Validation of a self-reported instrument to assess work-related difficulties in patients with migraine: the HEADWORK questionnaire

Background: The degree to which work-related difficulties are recognized in headache research is poor and often carried out with inadequate information such as "reduced ability to work as usual", which do not capture at all the variety of difficulties and the factors that impact over them. The aim of this paper is to present the validation of the HEADWORK questionnaire, which addresses the amount and severity of difficulties in work-related tasks and the factors that impact over them.Methods: We developed a set of items based on a previous literature review and patients' focus groups and tested it on a wide set of patients with episodic and chronic migraine attending eight different Italian headache centers. HEADWORK factor structure was assessed with exploratory and confirmatory factor analysis; internal consistency and construct validity were addressed as well.Results: The validation sample (N= 373) was mostly composed of patients with episodic migraine without aura (64.3%) and of females (81%). Factor analysis retrieved two different scales: "Work-related difficulties", composed of eleven items which explain 67.1% of the total variance, and "Factors contributing to work difficulties", composed of six items which explain 52.1% of the total variance. Both HEADWORK subscales have good measurement properties, with higher scores being associated to higher disability, lower quality of life, lower productivity, higher headache frequency and pain intensity.Conclusions: HEADWORK is a 17-item, two-scale questionnaire addressing the impact of migraine on work-related difficulties in terms of difficulties in general or specific skills, and the factors contributing to these difficulties, defined as negative impact on work tasks. It can be used to address disability weights for the purpose of calculating the burden of migraine, and to assess the balance between therapeutic and side effects of medication on productivity

HEADWORK Questionnaire: Why Do We Need a New Tool to Assess Work-Related Disability in Patients With Migraine?

Objective: This article reviews current headache disability measures and clinical need, as well as presenting the rationale for a new measure addressing work-related disability in migraine patients and the steps devoted to this aim. Background: Episodic and chronic migraine (EM and CM) constitute an enormous economic burden to societies, and the vast majority of this burden is attributable to indirect costs, ie those associated with productivity loss. A measure of work-related disability is therefore needed to quantify the impact of EM and CM on patients' ability to carry out work tasks. Methods: We briefly present the advantages and disadvantages of the disability measures that have been most commonly used for this purpose and the rationale for developing a new measure. Results: The entire process of development of HEADWORK, a questionnaire designed to assess work-related disability, is presented together with short-term sensitivity to change. Conclusions: Current headache disability measures need improvement. HEADWORK is a valid, reliable, and sensitive questionnaire to address the amount and severity of work-related difficulties and of the factors contributing to such difficulties. HEADWORK is suitable for daily clinical practice, epidemiological research and for clinical trials, and potentially to define work-related disability weights for the calculation of migraine indirect costs