores suggest more adaptive illness perceptions, realistic interpretations of symptoms, and better psychological adjustment to health conditions.

For research purposes, it is recommended that the psychometric properties of the instrument be evaluated through Cronbach’s alpha, test–retest reliability, and construct validity analyses.

Applications

The Illness Behaviour Questionnaire is widely used in clinical psychology, psychiatry, psychosomatic medicine, health psychology, and behavioral medicine. It has been applied in studies investigating somatization, chronic pain, medically unexplained symptoms, health anxiety, quality of life, treatment adherence, and healthcare utilization.

In clinical practice, the IBQ assists healthcare professionals in identifying maladaptive illness behaviors and dysfunctional health beliefs, planning appropriate psychological or psychoeducational interventions, and evaluating treatment outcomes aimed at improving patients’ adaptation to illness.

References

Wessely, S., Nimnuan, C., & Sharpe, M. (1997). Functional Somatic Syndromes: One or Many? The Lancet, 350(9078), 136–139.

Pilowsky, I., & Spence, N. D. (1983). Manual for the Illness Behaviour Questionnaire (IBQ). University of Adelaide.

Pilowsky, I. (1978). A General Classification of Abnormal Illness Behaviours. British Journal of Medical Psychology, 51, 131–137.

Rief, W., & Broadbent, E. (2007). Explaining Medically Unexplained Symptoms: Models and Mechanisms. Psychological Bulletin, 133(5), 821–841.