In 2015 all United Nations Member States adopted the 2030 Agenda for Sustainable Development (ASD-2030) which sets out, through 17 Sustainable Development Goals (SDGs), a path for the prosperity for people and the planet [1]. Specifically, the SDG 3 is aimed to “Ensure healthy lives and promote well-being for all at all ages” and is articulated in a set of targets which are overall aimed to reduce mortality and disease burden.

To pursue the goal of SDG 3, headache disorders should be adequately addressed at a global level, as they are among the most prevalent and disabling conditions: primary headaches constitute approximately 90% of headache cases, and the remaining are secondary. According to the latest estimates of the Global Burden of Disease Study (GBD), in 2019 there were 793.8 million incident cases of primary headaches, 2.60 billion prevalent cases and a total of 46.6 million Years Lived with a Disability (YLD) [2]. In terms of YLD rates, globally, headache disorders rank 3rd after low back pain and depressive disorders; however, amongst persons aged 15–49 they rank 1st, and account for 8% of total YLDs. However, primary headaches are also frequent and disabling in children and adolescents [3]. Globally, and considering all-age populations, tension-type headache (TTH) is the second most prevalent condition, and migraine the second most disabling [2]. Despite the fact that headaches are not associated to fatal outcomes, if these are taken into account (and thus Disability-Adjusted Life Years – DALYs rankings are considered) headache disorders burden is still considerable. In fact, they rank 15th considering all-age group, 2nd considering the population aged 10–24 years (where they account for 5% of the total DALYs) and 5th considering the population aged 25–49 years (where they account for 3.7% of the total DALYs) [2].

Headache disorders are long-lasting conditions, which usually peak in the first adulthood particularly among women [4] thus magnifying gender inequalities. Migraine in particular poses a relevant burden on populations due to its considerable prevalence (around 14%) and substantial impact, with symptoms peaking during the most productive years. TTH, although less disabling, is very frequent, to the point that the majority of the population experiences it in their lifetime [5]. In addition to this, secondary headaches, and particularly those associated with long-COVID syndrome, might further increase the overall prevalence of these non-communicable diseases [6,7,8,9].

Reducing the burden of headaches is a way to ensure healthier lives to approximately one third of the world population. However, considering the heterogeneity in presentation and the variability in frequency, a multiplicity of parameters has to be taken into consideration to ease the overall burden of headache disorders [10].

The aim of this narrative review is to propose a set of actions that can be implemented in order to reduce the burden and disability of headache globally, by proposing a way to rethink how to scale and implement actions using headache as a public health target towards SDG 3 by 2030. The actions herein discussed are not to be intended as practical solutions, but as proposals to set the stage on policy guidelines. The review is organized into six subsections, each addressing the topic of a specific SDG 3 target (see Table 1 for a synopsis):

Table 1  A Synopsis on SDG 3 targets implementation reducing the burden of headache disorders with a synthesis of main policy actions 1.

Reducing the burden of primary headaches by reducing chronification, reducing barriers and impact on daily life in a biopsychosocial perspective (Target 3.4).

2.

Reducing medication overuse in acute management of primary headaches: strategies at primary, secondary, tertiary levels of care in a global perspective (Target 3.5).

3.

Promoting education of health care professionals in the management of primary headaches and defining feasible methodology to support health-care facilities development to deliver comprehensive headache care pathways (Target 3.8).

4.

Defining strategies for access to existing treatments for headaches in low- and middle-income countries and for facilitating the inclusion of these countries in the research and development of new medicines (RCTs or RWS) (Target 3.b).

5.

Defining strategies to develop and implement training and education in low- and middle-income countries to improve the skills of healthcare professionals for management of headaches in primary and secondary care (Target 3.c).

6.

Defining strategies for an inclusive and global alliance against headache disorders among headache healthcare professional working parties to respond to public health unmet needs in headache area (Target 3.d).

