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

DOI: https://doi.org/10.1186/s10194- 018- 0914- 7

Abstract-Summary 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 fac- tors that impact over them.

The aim of this paper is to present the validation of the HEADWORK question- naire, which addresses the amount and severity of difficulties in work-related tasks and the factors that impact over them.

HEADWORK factor structure was assessed with exploratory and confirmatory

factor analysis; internal consistency and construct validity were addressed as well. Factor analysis retrieved two different scales: “Work-related difficulties”, com- posed of eleven items which explain 67.1% of the total variance, and “Factors con- tributing to work difficulties”, composed of six items which explain 52.1% of the total variance.

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.

Extended: The aim of this paper is to validate this new questionnaire and report

its measurement properties.

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Future studies are also needed to test the validity of HEADWORK in other head-

ache disorders, such as tension-type headache.

Background Presenteeism is the main driver of migraine cost and burden: in fact, for each lost workday, patients with EM and CM work three to four days with reduced productiv- ity [401, 402], and the cost associated to presenteeism is higher than that associated to absenteeism [13, 403, 404].

Fourteen topics, that could be referred to difficulties with work-related activities, were transformed into MESH terms and were used to search for relevant publica- tions in which these difficulties were experienced by patients with EM, CM, chronic daily headache or MOH.

The main reason for the paucity of information on this topic is, in our opinion, the lack of patient-reported outcome measures (PROMs) specifically aimed to cap- ture the presence, the severity and the type of work-related difficulties in patients with EM and CM.

Given the paucity of literature data, we ran a qualitative study with the aim of exploring which were the most relevant difficulties experienced by patients with their work activities and which were the factors that contributed most to these dif- ficulties, getting indications directly from employed patients with EM and CM.

Methods The questionnaire is composed of 14 items that form three scales, namely role- restriction (RR), role-prevention (RP) and emotional function (EF): each scale has a 0–100 score, with lower scores indicating lower health-related QoL. Items refer to different daily activities or social situations, and patients have to rate how frequently migraine determined an impact on these activities, thinking back to the previous 4 weeks, using a 6-point scale from never to always.

We used Pearson’s correlation, and expected that HEADWORK scales: (a) were directly correlated with all the other variables (with the exclusion of MSQ scores, and with the estimated average productivity, where an inverse correlation is expected), and with correlation coefficients <.700; (b) had a stronger correlation with the WHODAS-12 than with the MSQ scores, as the construct underlining HEADWORK is the amount and severity of difficulties with work-related activities; (c) had a stronger correlation with the average pain severity and the average work ability than with the variables related to frequency of headache, workdays lost and days worked with reduced productivity.

Results The second HEADWORK scale, which we named “Factors contributing to work difficulties”, is composed of six items with a theoretical range 6–30: actually, it ranged between 6 and 29 and its mean was 15.8 (SD 5.0).

HEADWORK scales were more strongly correlated with the WHODAS-12 than with MIDAS and MSQ scores and also with the average pain severity and the

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average work ability rather than with frequency of headache, workdays lost and days worked with reduced productivity.

Consistently with our expectations, females and patients with CM showed higher scores at both HEADWORK scales, than males and EM patients, with medium to large ES.

Contrary to our expectations, people working less than 40 h per week showed higher scores than those working less only at HEADWORK “Factors contributing to work difficulties” scale, with a small ES, while no differences were found for the subscale “Work-related difficulties”.

Discussion Our results showed that the different dimensions regarding the negative influence of migraine on work activities, i.e. the amount and severity of difficulties in work- related tasks and the factors that impact over them, can be measured by two dis- tinct scales.

It will be very interesting to understand what may be the main drivers of HEADWORK scales change, considering the potential role of different variables, such as frequency (which is generally considered as the major outcome measure in headache research—but showed a modest correlation with HEADWORK scores), or severity of headaches, but also presence of treatment-related side effects, particu- larly such those that may have an important role on work-place activities and pro- ductivity, such as somnolence, sedation dizziness or fatigue, and which are relatively common with preventive anti-migraine medications.

Conclusions We presented the validation of the HEADWORK questionnaire, a brief question- naire which addresses the impact of migraine on work-related difficulties in terms of presence, and severity, of difficulties in general and specific skills, and it also addresses the factors contributing to these difficulties, defined as negative impact on work tasks.

We propose HEADWORK as a feasible way to produce reliable work-related disability weights in studies evaluating the burden of episodic and chronic migraine in epidemiological and clinical research.

Future studies are also needed to test the validity of HEADWORK in other head-

ache disorders, such as tension-type headache.

Acknowledgement A machine generated summary based on the work of Raggi, Alberto; Covelli, Venusia; Guastafierro, Erika; Leonardi, Matilde; Scaratti, Chiara; Grazzi, Licia; Bartolini, Marco; Viticchi, Giovanna; Cevoli, Sabina; Pierangeli, Giulia; Tedeschi, Gioacchino; Russo, Antonio; Barbanti, Piero; Aurilia, Cinzia; Lovati, Carlo; Giani, Luca; Frediani, Fabio; Di Fiore, Paola; Bono, Francesco; Rapisarda, Laura; D’Amico, Domenico. 2018 in The Journal of Headache and Pain.

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The relationship between headache-attributed disability and lost productivity: 1. A review of the literature