Parkinson’s disease (PD) is a neurodegenerative disorder primarily associated with motor features of tremor, rigidity, bradykinesia, and postural instability. Globally, PD has increased significantly since the 1990s [1], and it is currently the second most common neurodegenerative disorder after Alzheimer’s disease, with a worldwide prevalence of 8.5–10.8 million [1–3].

Across the Middle East, North Africa, and South Asia (MENASA), many countries have experienced an improvement in their socioeconomic status. The combination of increasing longevity and lower birth rates common with increasing wealth has contributed to an aging population and increasing prevalence of the diseases of aging. For example, when examining worldwide PD trends between 1990 and 2019, the largest increase in incidence was seen in Qatar (796.51%) and the United Arab Emirates (854.71%) [4].

The exact cause of PD is not completely understood; however, it may depend on environmental factors affecting a genetically susceptible individual [2, 5]. Caffeine, pesticide exposure, age, and family history are all factors associated with the development of PD [6]. The prevalence of PD between 65 and 69 years of age is 0.5%–1%. This rises to 1%–3% in those older than 80 [7, 8]. In one study, having a family history of PD was the strongest factor in the development of PD [6]. Caffeine was linked with a reduced risk of PD in several human and animal studies [6, 9–11]. The factors stated above differ across culturally. For example, the average annual total caffeine volume sales per capita were highest in North America, at 348 L per capita, and lowest in Africa, at 90 L per capita [12]. In addition, a study of daily caffeine intake patterns in the US found that ethnicity was one of the variables most strongly associated with intake. The difference remained significant even when employment status and weekly work hours were adjusted for [13]. Regarding genetic susceptibility, the MENASA region is characterized by high rates of consanguineous marriage, leading to a relatively high prevalence of genetic disorders. Thus, the epidemiology of PD in the MENSA region can shed light into the pathogenesis of PD. Additionally, understanding the regional necessities required to treat PD is important to prioritize research and public health policies. Overall, there is a significant lack of research on PD in the MENSA region. For this reason, the Consortium for Global Diversity in PD (CDG-PD) was established in 2020. CDG-PD comprises a network of PD experts from the MENASA region. The mission of the CDG-PD is “to improve the quality of care for people with PD through research, education and outreach.”

The CGD-PD database will provide the first large-scale, region-specific analysis of PD experiences, treatments, and care models in MENASA. The insights gained will help improve patient quality of life, enhance caregiver support, and guide healthcare policies to provide better and more equitable PD care.

In this paper, we present the study protocol of a multicenter database of patients with PD in the MENASA region that was created as a result of the CDG-PD initiative. The aims of establishing this database are to [1]: describe the clinical characteristics of PD patients in the MENASA region [2], explore the current treatments and level of care for patients with PD across centers in the MENASA region [3], assess the socioeconomic and financial burden of PD in the MENASA region [4], explore the relationship between PD-related treatments and levels of care with patient-perceived current health status, and [5] explore the relationship between environmental exposure and clinical characteristics of PD patients in the MENASA region.

The development of this consortium and regional database is the first step towards helping healthcare professionals, researchers and health policymakers to better understand PD and to improve the care of people with PD in MENASA. The development of the database will also help in the future in identifying patients who may wish to participate in clinical trials, facilitate efforts for quality improvement required to enhance the quality of life of people with PD, and generate recommendations for patient education, healthcare professionals and policymakers.

Table 2 provides a comprehensive overview of patient characteristics to be reported using descriptive statistics upon completion of data analysis. This includes demographic and socioeconomic factors; clinical and behavioral characteristics; PD-related symptom severity, surgical history and medication use; residential and environmental exposures; health coverage; and financial toxicity-related assessments. Each variable is detailed alongside its corresponding data format (Table 2). Multilevel ordinal logistic regression will be employed to assess the relationships between PD-related treatments and levels of care (including PD-related surgery, medication use, and various therapies) with patient-perceived current health status. Crude and adjusted odds ratios (ORs), along with 95% confidence intervals (CIs), will be reported and presented in a table as measures of these associations.