What we propose here does take into account any “standard” state of headache care as a starting point for the implementation of policies first and actions then. In fact, the inequalities at the global level are so wide that in the most disadvantaged countries, i.e. low- and middle-income countries (LMIC), the possibility of seeing a healthcare professional with specific expertise on headaches is very low, and headache care is mostly based on anti-inflammatories. Setting the stage for policies, particularly in LMIC, is a priority that clearly comes before concrete actions can be even planned, but it is of outmost importance considering that around 80% with headache disorders are from LMIC [2].

Reducing the burden of primary headaches by reducing chronification, reducing barriers and impact on daily life in a biopsychosocial perspective (Target 3.4)

Primary headache disorders are common and burdensome conditions. Considering all-age groups, TTH is the second most prevalent condition, and migraine the second most disabling. In the age group 15–49, headache disorders rank first accounting for approximately 8% of the total disability [2].

Chronification is the process which leads to an increase in headache frequency above 15 days per month and is associated with more severe disability [11]. The main predictors of chronification, with specific reference to migraine, are: comorbidities, genetic predisposition, psychological and lifestyle factors, and medication overuse [11, 12]. When compared to those with episodic migraine (EM), patients with chronic migraine (CM), high-frequency episodic migraine, and chronic TTH show higher disability and impact, as shown in different recent studies [13,14,15,16,17,18,19], lower treatment satisfaction, and higher treatment needs which are often not adequately met in the clinical practice [17,18,19].

When patients are seen in the healthcare system at a single point in time, measuring headache frequency might not adequately assess the severity of the patient’s condition [16]. In fact, excluding those with lower frequency (e.g. up to 4 days per month) or those with the highest frequency (i.e. daily or close to daily), a snapshot of severity solely based on frequency is only partially informative, as it does not address the impact of the attacks nor whether the patient’s clinical situation is improving or worsening. For example, a frequency of 15 headache days per month might reflect substantial improvement, if the baseline was 25–30 days, or reason for alarm if the baseline was 4–8 days, and fluctuations between EM and CM are in particular very common. As shown by Serrano and colleagues, 7.6% of patients with EM progress to CM, and nearly 75% of those with CM may remit to EM at some point during a 12-month period [20].

A full evaluation of clinical severity, which in turn is relevant to inform how to reduce chronification by addressing barriers and impact on daily life, needs to be based on a biopsychosocial perspective [21] and take into account a multiplicity of parameters [16]. These should at least include longitudinal changes in headache frequency, current headache frequency, headache severity, associated symptoms (e.g. nausea, osmophobia, phono- and photophobia cutaneous allodynia), the presence of aura, TTH-like pain, comorbidities, psychological difficulties, the variability in response to treatment, and the degree to which pain and other symptoms limit the ability of patients to function at their usual level, which can be fruitfully measured using validated instruments addressing headache-related disability, quality of life instruments, or headache impact. Lack of access to appropriate healthcare is a major barrier to good patient outcomes, including lack of access to medical consultation, accurate diagnosis, and the most appropriate pharmacological and non-pharmacological treatments [22]. Lack of access also prevents appropriate diagnosis and management of common comorbidities, including but not limited to psychological comorbidities that are common amongst those with chronic headache and can increase the complexity of the treatment approach [23,24,25].

Unmet medical needs are commonly reported by patients with headache disorders, especially migraine, and are often focused on the lack of adequate therapies [18]: this, however, does not strictly deal with the availability of “a tailored therapy for a patient”. In fact, the armamentarium of medications for acute and preventive headache care is huge, although its availability varies by country, and may be complemented by non-pharmacological treatments. Therefore, the challenge deals with the identification of the best care pathway for each patient, also considering the setting in which they are treated, i.e. treating them at the “appropriate level of care”. The majority of patients with primary headaches may be treated at a primary (nurse or doctor-based, according to setting) or intermediate level of care [26], leaving specialty care for the most complex cases only: the implementation of a model which is based on both clinical severity, patients’ needs, and response to available treatments is expected to be cost-effective and cost-saving in the medium-term [27].

