An international study to assess reliability of the Migraine Disability Assessment (MIDAS) score

MIDAS (Migraine Disability Assessment): a valuable tool for work-site identification of migraine in workers in Brazil

CONTEXT

MIDAS was developed as a fast and efficient method for identification of migraine in need of medical evaluation and treatment. It was necessary to translate MIDAS, originally written in English, so as to apply it in Brazil and make it usable by individuals from a variety of social-economic-cultural backgrounds.

OBJECTIVE

To translate and to apply MIDAS in Brazil.

SETTING

Assessment of a sample of workers regularly employed by an oil refinery.

SETTING

Refinaria Presidente Bernardes, Cubatão, São Paulo, Brazil.

PARTICIPANTS

404 workers of the company who correctly answered a questionnaire for the identification and evaluation of headache. When the individual considered it to be pertinent to his own needs, there was the option to answer MIDAS as well.

METHODS

MIDAS, originally written in English, was translated into Brazilian Portuguese by a neurologist and by a translator specializing in medical texts. The final version of the translation was obtained when, for ten patients to whom it was applied, the text seemed clear and the results were consistent over three sessions.

MAIN MEASUREMENTS

Prevalence and types of primary headaches, evaluation of MIDAS as a tool for identification of more severe cases.

RESULTS

From the total of 419 questionnaires given to the employees, 404 were returned correctly completed. From these, 160 persons were identified as presenting headaches, 44 of whom considered it worthwhile answering MIDAS. Nine of these individuals who answered MIDAS were identified as severe cases of migraine due to disability caused by the condition. An interview on a later date confirmed these results. Three were cases of chronic daily headache (transformed migraine) and six were cases of migraine.

CONCLUSIONS

MIDAS translated to Brazilian Portuguese was a useful tool for identifying severe cases of migraine and of transformed migraine in a working environment. The workers did not consider MIDAS to be difficult to answer. Their high level of voluntary participation demonstrates that this medical condition was of real interest among the workers, whether they were sufferers or not.

Evaluating migraine disability: the headache impact test instrument in context

Migraine impairs physical, social and emotional functioning but the diagnosis is not always made despite the availability of helpful tools. Poor patient-physician communication is one reason cited for this. It is arguable that if the impact that headaches are having on a person's life can be communicated adequately to the physician, the likelihood of appropriate management will increase. The tools currently employed for assessing headache impact are reviewed briefly and the Headache Impact Test (HIT) and HIT-6 described as validated and reliable measures of the effect that headaches are having on patients. The availability of the standard test on the internet, with feedback provided, indicates that this is a potentially useful tool enabling headache sufferers to realize the extent of the burden of migraine and empowering them to seek appropriate management strategies.

Cost-effectiveness analysis of stratified versus stepped care strategies for acute treatment of migraine: The Disability in Strategies for Care (DISC) Study

BACKGROUND

The Disability in Strategies for Care (DISC) study was the first large randomised controlled trial to compare alternative treatment strategies in the acute treatment of migraine. With 835 patients in its intention-to-treat efficacy analysis, DISC compared a stratified care strategy, where initial therapy was based on clinical need as determined by the Migraine Disability Assessment Scale (MIDAS) and two stepped care strategies (across attacks and within attacks), where first-line therapy with a simple combination analgesic was escalated, if response had been inadequate, to zolmitriptan, a migraine-specific therapy.

OBJECTIVE

To report on the cost effectiveness of these three strategies from a societal perspective.

STUDY DESIGN AND METHODS

A cost-effectiveness analysis was undertaken using data from the DISC study, and including both health service and productivity costs. Data were collected prospectively on drug usage (main therapy and rescue medication); resource use associated with adverse events was estimated by a clinician blinded to treatment strategy. Health service resource use was costed using UK unit costs (1999 to 2000 values). Data were collected using diary cards on the amount of time patients lost from work, and on reduced effectiveness at work, due to a migraine attack. This facilitated an estimate of the productivity costs associated with the treatment strategies. To assess cost effectiveness, the differences in costs between the strategies were related to the two primary outcome measures in the trial: headache response 2 hours after initial therapy and disability-adjusted time during the first 4 hours after initial therapy.

RESULTS

Although the mean health service cost was higher in the stratified care group (mean over 6 attacks of pound 28.25 versus pound 11.74 and pound 23.15 in the stepped care across attacks group and within attacks group, respectively), mean productivity costs over 6 attacks were lower in the stratified group (pound 112.22 versus pound 144.70 and pound 127.53). The total mean cost over six attacks was, therefore, lowest in the stratified care group (pound 138.95 compared with pound 157.19 in the stepped care across attacks group and pound 148.53 in the stepped care within attacks group), although these differences did not reach statistical significance. In terms of headache response, stratified care was statistically significantly more effective than both forms of stepped care. Using disability-adjusted time, stratified care was statistically significantly more effective than stepped care across attacks, but not against stepped care within attacks.