Multilevel binary and ordinal logistic regression models will be employed to assess the relationships between previous histories of environmental exposures and the following PD-related outcome variables: rest tremors, dyskinesia, visual hallucinations, memory decline, freezing episodes, sleep disturbances, sleep behavior disorder, rapid eye movement sleep behavior disorder, Dopamine Dysregulation Syndrome, and PD symptom severity. The previous histories of environmental exposures to be explored include living near farm fields, the main source of drinking water, working in plumbing, welding, or soldering, exposure to heavy metals, mixing or applying pesticides, and drug use. Similarly, crude and adjusted ORs and 95% CIs will be reported and presented in a table as measures of these associations.

Over the last 25 years the prevalence of PD has risen in the MENASA region potentially as a result of aging population, sedentary lifestyle and expanding industrialization [14–16], however, prevalence of the disease in Asians and Blacks is reported to be 50% less as opposed to Whites [14, 16]. There is a need for accurate epidemiological data and to understand patients’ clinical characteristics and current practices in the region. Such data are crucial for assessing population needs, developing policies, and allocating healthcare and research resources. The urgent need for studies to understand PD related factors in this region has also been previously emphasized [14].

The primary aim of creating this consortium and database is to investigate the demographic and clinical attributes of patients with PD and the care provided for this population in the MENASA region. Large scale multicenter observational studies are important prerequisites for translational and interventional PD research in the MENASA region. Understanding the effect of PD on the overall wellbeing and daily functioning of affected individuals will provide the base for future follow-up pharmacological and non-pharmacological studies to manage these symptoms, facilitate early diagnosis, and improve quality of healthcare. Overall, the regional and ethnic disparities impact both the prevalence of PD and its clinical features. [14]. We suspect that the disease phenotype in MENASA region may be influenced by unique genetic, environmental and cultural factors. Our study may help identify additional risk factors that may not have been observed in Western countries yet. For instance, high rates of marriages between relatives in MENASA countries may be a risk factor for the region’s relatively high prevalence of genetic diseases [14, 17]. In many rural regions of MENASA countries, a large number of farmers are regularly exposed to various pesticides, which have been recognized as a contributing factor for development of PD [14, 15]. Although rural living has been cited as a potential factor for PD progression, a US based study found a higher rate and occurrence of PD in urban as compared to rural population [16]. The same study proposed debatable role of single toxin exposure such as pesticides or industrial toxins in development of PD [15]. On the contrary, the high prevalence of PD in Egyptian cities near the Nile Valley has been suggested to be attributable to industrial poisons draining into the Nile river [16]. Therefore, the current database can help identify cultural and environmental risk factors which may be unique to the MENASA region, as well as factors with are similar to those in western countries. Understanding these factors can improve the quality of care provided for these individuals and guide researchers in their interventional studies. Cultural variations such as lack of awareness about the disease, stigma regarding cognitive impairment and sexual dysfunction, and lack of health-related resources are few of the factors that we believe may rise in this study that may be considered unique to the MENASA region. We believe that some of the aforementioned cultural factors may directly influence data collection. Social stigma that is often present among different neurological conditions in the MENASA region may lead to symptom underreporting [17], especially symptoms such as depression and cognitive impairment. Hesitancy to participate in research has been previously reported in PD due to variability in healthcare access in the MENA region [18]. Religious beliefs, specifically those regarding destiny and illness may also influence the participation in research [19]. To overcome these possible factors, researchers in this study will collect data from various healthcare settings and recruit patients from different geographical and socioeconomic backgrounds. The researchers will also ensure anonymity and confidentiality of the collected data.

On the other hand, it is speculated that illiteracy in many MENASA countries may be the cause of delayed diagnosis, which in turn leads to undue delay in commencement of treatment and consequently poor wellbeing of PD patients [20]. There is a significant relationship between patients’ educational background, understanding the need for treatment, and consistency in compliance with medications and rehabilitation. Lack of availability of patient educational material and support groups in regional languages are other barriers that may contribute to poor patient understanding of disease and compliance to treatment [21]. Regional consensus showed significant need for developing educational programs for both patients and healthcare professionals [20]. Accessible high quality educational programs supported by the participation of professionals that provide care and support for PD patients are essential for better patients’ care, such as neurologists, researchers, PD nurses, and allied healthcare professionals. For example, supporting interested individuals to study in other countries under supervision, holding symposia directed toward delivering updates in the field, is anticipated to contribute to this regard.

