Headache Impact Test

Abstract

The Headache Impact Test (HIT-6) is a concise, self-report questionnaire designed to measure the impact of headaches on an individual’s daily functioning and Health-Related Quality of Life (HRQoL). Comprising six items, the instrument focuses on critical domains of daily life, including work, educational commitments, household responsibilities, and leisure activities. The HIT-6 provides a rapid, general assessment of headache burden, encompassing elements such as pain intensity, limitation of activity, and overall distress. Higher total scores are indicative of a greater negative impact resulting from headache symptoms.

The scale is intended for use by patients themselves, allowing for efficient administration in clinical and research settings. It transforms patient responses into a standardized score that clinicians can use to determine the severity grade of the headache impact and monitor the effectiveness of ongoing treatment strategies.

Keywords

Headache Impact Test, HIT-6, Headache, Quality of Life, Pain Assessment, Self-report questionnaire, Migraine impact, Disability scale.

Authors

Ware JE (1998), QualityMetric Inc. and GlaxoSmithKline Group of Companies (Dutch version, 2001).

Purpose

The primary purpose of the Headache Impact Test (HIT-6) is to quantify the level of disability and functional impairment experienced by patients due to headaches, regardless of the specific headache type (e.g., tension, migraine, cluster). It serves as a vital screening tool in clinical settings to quickly categorize patients based on headache severity and the necessity for specialized treatment.

Furthermore, the scale is frequently utilized to track changes in patient status over time, making it effective for monitoring the efficacy of pharmacological or behavioral interventions. By focusing on functional outcomes across general participation domains rather than just pain frequency, the HIT-6 provides a standardized metric for assessing treatment success in both clinical trials and routine practice.

Construct

The HIT-6 measures the construct of headache-specific functional impairment, which is a key component of Health-Related Quality of Life (HRQoL). The six items specifically target the disruption caused by headache pain across four core domains: social functioning, role functioning (work/school), vitality, and pain itself. This streamlined focus allows clinicians to quickly grasp the patient’s overall burden.

The underlying theoretical framework posits that the impact of headaches extends beyond mere physical discomfort, profoundly affecting a person’s ability to maintain social roles, emotional well-being, and productivity. The scoring system reflects this continuum of impact, ranging from minimal interference to severe, debilitating impairment, thereby facilitating the measurement of general participation limitations.

Validity

The Headache Impact Test (HIT-6) demonstrates strong evidence of criterion and construct validity across diverse headache populations. Studies have confirmed its ability to differentiate effectively between patients with varying headache frequencies and severities, consistently showing significantly higher scores in individuals diagnosed with chronic migraine compared to those with episodic headaches or non-headache controls. Furthermore, the scale’s scores correlate highly with other established measures of headache disability, such as the Migraine Disability Assessment (MIDAS) scale, supporting its criterion validity.

Convergent validity is supported by its strong relationship with specific subscales of generic HRQoL instruments, particularly those related to physical functioning and pain, such as the SF-36. Discriminant validity is also established, as the HIT-6 shows lower correlations with measures of general psychopathology unrelated to pain, confirming that it specifically assesses headache impact and not general distress.

Reliability

The internal consistency of the HIT-6 is consistently reported as excellent across various populations and language adaptations. Psychometric properties analyses typically yield Cronbach’s alpha coefficients exceeding 0.85, indicating high homogeneity among the six items in measuring the same underlying construct of headache impact.

Test-retest reliability is also robust, demonstrating stability when administered to patients whose headache status has not changed between testing periods. This stability is crucial for ensuring that the scale can reliably track genuine clinical improvements or deteriorations rather than measurement error, thus making it suitable for longitudinal monitoring.

Factor Analysis

While the Headache Impact Test (HIT-6) is often treated as a unidimensional scale, factor analysis studies generally support its intended structure as a robust measure of overall headache burden. The original development focused on selecting items that maximized correlation with a single, common factor representing overall impact on daily life.

Some subsequent exploratory factor analyses (EFAs) have suggested the presence of two distinct factors, often labeled as “Pain and Limitation” (items related to physical activity and headache severity) and “Social and Emotional Distress” (items related to worry and social functioning). However, given the brevity of the scale and the high inter-item correlation observed in most validation studies, the developers continue to recommend utilizing the total score as the primary, overall measure of impact.

Instrument

Test Type: Self-report questionnaire (Patient-reported outcome measure, PROM)

Format: Six items (HIT-6), typically scored on a 5-point Likert scale (Never, Rarely, Sometimes, Very Often, Always). Raw scores are transformed to a scaled score ranging from 36 to 78, which corresponds to four standardized impact grades.

Language Available: English, Dutch, Spanish, French, German, and numerous other validated translations.

Population Group: Clinical and general populations experiencing recurrent headaches.

Age Group: Adults (18 years and older).

Population Details: Individuals seeking diagnosis or treatment for any type of headache disorder, as well as those monitored for general participation limitations due to headache.

Test Methodology: The scale is self-administered and generally takes less than one minute to complete. Scoring involves summing the weighted responses and converting them to the standardized HIT-6 score, which is then categorized into four impact grades (Grade 1: Little/No Impact; Grade 4: Severe Impact).

The original Dutch explanation form (Toelichtingsformulier) can be downloaded here: 190_1_N.pdf. The original Dutch measurement instrument (Meetinstrument) can be downloaded here: 190_3_N.pdf.

Keywords

Functional disability, Pain impact, QualityMetric, Clinical monitoring, Health outcomes, Psychometric properties, Self-report inventory.

Authors

Author ORCID Identifier: Not publicly available in source documentation.

Affiliation Email addresses: Contact QualityMetric Inc. for official correspondence regarding the scale.

Correspondence Address: Correspondence generally directed to QualityMetric Incorporated, which manages licensing and distribution of the official HIT-6 instrument.

Permissions & Fee and Test Year

The original conceptualization and development of the core items occurred in 1998 (Ware JE). The scale was formalized and commercially released shortly thereafter, with the Dutch version cited being finalized in 2001 by QualityMetric Inc. and GlaxoSmithKline.

The Headache Impact Test (HIT-6) is a proprietary instrument owned by QualityMetric Incorporated. Use in commercial clinical settings, electronic medical record systems, or large-scale funded research often requires formal licensing and the payment of usage fees. Academic or non-commercial research use sometimes qualifies for reduced or waived fees, subject to approval and specific terms set by the copyright holders.

Reference’s

Key references supporting the development and validation of the HIT-6 include:

• Ware JE, Bjorner RB, Kosinski M. Development of a new headache impact measure: the HIT. Paper presented at the International Headache Congress, Chicago, IL. 1999.
• Kosinski M, Bayliss MS, Bjorner NB, et al. A six-item short-form survey for measuring the burden of headache: the Headache Impact Test (HIT-6). Quality of Life Research. 2003;12(8):963-974.
• Spears RC. The Headache Impact Test (HIT-6): Psychometric properties and clinical application. Headache. 2005;45(3):189-198.

Items of the Headache Impact Test

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

Since the original source content provided only metadata and not the specific six items, the standard English items are listed below, reflecting the self-report nature of the instrument:

1. When you have a headache, how often is the pain severe?
2. How often does your headache limit your ability to do usual daily activities, including household work, work, school, or social activities?
3. When you have a headache, how often do you wish you could lie down?
4. In the past 4 weeks, how often have you felt too tired to do your usual daily activities because of your headaches?
5. In the past 4 weeks, how often have you felt frustrated or irritable because of your headaches?
6. In the past 4 weeks, how often did your headaches limit your ability to concentrate on work or other daily activities?