Medication-overuse headache detoxification reduces headache disability - the Akershus study of chronic headache.

BACKGROUND AND PURPOSE: Medication-overuse headache (MOH) is a chronic headache (≥15 days/month) associated with overuse of acute headache medication. The objective was to investigate headache-related disability before and after self-detoxification from MOH in the general population, as well as possible predictors for successful outcome. METHODS: This was a prospective cohort study. Participants were identified in a cross-sectional epidemiological sample of 30 000 persons aged 30-44 from the general Norwegian population. People with MOH received short information about the possible role of medication overuse in headache chronification. A total of 108 of the 128 participants (84%) were eligible for follow-up 1.5 years later. RESULTS: Using the Migraine Disability Assessment (MIDAS), people with MOH in the general population were heavily disabled (mean MIDAS score 42.1, 95% confidence interval 31.7-52.6) with a majority in the severe disability class. The MIDAS score was significantly reduced at follow-up (P < 0.001) for those with successful self-detoxification. In multivariate analyses, co-occurrence of migraine (P = 0.044) and lower headache frequency at baseline (P = 0.001) increased the odds for successful self-detoxification and reversion to episodic headache. CONCLUSION: Medication-overuse headache causes substantial disability in the general population. Self-detoxification leads to reduced headache frequency and disability, although 24% of the participants did not complete self-detoxification. Detoxification should be offered to MOH patients as early as possible with a focus on headache frequency, disability and psychological distress.

Lasting improvement of medication-overuse headache after brief intervention - a long-term follow-up in primary care.

BACKGROUND AND PURPOSE: Withdrawal therapy improves the headache situation for many patients with medication-overuse headache (MOH), but relapses are common. The objective was to assess the long-term effectiveness of a general practitioner conducted brief intervention (BI) for MOH. METHODS: Sixty MOH patients initially participating in a blinded cluster-randomized controlled trial evaluating BI versus business as usual (BAU) were followed up for 16 months. Follow-up was open after 6 months. Headache and medication days per month were evaluated in three groups: BI early (BI throughout the study, n = 24), BI late (initial BAU, then cross-over to BI, n = 22) and BAU throughout the study (n = 14). RESULTS: Fifty-five of 60 initially included patients completed the follow-up. The mean change over 16 months' observation in the BI early group was a reduction of 8.4 (5.4-11.4) headache and 13.5 (9.6-17.3) medication days per month. The relapse rate into medication overuse was 8.3%. Patients in the BI late group also improved significantly after a BI. BAU showed no significant improvement. CONCLUSIONS: Treatment for MOH in primary care through a BI is a simple intervention with lasting effects and low relapse rate. This approach may be a logical first step in MOH treatment, and referral should generally be reserved for primary care non-responders.

Chiropractic spinal manipulative therapy for migraine: a three-armed, single-blinded, placebo, randomized controlled trial.

BACKGROUND AND PURPOSE: To investigate the efficacy of chiropractic spinal manipulative therapy (CSMT) for migraineurs. METHODS: This was a prospective three-armed, single-blinded, placebo, randomized controlled trial (RCT) of 17 months duration including 104 migraineurs with at least one migraine attack per month. The RCT was conducted at Akershus University Hospital, Oslo, Norway. Active treatment consisted of CSMT, whereas placebo was a sham push manoeuvre of the lateral edge of the scapula and/or the gluteal region. The control group continued their usual pharmacological management. The RCT consisted of a 1-month run-in, 3 months intervention and outcome measures at the end of the intervention and at 3, 6 and 12 months follow-up. The primary end-point was the number of migraine days per month, whereas secondary end-points were migraine duration, migraine intensity and headache index, and medicine consumption. RESULTS: Migraine days were significantly reduced within all three groups from baseline to post-treatment (P < 0.001). The effect continued in the CSMT and placebo group at all follow-up time points, whereas the control group returned to baseline. The reduction in migraine days was not significantly different between the groups (P > 0.025 for interaction). Migraine duration and headache index were reduced significantly more in the CSMT than the control group towards the end of follow-up (P = 0.02 and P = 0.04 for interaction, respectively). Adverse events were few, mild and transient. Blinding was strongly sustained throughout the RCT. CONCLUSIONS: It is possible to conduct a manual-therapy RCT with concealed placebo. The effect of CSMT observed in our study is probably due to a placebo response.