This database will eventually provide real-world data that will help establish public health campaigns and initiatives to advocate PD patients, raising awareness and providing education. The database can also improve training and education for healthcare professionals through the establishment of continuing medical education (CME) programs providing healthcare workers with the best available evidence and updated practices in PD care.

Understanding regional PD treatment needs is also critical in prioritizing public health initiatives. Availability and affordability of PD treatment could be barriers to improving the quality of life of PD patients. Recent studies have shown the high economic burden of PD on the patient and the family in several MANASA regions [14, 15]. In many countries in the region, patient’s out-of-pocket cost is significantly high due to a lack of national healthcare coverage and private healthcare insurance coverage [20]. Furthermore, lack of access to device assisted therapies such as Deep Brain Stimulation (DBS) or infusion therapies may adversely affect the outcome of patients with advanced disease [20] Levodopa-carbidopa intestinal gel (LCIG) and continuous subcutaneous apomorphine infusion (CSAI) are examples of existing infusion therapies that are often used as an alternative option to oral medications in PD patients with inadequately controlled symptoms [20].

A multidisciplinary approach is the key to improving the quality of life of PD patients, given the complexity of the disease [22]. To help PD patients maintain maximum level of independence, physical rehabilitation therapies have been established as a supplement to medication use [5]. Reportedly limited availability of specialized physical, occupational, and speech rehabilitation contributes to adverse outcome of the disease [20, 21]. Deeply rooted sedentary lifestyle of most MENASA countries, lack of interest in exercise and absence of health insurance coverage may be barriers to rehabilitation. Besides this, women and older individuals of this region rely heavily on their families for transportation and access to rehabilitation services, making rehabilitation difficult to manage [21]. In addition to that, personalized care for PD patients is often achieved by professionals trained to provide support and deal with individual issues in PD. Parkinson’s Nurses (PN) are specialized to provide such care and have been shown to provide a pivotal role in the primary care of PD patients [15, 23]. In the MENASA region, a consensus statement by the MDS task force generated a priority need to have specialized professionals in movement disorders in this region [24]. This emphasizes the need to establish the PD database to facilitate the identification of gaps in the multidisciplinary care provided for PD patients in the MENASA region, to eventually help establish such needed interventions.

A significant limitation in the current multidisciplinary team providing care for PD patients in the MENASA region is the absence of PD nurse experts in the majority of participating centers. While professional nurses are essential in providing patient education, medication management, emotional support, and symptoms monitoring [25, 26]. This service is not available in most of the MENASA regions. This gap may lead to increased demands on neurologists, limited patient access to interventions on time, and discontinued disease management [27]. Identifying this limitation is crucial as it underlines the gap for potential improvement in the healthcare policy. Additionally, by adding data from centers with PD nurses to the database, future research may evaluate their impact on patient outcomes. A comparison between centers with and without specialized PD nurses could provide significant evidence of their important role in enhancing the quality of care for PD patients.

This database will provide an up-to-date status of the healthcare system provided for individuals with PD in the MENASA region. It will help understand region specific epidemiology, genetic predisposition, risk factors, clinical presentation, drug responsiveness, economic burden and quality of life of PD patients. Findings from this data can highlight the need to improve the quality of healthcare provided for these patients. Healthcare providers, researchers, and policymakers can utilize the findings from this study to improve the management options available for these individuals in the MENASA region and even globally in other underserved regions. This can be achieved by developing new therapeutic approaches and models of care for these individuals that are culturally and environmentally appropriate. Information from this database can help researchers identify environmental and genetic factors that are unique to the MENASA region. This will advance clinical research and lead to personalized treatment strategies. Healthcare providers can utilize patient data to capture the multidimensional PD symptom nature and eventually develop holistic care models. Furthermore, drug development can be enhanced by using the data to test new drugs, optimize existing treatments, and reduce adverse effects. Policymakers can generate recommendations and regulations that are evidence-based to prioritize the healthcare provided for these individuals as well as allocating funds to improve the resources available. For example, governments and policymakers can allocate resources effectively, establish financial aid programs, adjust insurance coverage, and ensure patients with PD have access to proper diagnostic tools, medications, and multidisciplinary care. Extending beyond the region, this database can eventually provide an opportunity for international researchers from global institutions to collaborate with MENASA institutions to exchange knowledge, develop new PD treatments, and foster global discussions.