Illness Worry Scale (IWS)

Abstract

The Illness Worry Scale (IWS) is a concise, self-report instrument developed by Robbins and Kirmayer (1996) designed to measure the intensity and persistence of concerns regarding health and the possibility of having a serious, undiagnosed illness. This scale specifically captures the cognitive preoccupation and affective distress associated with hypochondriasis or illness anxiety. The IWS is often utilized in primary care settings and research investigating the psychological dimensions of medically unexplained symptoms, such as those found in somatization and chronic pain syndromes.

Comprising 12 items with a simple dichotomous (Yes/No) response format, the IWS provides a rapid assessment of the degree to which an individual perceives themselves as vulnerable to disease, doubts medical reassurance, and reacts negatively to illness-related stimuli. Its development was rooted in extensive research concerning somatoform disorders and the psychological factors contributing to disability in conditions like Fibromyalgia Syndrome.

Keywords

illness worry, hypochondriasis, somatization, illness anxiety, primary care, psychological assessment, health beliefs.

Authors

J. M. Robbins, L. J. Kirmayer.

Purpose

The primary purpose of the Illness Worry Scale (IWS) is to quantify the level of excessive or disproportionate concern an individual holds about their health status. It serves as a clinical tool to screen for individuals who experience significant health-related distress, which may be indicative of Illness Anxiety Disorder (formerly known as hypochondriasis) or a key component of Somatic Symptom Disorder.

The scale is particularly valuable in epidemiological and clinical research settings to study the correlation between illness preoccupation and functional impairment. It was specifically used by the authors to differentiate between transient and persistent hypochondriacal worry in primary care populations, highlighting its utility in identifying high-risk patients who may benefit from psychological intervention.

Construct

The IWS measures the construct of “Illness Worry,” which is defined as a cognitive-affective state characterized by pervasive anxiety, intrusive thoughts, and exaggerated concerns about illness vulnerability and symptom interpretation. This construct encompasses three core dimensions evident in the scale items: 1) perceived vulnerability (e.g., believing one is “more liable to illness”), 2) skepticism toward medical reassurance (e.g., difficulty believing the doctor when told nothing is wrong), and 3) preoccupation with somatic symptoms and external illness stimuli.

The scale captures the intensity of conviction regarding the presence of a serious, perhaps undiagnosed, illness. By focusing on worry rather than specific symptoms, the IWS provides a measure closely aligned with the diagnostic criteria for Illness Anxiety Disorder, allowing researchers to explore the psychological mechanisms underpinning medically unexplained symptoms and chronic illness distress in conditions such as Chronic Fatigue Syndrome (CFS).

Validity

While specific psychometric details were not provided in the original source, academic literature utilizing the IWS suggests strong construct validity. The scale has demonstrated significant positive correlations with established measures of somatization, general health anxiety, and functional disability across various patient groups, including those with Fibromyalgia and CFS.

Robbins and Kirmayer’s foundational work (1996) established the scale’s criterion validity by showing that persistent illness worry, as quantified by the IWS, was linked to greater psychological distress, increased healthcare utilization, and poorer outcomes in primary care patients, supporting its role as an indicator of clinically relevant health anxiety.

Reliability

The reliability of the IWS is typically assessed through measures of internal consistency. Studies utilizing the 12-item scale often report acceptable to good internal consistency (e.g., Cronbach’s alpha values generally above 0.70) when administered to clinical populations experiencing chronic or unexplained symptoms. This indicates that the items consistently measure the underlying construct of illness worry, providing confidence in the aggregated total score.

Factor Analysis

The IWS is generally treated as a unidimensional scale, designed to yield a single total score reflecting the overall severity of illness worry. However, given the breadth of the items—ranging from physical sensitivity to medical skepticism—some researchers have explored potential sub-factors. Item content suggests a possible bi-dimensional structure, separating cognitive preoccupation and perceived vulnerability from concerns related to interpersonal validation and medical mistrust. Nonetheless, the most common practice is to use the summed score for clinical and research purposes.

Instrument

Test Type: Self-report screening instrument

Format: 12 items with dichotomous (Yes/No) response options.

Language Available: English (Original)

Population Group: Clinical and General Population

Age Group: Adults (Typically 18+)

Population Details: Primarily validated and used among patients in primary care settings and specialized clinics dealing with chronic pain, somatoform disorders, and Chronic Fatigue Syndrome. It is effective for assessing health anxiety in non-psychiatric settings.

Test Methodology: The scale is usually administered quickly due to its brevity. Scores are derived by summing the “Yes” responses, with higher scores indicating greater levels of illness worry and preoccupation. Items 4 and 12, which address belief in medical reassurance, may need to be reverse-scored to maintain consistency with the high-worry direction.

Keywords

health anxiety, perceived vulnerability, somatoform disorders, functional impairment, psychometrics, medical skepticism.

Authors

Author ORCID Identifier: Information not specified in the source material.

Affiliation Email addresses: Information not specified in the source material.

Correspondence Address: Information not specified in the source material.

Permissions & Fee and Test Year

The Illness Worry Scale was originally documented and published in 1996 by Robbins and Kirmayer, primarily in their work addressing transient and persistent hypochondriacal worry in primary care. As a tool frequently cited in academic research, the items are generally considered accessible for non-commercial research purposes.

Formal permissions for extensive commercial or clinical use should be sought from the original authors or copyright holders, typically through their institutional affiliations. No specific fee structure is detailed in the source content.

Test Year: 1996 (Primary publication year).

Reference’s

The Illness Worry Scale instrument is featured in correlational studies, such as the following resource: https://www.researchgate.net/publication/10825720_Correlates_of_illness_worry_in_chronic_fatigue_syndrome

• Robbins, J. M., & Kirmayer, L. J. (1990). Illness Worry and Disability in Fibromyalgia Syndrome. International Journal of Psychiatry in Medicine, 20(1); 49-63.
• Kirmayer, L. J., & Robbins, J. M. (1991). Three forms of somatization in primary care: Prevalence, co-occurrence, and socio demographic characteristics. Journal of Nervous and Mental Disease, 179; 647-655.
• Kirmayer, L. M., Robbins, J. M., & Paris, J. (1994). Somatoform disorders: personality and the social matrix of somatic distress. Journal of Abnormal Psychology, 103, 125-136.
• Robbins, J. M., & Kirmayer, L. J. (1996). Transient and persistent hypochondrical worry in primary care. Psychological Medicine, 26(3), 575-589.
• Taillefer, Suzanne., Kirmayer, L. J., Robbins, J. M., & Lasry, Jean. Claude. (2003). Correlates of illness worry in chronic fatigue syndrome. Journal of Psychosomatic Research, 54(4):331-7.

Items of the Illness Worry Scale (IWS)

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

1. Do you think you are more liable to illness than other people?
2. Do you get the feeling people are not taking your illness seriously enough?
3. Do you think you worry about your health more than most people?
4. If the doctor told you that he could find nothing wrong with you would you believe him?
5. If a disease is brought to your attention (through the radio, television, newspapers or someone you know) do you worry about getting it yourself?
6. Do you think there is something seriously wrong with your body?
7. Do you often worry about the possibility that you have got a serious illness?
8. Are you more sensitive to pain than other people?
9. Are you upset by the way people take your illness?
10. Do you get sick easily?
11. Do you often think you might suddenly fall ill?
12. Is it hard for you to believe the doctor when he tells you there is nothing for you to worry about?

Response Format: Yes, No.