Predictors of successful primary care detoxification treatment for medication-overuse headache.

OBJECTIVES: To investigate predictors for successful treatment outcome after a brief intervention (BI) for medication-overuse headache (MOH). MATERIALS AND METHODS: This study evaluated predictors of successful withdrawal among patients initially participating in a pragmatic cluster-randomized controlled trial with single crossover in Norwegian general practice (the BIMOH study). BI (early or after crossover) was compared to business as usual (BAU) for the treatment of MOH. Patients were followed up 3 months after the BI. RESULTS: In total, 46 patients had the chance to receive the BI (24 early and 22 after crossover) and were included in the predictor analyses. The mean reduction in headache and medication days/month from baseline for the BI was 6.9 (95% CI: 4.8-9.1) and 10.9 (8.1-13.6). The mean percentage reduction in headache and medication days was 30.5% (21.4-39.7) and 50.4% (39.5-61.3). Only five patients started prophylactic medication. Neither age, gender, co-occurrence of migraine, main type of overused drug at baseline nor Severity of Dependence Scale score at baseline predicted successful withdrawal in the prespecified analyses. Headache days/month and medication use at baseline were significant predictors in exploratory analyses with more headache and medication days predicting worse outcome. CONCLUSIONS: Brief intervention for MOH is a simple and effective intervention in primary care. As the only identified predictors were frequency of headache and medication use, we conclude that treatment for all MOH patients should be attempted in primary care before referral. A raised awareness of MOH is important, as the condition is highly preventable and treatable. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT01314768.

Disability, anxiety and depression in patients with medication-overuse headache in primary care - the BIMOH study.

BACKGROUND AND PURPOSE: Medication-overuse headache (MOH) is common in the general population. Detoxification is the general treatment principle for MOH. The present paper is based on a study of a brief intervention (BI) for MOH in primary care. New data on headache disability and the Hospital Anxiety and Depression Scale (HADS) for MOH patients compared to population controls with and without chronic headache are presented and compared to previously published main outcome data. METHODS: This was a double-blind pragmatic cluster randomized controlled trial carried out amongst 50 general practitioners in Norway. The BI was compared to business as usual (BAU) and population controls, and patients were followed up after 3 months. Primary outcomes were headache and medication days per month after 3 months. Headache disability and HADS were also measured as secondary outcomes. RESULTS: Sixty MOH patients and 40 population controls were included. BI was significantly better than BAU after 3 months regarding primary outcomes. Non-intervention population controls did not change. The MOH patients had significantly higher headache disability and anxiety scores than the population controls. CONCLUSIONS: Patients with MOH are a highly disabled group where anxiety and depression are important comorbidities. Detoxification of MOH by a BI in primary care is effective and has potential for saving resources for more treatment-resistant cases in neurologist care.

Variants in the genes DCTN2, DNAH10, LRIG3, and MYO1A are associated with intermediate Charcot-Marie-Tooth disease in a Norwegian family.

INTRODUCTION: Charcot-Marie-Tooth disease (CMT) is a heterogeneous inherited neuropathy. The number of known CMT genes is rapidly increasing mainly due to next-generation sequencing technology, at present more than 70 CMT-associated genes are known. We investigated whether variants in the DCTN2 could cause CMT. MATERIAL AND METHODS: Fifty-nine Norwegian CMT families from the general population with unknown genotype were tested by targeted next-generation sequencing (NGS) for variants in DCTN2 along with 32 CMT genes and 19 other genes causing other inherited neuropathies or neuronopathies, due to phenotypic overlap. In the family with the DCTN2 variant, exome sequencing was then carried out on all available eight family members to rule out the presence of more potential variants. RESULTS: Targeted NGS identified in one family a variant of DCTN2, c.337C>T, segregating with the phenotype in five affected members, while it was not present in the three unaffected members. The DCTN2 variant c.337C>T; p.(His113Tyr) was neither found in in-house controls nor in SNP databases. Exome sequencing revealed a singular heterozygous shared haplotype containing four genes, DCTN2, DNAH10, LRIG3, and MYO1A, with novel sequence variants. The haplotype was shared by all the affected members, while the unaffected members did not have it. CONCLUSIONS: This is the first time a haplotype on chromosome 12 containing sequence variants in the genes DCTN2, DNAH10, LRIG3, and MYO1A has been linked to an inherited neuropathy in humans.