CONCLUSION

Given its lower mean costs and higher mean effectiveness, a stratified care strategy, which included zolmitriptan, was the dominant strategy and was unequivocally more cost effective from a societal perspective than either stepped care strategy. When the uncertainty around these means was considered, stratified care had the highest probability of being cost effective.

The Migraine Disability Assessment (MIDAS) questionnaire: translation and reliability of the Italian version

We have developed and tested an Italian version of the Migraine Disability Assessment (MIDAS) questionnaire, an established instrument for assessing headache-related disability. A multistep process was used to translate and adapt the questionnaire into Italian, which was then tested on 109 Italian migraine without aura patients, 86 (78.9%) of whom completed the form a second time 21 days later. Overall MIDAS score had good test-retest reliability (Spearman's correlation 0.77), closely similar to that found in English-speaking migraineurs, and individual responses were also satisfactorily reliable. Internal consistency was good (Cronbach's alpha 0.7). These findings support the use of the MIDAS questionnaire as a clinical and research tool with Italian patients.

Prevalence and burden of migraine in the United States: data from the American Migraine Study II

OBJECTIVE

To describe the prevalence, sociodemographic profile, and the burden of migraine in the United States in 1999 and to compare results with the original American Migraine Study, a 1989 population-based study employing identical methods.

METHODS

A validated, self-administered questionnaire was mailed to a sample of 20 000 households in the United States. Each household member with severe headache was asked to respond to questions about symptoms, frequency, and severity of headaches and about headache-related disability. Diagnostic criteria for migraine were based on those of the International Headache Society. This report is restricted to individuals 12 years and older.

RESULTS

Of the 43 527 age-eligible individuals, 29 727 responded to the questionnaire for a 68.3% response rate. The prevalence of migraine was 18.2% among females and 6.5% among males. Approximately 23% of households contained at least one member suffering from migraine. Migraine prevalence was higher in whites than in blacks and was inversely related to household income. Prevalence increased from aged 12 years to about aged 40 years and declined thereafter in both sexes. Fifty-three percent of respondents reported that their severe headaches caused substantial impairment in activities or required bed rest. Approximately 31% missed at least 1 day of work or school in the previous 3 months because of migraine; 51% reported that work or school productivity was reduced by at least 50%.

CONCLUSIONS

Two methodologically identical national surveys in the United States conducted 10 years apart show that the prevalence and distribution of migraine have remained stable over the last decade. Migraine-associated disability remains substantial and pervasive. The number of migraineurs has increased from 23.6 million in 1989 to 27.9 million in 1999 commensurate with the growth of the population. Migraine is an important target for public health interventions because it is highly prevalent and disabling.

How to pick optimal acute treatment for migraine headache

Drug selection for the acute treatment of migraine is based on comorbid disorders, coexistent diseases, and the patient's pain profile and specific needs and expectations. Patients should be instructed to tailor their treatment strategy to meet their specific needs by varying their medications according to pain intensity. This will aid in successful headache management, by increasing compliance and decreasing disability and cost.

Information about migraine disability influences physicians' perceptions of illness severity and treatment needs

OBJECTIVE

To assess physician-patient communication about headache-related disability and to evaluate the influence of information about disability on physicians' perceptions of illness severity and the treatment needs of migraineurs.

BACKGROUND

Evidence suggests that migraine is suboptimally treated in clinical practice, partly due to poor communication between physicians and their patients.

METHODS

One hundred five neurologists and primary care physicians with an interest in headache participated in two interactive surveys, one in North America (n=42) and one in Europe (n=63). Each survey focused on the evaluation of four videotaped migraine cases. The first case was evaluated twice, initially after a typical symptom history that centered on diagnosis and then following a fuller history of migraine disability. Additional questions assessed the extent of the collection of migraine disability information in clinical practice.

RESULTS

Physicians reported that they recorded symptoms relating to diagnosis (eg, pain location/intensity, associated symptoms) rather than information on headache-related disability. Only about one third of patients volunteered disability information. When made available to them, physicians rated information on disability as one of the most important factors in assessing treatment needs. In particular, when physicians knew the patient's disability history: (1) the proportion of physicians who rated the patient's illness as "severe" increased by 128% in North America, 27% in Europe; (2) the proportion of physicians who recommended immediate treatment increased by 63% in North America, 37% in Europe; and (3) the proportion of patients recommended for a follow-up visit increased by 15% in North America, 18% in Europe.

CONCLUSIONS

Physicians and patients often fail to discuss headache-related disability during consultation. This information has a powerful influence on physicians' perceptions of illness severity, treatment choice, and the need for follow-up. Tools to improve communication about headache-related disability, such as the Migraine Disability Assessment questionnaire, may favorably improve migraine management.

The cost effectiveness of stratified care in the management of migraine

OBJECTIVE

To examine the cost effectivess of a stratified-care regimen for patients with migraine--in which patients are stratified by severity of illness, and then prescribed differing treatments according to level of severity--compared with a conventional stepped-care approach.