In summary, barriers mostly deal with the organization of healthcare systems, which might hinder the ability to provide the best treatment, but also with “cultural” issues, i.e. physicians often lack training in how to best treat patients. In the latest years, numerous different treatments and approaches have demonstrated their efficacy as preventive treatments for patients with migraine disorders, including pharmacological [28] and non-pharmacological strategies [29]. The current challenge, therefore, deals with delivering the most appropriate evidence-based treatment at the most appropriate level of care for each single patient.

The main policy action to be taken is therefore to develop, at the level of local health systems, a pathway of primary headaches healthcare which is able to identify patients according to their specific clinical severity and needs, e.g. patients with chronic headache with or without medication overuse for whom headache frequency reduction and cessation of medication overuse is the target, as opposed to those with a stable pattern of low-frequency episodic migraine, for whom maintenance of such pattern and avoiding chronification is the target. In the case of migraine, such actions should include:

1.

A definition of clinical severity which accounts not only for frequency-based parameters, but also for the associated migraine symptoms – such as nausea, osmophobia, phonophobia, photophobia, cutaneous allodynia, aura – the quality and intensity of pain, the presence of comorbidities, and the degree to which symptoms’ severity limit patients’ ability to function at their usual level in their daily lives [10];

2.

The appreciation and consideration of recent (i.e. referred to the last 6–12 months) variations in the parameter “headache frequency” which accounts for the increasing and decreasing trend. This should not only be valid in clinical settings but should also be implemented in research (e.g. among inclusion criteria for RCTs) [10];

3.

A guideline for the recognition of patients’ needs which goes beyond the simple “get rid of headache” approach to embrace a biopsychosocial perspective, which fully accounts not only for patients’ clinical features, but also for socio‑demographic and lifestyle factors, including socioeconomic status, working environment, tasks and habits, lifestyle issues such as diet, sleep pattern, engagement in exercise, and presence of external stressors [14].

Achieving such a comprehensive migraine healthcare pathway is of primary relevance, as it may not only improve patients’ health, reduce their disability and enhance their quality of life, but it is expected to produce a significant reduction of disease costs [27, 30, 31].

Reducing medication overuse in acute management of primary headaches: strategies at primary, secondary, tertiary levels of care in a global perspective (Target 3.5)

One of the major goals of the SDG 3 by 2030 campaign is the treatment of substance abuse. Patients with chronic headache (≥ 15 headache days per month for > 3 months) frequently overuse symptomatic medications, a form of excessive intake of drugs which might drive to the development and maintenance of medication overuse headache (MOH) [31]. MOH affects 1% of the global population and is listed as a secondary headache disorder in the International Classification of Headache Disorders, 3rd edition (ICHD-3) [4]. MOH is best defined as the sequela of an inadequately managed aggressive type of primary headache, coupled with the increased use of symptomatic medications, lifestyle factors and genetic predisposition [32, 33]. Medication overuse is defined as the use of symptomatic medications for the treatment of headache on ≥ 15 days or ≥ 10 days per month, depending on the class of overused medication [4]. Commonly overused symptomatic medications for the treatment of headache include nonsteroidal anti-inflammatory drugs (NSAIDs), triptans, ergot alkaloids, barbiturates, and opioids [34]. Additionally, MOH is associated with high levels of disability, high healthcare spending, and increased healthcare consumption [27]. To reduce the burden of MOH globally, strategies targeting the primary, secondary, and tertiary level of care must be implemented. Strategies that are necessary to reach the goals of the SDG 3 by 2030 campaign include increasing primary care education in the diagnosis and treatment of common headache disorders, expanding the development of adequate care delivery systems for the treatment of headache in developing nations, and reducing the social stigma of headache and substance abuse. In addition to this, making available medications other than NSAIDs and paracetamol in those countries where other drugs are not available or affordable is also needed.