Net carbon flux of dead wood in forests of the Eastern US.

Downed dead wood (DDW) in forest ecosystems is a C pool whose net flux is governed by a complex of natural and anthropogenic processes and is critical to the management of the entire forest C pool. As empirical examination of DDW C net flux has rarely been conducted across large scales, the goal of this study was to use a remeasured inventory of DDW C and ancillary forest attributes to assess C net flux across forests of the Eastern US. Stocks associated with large fine woody debris (diameter 2.6-7.6 cm) decreased over time (-0.11 Mg ha(-1) year(-1)), while stocks of larger-sized coarse DDW increased (0.02 Mg ha(-1) year(-1)). Stocks of total DDW C decreased (-0.14 Mg ha(-1) year(-1)), while standing dead and live tree stocks both increased, 0.01 and 0.44 Mg ha(-1) year(-1), respectively. The spatial distribution of DDW C stock change was highly heterogeneous with random forests model results indicating that management history, live tree stocking, natural disturbance, and growing degree days only partially explain stock change. Natural disturbances drove substantial C transfers from the live tree pool (≈-4 Mg ha(-1) year(-1)) to the standing dead tree pool (≈3 Mg ha(-1) year(-1)) with only a minimal increase in DDW C stocks (≈1 Mg ha(-1) year(-1)) in lower decay classes, suggesting a delayed transfer of C to the DDW pool. The assessment and management of DDW C flux is complicated by the diversity of natural and anthropogenic forces that drive their dynamics with the scale and timing of flux among forest C pools remaining a large knowledge gap.

Aortic root pathology in Marfan syndrome increases the risk of migraine with aura.

AIM: To assess the lifetime prevalence of migraine in patients with Marfan syndrome (MFS) and to investigate a history of aortic root replacement (AR) as a possible risk factor. METHODS: In a multicentre study 123 MFS patients (n = 52 with AR, n = 71 without AR), 82 age- and sex-matched controls and 51 patients with AR but without MFS, were interviewed using a semi-structured headache questionnaire. A multinomial logistic regression model was used to investigate risk factors for migraine with and without aura, adjusting for age and gender. RESULTS: Lifetime migraine prevalence was increased in female MFS patients (51%) compared to healthy female controls (29%), p = 0.017. In males lifetime migraine prevalence among MFS patients was only numerically increased. Lifetime prevalence of migraine with aura was increased among MFS patients compared to healthy controls both in males (19% vs. 3%, p = 0.048) and females (30% vs. 14%, p = 0.049). A history of AR, independently from MFS, gender and age, increased the lifetime prevalence of migraine with aura (OR 3.1 [1.2-8.0]). In all but one patient migraine started before the AR. CONCLUSIONS: The lifetime prevalence of migraine with aura, but not migraine without aura, is increased in patients with MFS. This association is driven by a history of AR. The replacement procedure itself is unlikely to be causally associated with migraine as in nearly all subjects, migraine started before the procedure. However this study adds to the evidence that underlying vessel wall pathology may be involved in migraine with aura.

An adapted Severity of Dependence Scale is valid for the detection of medication overuse: the Akershus study of chronic headache.

BACKGROUND AND OBJECTIVE: Medication overuse headache is a common subtype of chronic headache involving the overuse of simple analgesics, opioids, ergotamine or triptans or combinations of these medications. Medication overuse may worsen the headache and has been described to have many characteristics similar to addiction. The purpose of this study was to validate and optimize the Severity of Dependence Scale (SDS) for use amongst people with chronic headache. DESIGN/SETTING: In a cross-sectional epidemiological survey, an age- and gender-stratified sample of 30,000 30- to 44-year-old people were recruited via a posted questionnaire. Those with self-reported chronic headache were interviewed by neurological residents at Akershus University Hospital, Oslo. Headache was classified according to the International Classification of Headache Disorders. Split file methodology was employed for data analysis. MAIN OUTCOME MEASURE: Severity of Dependence Scale score in those with and without medication overuse. RESULTS: Severity of Dependence Scale score was a significant predictor of medication overuse amongst chronic headache patients. Medication overuse could be predicted with sensitivity, specificity, positive and negative predictive values of 0.79, 0.84, 0.84 and 0.79, respectively, in men and 0.76, 0.77, 0.73 and 0.79 in women. Linear regression and factor analysis suggested a redundancy for the SDS question 'Do you think your use of your headache medication was out of control?' Removal of this question improved Chronbach's alpha=0.76. CONCLUSION: The SDS is valid for detecting medication overuse and dependency like behaviour amongst people with chronic headache. The adapted version may be used to identify chronic headache patients who may benefit from detoxification.