DESIGN AND METHODS

A decision analytic model was constructed to simulate a controlled clinical trial in which patients with migraine receiving primary medical care were randomly assigned to treatment under a stepped-care or a stratified-care regimen. A health service payer perspective was adopted and the time horizon was 1 year. Data inputs were: (i) the frequency and disability of migraine, derived from population-based studies; (ii) disability level-specific treatment response rates for over-the-counter analgesics,aspirin/metoclopramide and zolmitriptan as the representative of high-end therapy obtained from an international consensus opinion enquiry; and (iii) unit costs of healthcare obtained from UK health service sources.

MAIN OUTCOME MEASURES AND RESULTS

The estimated 1-year direct healthcare costs per primary care patient with migraine were pound sterling 156.82 for stepped care and sterling pound 151.57 for stratified care. Estimates of treatment response rates were 40 and 71% for stepped and stratified care, respectively. The cost per successfully treated attack was sterling pound 23.43 for stepped care and sterling pound 12.60 for stratified care. Stratified care remained cost effective when tested in a wide range of one-way sensitivity analyses, and probabilistic sensitivity analysis showed the cost effectiveness of stratified care to be significant at the 3% level. Conditional confidence analysis showed that the level of confidence in the cost effectiveness of stratified care varied positively with the case mix, i.e. in populations where the proportion of moderate and severely disabled patients with migraine was greater than 25%, the cost effectiveness of stratified care remained statistically significant.

CONCLUSION

A stratified-care treatment strategy (including zolmitriptan as the representative of high-end therapy) is a highly cost-effective method of managing migraine in the primary care setting compared with stepped care, delivering improved clinical outcomes at no additional cost.

Zolmitriptan: differences from sumatriptan

Zolmitriptan is a potent 5-HT(1B/1D) agonist whose targets include the peripheral and central components of the trigeminovascular system. It is generally well-tolerated and has dose-dependent efficacy in the treatment of migraine. The 2.5 mg dose is felt to provide the best balance between efficacy and adverse events. In a direct comparative study, the 2 h headache response rate for zolmitriptan 2.5 mg was statistically superior to sumatriptan 25 and 50 mg, although at 3.3% not clinically significant. Two comparative studies have found no difference in adverse event frequency between zolmitriptan and sumatriptan.

Migraine's impact today. Burden of illness, patterns of care

Migraine is a common disorder that causes severe headaches and associated nausea, photophobia, phonophobia, and temporary disability. Though the pain and other symptoms of migraine can be effectively managed, the condition remains underdiagnosed and undertreated. In this article, Drs Lipton, Stewart, Reed, and Diamond consider the scope and distribution of the migraine problem and the current patterns of care in the United States.

Validity of the Migraine Disability Assessment (MIDAS) score in comparison to a diary-based measure in a population sample of migraine sufferers

The Migraine Disability Assessment (MIDAS) questionnaire is a brief, self-administered questionnaire designed to quantify headache-related disability over a 3 month period. The MIDAS score has been shown to have moderately high test-retest reliability in headache sufferers and is correlated with clinical judgment regarding the need for medical care. The aim of the study was to examine the validity of the MIDAS score, and the five items comprising the score, compared to data from a 90 day daily diary used, in part, to record acute disability from headache. In a population-based sample, 144 clinically diagnosed migraine headache sufferers were enrolled in a 90 day diary study and completed the MIDAS questionnaire at the end of the study. The daily diary was used to record detailed information on headache features as well as activity limitations in work, household chores, and non-work activities (social, family and leisure activities). The MIDAS score was the sum of missed work or school days, missed household chores days, missed non-work activity days, and days at work or school plus days of household chores where productivity was reduced by half or more in the last 3 months. Validity was assessed by comparing MIDAS items and the MIDAS score with equivalent measures derived from the diary. The MIDAS items for missed days of work or school (mean 0.96, median 0) and for missed days of household work (mean 3.64, median 2.0) were similar to the corresponding diary-based estimates of missed work or school (mean 1.23, median 0) and of missed household work (mean 3.93, median 2.01). Values for missed days of non-work activities (MIDAS mean 2.6 and median 1 versus diary mean 2.22 and median 0.95) were also similar. Responses to MIDAS questions about number of days where productivity was reduced by half or more in work (mean 3.77, median 2.00) and in household work (mean 3.92, median 2.00) significantly overestimated the corresponding diary-based measures for work (mean 2.94, median 1.06) and household work (mean 2.22, median 0.98). Nonetheless, the overall MIDAS score (mean 14.53, median 9.0) was not significantly different form the reference diary-based measure (mean 13.5, median 8.4). The correlation between the MIDAS summary score and an equivalent diary score was 0.63. The group estimate of the MIDAS score was found to be a valid estimate of a rigorous diary-based measure of disability. The mean and median values for the MIDAS score in a population-based sample of migraine cases were similar to equivalent diary measures. The correlation between the two measures was in the low moderate range, but expected given that two very different methods of data collection were compared.