It cannot be ignored that the development of chronic and complicated headache associated to medication overuse is due to several factors, including comorbidities, genetic predisposition, psychological and lifestyle factors, and type of acute medication used [11, 12]. Among lifestyle issues, adequate sleep, eating, hydration and physical activity are the ones that can be easily tackled at all levels of care: in most cases, these are next to zero cost interventions, that are therefore particularly suitable for LMIC. Although the pathogenesis of MOH is poorly understood, most cases of MOH are associated with a progressive clinical course from EM to CM, in turn associated to the excessive consumption of medications [35]. This is supported by findings that medication overuse is present in 30% to more than 50% of patients with CM, defined as ≥ 15 headache days per month, for > 3 months, in which ≥ 8 headaches demonstrate characteristics of migraine [4, 36,37,38,39,40]. Early recognition and prescription of appropriate abortive and preventative treatment of EM at the primary care level is crucial to reduce the risk of MOH. Additionally, the treatment of MOH is complex and involves withdrawal from the overused medication [35, 41]. The concomitant use of preventative medications during detoxification may be useful in the treatment of MOH evolved from EM, but further research is needed to determine the efficacy of this approach [41,42,43,44].

Headaches are common in primary care, representing 1.5% of cases seen by general practitioners (GP) [45]. Multiple studies have demonstrated GPs’ discomfort with both the diagnosis and treatment of various primary headache disorders [46, 47]. Furthermore, recent studies demonstrated a significant underutilization of preventative medication, reporting that only 16.8% of the eligible 40.4% of migraine patients use preventative medication in the US [48] and in population setting in Europe, less than 15% of 33.8% eligible patients were treated with preventives by their GPs [49]. Underutilization of preventive medications is associated with a compensatory use of symptomatic medications at higher frequencies, increasing the potential for substance overuse and MOH [34]. To reduce the incidence of MOH, it is crucial that patients that are eligible for preventive therapy are recognized and treated early throughout the clinical course. To achieve this goal, increased education campaigns targeting patients and healthcare workers and providers of all levels should be implemented with clear guidelines describing patients that are eligible for preventive migraine therapy. This should be accompanied by policy actions to make preventive treatments which demonstrated an acceptable control over migraine activity available and affordable in all countries.

An additional concern at the primary care level is the inappropriate prescription of medications such as barbiturates, ergot alkaloids, and opioids for the acute treatment of migraine. Although many physicians continue to prescribe these medications, their use should be restricted since substantial research has demonstrated an increased risk of clinical progression and a high risk of MOH associated with these medications [50]. Rates of opioid abuse and mortality continue to rise within the USA, a phenomenon referred to as the opioid epidemic, claiming an estimated 100,000 lives per year [51]. Notwithstanding the poor efficacy of opioids in migraine and the high rates of progression to MOH associated to their use, recent research reported that 36.3% of individuals enrolled in a US population study used opioids for the symptomatic treatment of migraine [52]. This is a critical concern that requires vigorous physician education and prescribing restrictions to reduce the burden of opioid exposure for those with migraine. Additionally, patient education should involve discussion regarding the need to limit the use of symptomatic migraine medications such as NSAIDs and triptans, to a maximum number of days/month and the risks associated to medication overuse.

There are multiple barriers related to the optimal treatment of patients with MOH in developing nations, one of the leading being access to physicians trained in the diagnosis and treatment of headache, due to a lack of care delivery systems at all levels of headache treatment [46], and lack of access to appropriate medication. Neurologists are the physicians that are most likely to gain specific training in the diagnosis and treatment of headache, yet many developing nations lack the financial or institutional capabilities to support specialized medical training. Strikingly, developing nations in South-East Asia and Africa report 0.04 to 0.1 neurologists per 100,000 citizens, while in Europe the ratio is 6 per 100,000 [