Reduction in medication-overuse headache after short information. The Akershus study of chronic headache.

OBJECTIVE: our aim was to investigate the course of medication-overuse headache in the general population and the effect of simple advice regarding medication overuse. DESIGN: prospective cohort study. Participants were identified in a cross-sectional epidemiological sample of 30000 persons aged 30-44 from the general Norwegian population. People with chronic headache (≥ 15 days per month for at least 3 months) and medication overuse received short information about the possible role of medication overuse in headache chronification. A cohort was followed up 1½ years later. The diagnostic criteria of the International Classification of Headache Disorders and data splitting methodology were used. SETTING: Akershus University Hospital, Oslo, Norway. PARTICIPANTS: a total of 109 participants with chronic primary headache and medication overuse were available for follow-up (85% participation rate). MAIN OUTCOME MEASURE: Change in medication days and headache days per month. RESULTS: at baseline chronic tension-type headache was found in 92% of participants; 8% had chronic migraine or new daily persistent headache. Migraine co-occurrence was found in 53%. The mean duration of chronic headaches were 8-18 years, the mean duration of medication overuse between 5 and 10 years prior to intervention. At follow up, the mean medication days were significantly reduced from 22 days to 6 days per month, and 76% no longer had medication overuse. Forty-two percent no longer had chronic headache and the headache index was reduced by 24%. CONCLUSION: our examination and short information served as a modified brief intervention which can improve chronic headache and medication overuse in the general population.

Genetic epidemiology of Charcot-Marie-Tooth in the general population.

BACKGROUND AND PURPOSE: the frequency of different Charcot-Marie-Tooth (CMT) genotypes has been estimated in clinic populations, but prevalence data from the general population are lacking. METHODS: our population-based genetic epidemiological survey included persons with CMT residing in eastern Akershus County, Norway. The participants were interviewed and examined by one geneticist/neurologist and classified clinically, neurophysiologically and genetically. RESULTS: two hundred and forty-five persons from 116 families had CMT. This corresponds to 1 per 1214 persons (95% CI 1062-1366) have CMT in the general population. CMT1 (motor conduction velocity (MCV) <38 m/s), CMT2 (MCV >38 m/s) and CMT intermediate (MCV 25-45 m/s) were found in 48.2%, 49.4% and 2.4% of the families. A total of 27.2% of the families and 28.6% of the affected had a mutation in the investigated CMT genes. The prevalence of the peripheral myelin protein 22 (PMP22) duplication and point mutation in the connexin32 (Cx32), myelin protein zero (MPZ) and mitofusin2 (MFN2) genes was found in 13.6%, 6.2%, 1.2%, 6.2% of the families, and in 19.6%, 4.8%, 1.1%, 3.2% of the affected, respectively. None of the families had point mutations in the early growth response 2 (EGR2), PMP22 or small integral membrane protein of lysosome/late endosome (SIMPLE) genes. CONCLUSIONS: CMT is the most common inherited neuropathy. At present, 43 CMT genes are known, and an examination of all known genes would probably only identify mutations in approximately 50% of those with CMT. Thus, it is probable that at least 30-50 CMT genes are yet to be identified.

Personality traits and psychological distress in persons with chronic tension-type headache. The Akershus study of chronic headache.

OBJECTIVES: To explore the relationship between chronic tension-type headache (CTTH) and psychological factors (personality traits and psychological distress) in a population-based sample and to determine the influence of headache frequency and medication days. METHODS: An age- and sex-stratified random sample of 30,000 persons aged 30-44 years from the general population received a mailed questionnaire. Those with a self-reported chronic headache were interviewed by neurological residents. The questionnaire response rate was 71%, and the rate of participation in the interview was 74%. The International Classification of Headache Disorders was used. Personality traits were assessed by the Eysenck Personality Questionnaire (EPQ), neuroticism and lie scale, and level of psychological distress, by the Hopkins Symptom Checklist-25 (HSCL-25). For comparison, cross-sectional data from the Danish and the Norwegian general population using the same instruments were used. RESULTS: Persons with CTTH had a significantly higher neuroticism score and a significantly higher level of psychological distress than the general population. Headache- or medication days per month had no significant influence on the neuroticism- and lie scores or the HSCL-25 score. CONCLUSIONS: Persons with CTTH have a high level of neuroticism and psychological distress. This can be either a primary or a secondary effect related to the premorbid psyche or caused by the chronic pain and is a question that future studies should address.

Chronic rhinosinusitis gives a ninefold increased risk of chronic headache. The Akershus study of chronic headache.

We studied the association of chronic headache and chronic rhinosinusitis in 30,000 persons aged 30-44 years from the general population. They received a mailed questionnaire. Those with possible chronic headache were interviewed by neurological residents. The criteria of the American Academy of Otolaryngology--Head and Neck Surgery were applied to diagnose headache attributed to chronic rhinosinusitis (HACRS), otherwise the International Classification of Headache Disorders was used. The questionnaire response rate was 71%, and the participation rate of the interview was 74%. Compared with the general population, persons with chronic rhinosinusitis have an at least ninefold increased risk of having chronic headache. A 3-year follow-up showed that HACRS symptoms were significantly improved after treatment with nasal surgery, nasal corticosteroids, discontinuation of overused headache medications and discontinuation of nasal decongestants or unspecified reasons. Chronic rhinosinusitis is significantly associated with chronic headache, and HACRS is likely to be a distinct type of headache.

Secondary chronic cluster headache due to trigeminal nerve root compression.

A 50-year-old woman had a gradual onset of chronic headache located in the right temporal region and a burning sensation in the root of the tongue which over a year evolved into chronic cluster headache with a milder chronic headache in-between the severe cluster headache attacks. A cerebral magnetic resonance imaging (MRI) showed vascular compression of the trigeminal nerve root on the pain side. Neurosurgery microvascular decompression relieved the patient's chronic cluster headache, the chronic intermittent headache and the burning tongue sensation. The effect was persistent at a 1 year follow-up. Patients with atypical symptoms of cluster headache should be examined with cerebral MRI angiography of arteries and veins to exclude symptomatic causes.

The Severity of Dependence Scale detects people with medication overuse: the Akershus study of chronic headache.

OBJECTIVE: To evaluate the Severity of Dependence Scale (SDS) in people with primary chronic headache and analyse the pattern of medication overuse. DESIGN: Cross sectional epidemiological survey. A posted questionnaire screened for chronic headache. Neurological residents interviewed those with self-reported chronic headache. The International Classification of Headache Disorders was used. Split file methodology was employed for data analysis. SETTING: Akershus University Hospital, Oslo, Norway. PARTICIPANTS: A random sample of 30,000 people, aged 30-44 years, from the general population of Akershus County, Norway. 405 people had primary chronic headache. MAIN OUTCOME MEASURE: SDS score in those with and without medication overuse. RESULTS: The screening questionnaire response rate was 71% and the participation rate of the interview 74%. Among 405 people with primary chronic headache, 95% had chronic tension-type headache, 4% had chronic migraine and <1% had other primary chronic headaches. Of 386 persons with chronic tension-type headache, 44% had medication overuse and 47% had co-occurrence of migraine. Simple analgesics, combination analgesics, triptans, ergotamine, opioids and a combination of acute medications were overused by 65%, 27%, 4%, <1%, 1% and 2% of people, respectively. The mean SDS score was significantly higher in those with than in those without medication overuse (5.6 vs 2.7; p<0.001). CONCLUSION: The SDS questionnaire detects medication overuse and dependency-like behaviour in persons with primary chronic headache.

Prevalence of new daily persistent headache in the general population. The Akershus study of chronic headache.

The aim of the present study was to investigate the prevalence of new daily persistent headache (NDPH) in the general population, and compare the clinical characteristics of NDPH and chronic tension-type headache (CTTH). This is a population-based cross-sectional study. A random sample of 30 000 persons aged 30-44 years was drawn from the population of Akershus County, Norway. A postal questionnaire was screened for chronic headache. Those (n = 633) with self-reported chronic headache within the last month and/or year were invited to an interview and examination by a neurological resident. A follow-up interview was conducted after 1.5-3 years. The headaches were diagnosed according to the International Classification of Headache Disorders, 2nd edn and relevant revisions. The response rate of the questionnaire was 71% and the participation rate of the interview was 74%. Four persons, three men and one woman, had NDPH. The overall 1-year prevalence of NDPH was 0.03%. The clinical characteristics of NDPH and CTTH were similar, except for the sudden onset in DPH.Three of the four persons with NDPH had medication overuse. Follow-up disclosed that the symptomatology of NDPH is not unchangeable, since two persons had improvement of their NDPH. NDPH is rare and occurs in one of 3500 persons from the general population of 30-44-year-olds. It is often associated with medication overuse.

Interrelation of chronic tension-type headache with and without medication overuse and migraine in the general population: the Akershus study of chronic headache.

We studied the interrelation of chronic tension-type headache with and without medication overuse (CTTH) and migraine in a random sample of 30 000 persons aged 30-44 years. They received a mailed questionnaire. Those with a possible chronic headache were interviewed by neurological residents. The International Classification of Headache Disorders was used. A total of 386 persons had CTTH. Compared with the general population, men had a 2.8-fold and women a 2.4-fold significantly increased risk of migraine without aura (MO). The risk of migraine with aura (MA) was not increased. The mean age at onset of CTTH was significantly higher in those with than in those without co-occurrence of MO. Bilateral MO attacks were significantly more frequent in those with age at onset of CTTH prior to age at onset of MO compared with those with age at onset in reverse order. CTTH and MO are interrelated, possibly in a complex matter. In contrast, CTTH and MA are not interrelated.

A vertical VAS is a valid instrument for monitoring headache pain intensity.

Visual analogue scales (VAS) are well-validated instruments for assessing pain intensity, but have an impractical format. The aim of the study was to validate a vertical against a horizontal VAS for pain intensity registration. Out-patients with headache or non-headache pain were included. Participants completed a horizontal and a vertical VAS. Both were completed twice for test-retest. Headache was diagnosed according to the International Classification of Headache Disorders, 2nd edition. The results on vertical and horizontal VAS did not differ significantly in the different headache or chronic pain groups. For test-retest evaluation, effect sizes and Cohen's delta values were < 0.029 with < 1.5% change from test to retest (P < 0.01). Correlation coefficients were > 0.95. Bland-Altman analysis showed good agreement between vertical and horizontal scores with correlation coefficients > 0.84. A vertical VAS is equally valid as a horizontal VAS for registration of pain intensity in headache and non-headache patients.

Prevalence of secondary chronic headaches in a population-based sample of 30-44-year-old persons. The Akershus study of chronic headache.

We studied secondary chronic headaches (> or = 15 days/month for at least 3 months) in a random sample of 30 000 persons aged 30-44 years. They received a mailed questionnaire. Those with self-reported chronic headache within the last month and/or year were invited to an interview and examination by a neurological resident. The criteria of the International Classification of Headache Disorders (ICHD-II) were applied. The questionnaire response rate was 71%, and the participation rate of the interview was 74%. Of the 633 participants, 298 had a secondary chronic headache. The 1-year prevalence of secondary chronic headache was 2.14%, i.e. chronic posttraumatic headache 0.21%, chronic headache attributed to whiplash injury 0.17%, post-craniotomy headache 0.02%, medication-overuse headache (MOH) 1.72%, cervicogenic headache 0.17%, headache attributed to chronic rhinosinusitis 0.33% and miscellaneous headaches 0.04%. The majority of those with ICHD-II-defined secondary chronic headache had MOH, while about one-third had other secondary headaches often in combination with MOH.

Which strategy should be applied? Design of a Norwegian epidemiological survey on chronic headache.

BACKGROUND: Large-scale population-based epidemiological surveys on chronic headache based on clinical interview by a physician are lacking. AIMS OF THE STUDY: To describe a method that aims to provide valid information on chronic headache. METHOD: A self-administered questionnaire including two questions about headache frequency within the last month and within the last year was used to screen for possible chronic headache. Respondents with self-reported headache more than half of the days were interviewed by neurological residents with experience in headache diagnostics. DISCUSSION: Previous studies have shown that a single question from a self-administered questionnaire can be used to screen for chronic headache. However, a precise headache diagnosis requires an interview by a physician experienced in headache diagnostics, as diagnoses extracted from questionnaires or provided by lay interviewers are not sufficiently precise. CONCLUSIONS: A combination of a screening questionnaire and a clinical interview by a physician is likely to be a cost-effective method to conduct an epidemiological survey on chronic headache.