Asthma prevalence and distribution in Oman: Hierarchical modeling

In this study, we model asthma distribution and assess regional differences and we monitor its burden on the healthcare system in the Sultanate of Oman. Data for the study is collected from the Ministry of Health over a period of six years (2010 through 2015) covering all regions and by gender. We examine the differences using hierarchical modeling framework and model using the Poisson regression models to understand the multivariate effect of potential associated factors on the asthma. The significance of the study is to provide information to primarily the policy makers and implementers towards key health priority areas and to the academicians, the potential knowledge gaps for further research.

In this study, we model asthma distribution and assess regional differences and we monitor its burden on the healthcare system in the Sultanate of Oman. Data for the study is collected from the Ministry of Health over a period of six years (2010 through 2015) covering all regions and by gender. We examine the differences using hierarchical modeling framework and model using the Poisson regression models to understand the multivariate effect of potential associated factors on the asthma. The significance of the study is to provide information to primarily the policy makers and implementers towards key health priority areas and to the academicians, the potential knowledge gaps for further research.

The word ?asthma? is derived from a Greek word meaning ?breathlessness? or ?panting,? both of which describe symptoms present during an asthma attack [1]. According to [2], asthma is a disease of the bronchial tubes in the lungs (the ?airways?). It occurs in a number of people irrespective of age with wheezing as the most common symptom. ?Wheezing?, is a high-pitched whistling sound heard during breathing, especially when breathing out. Asthma is a common chronic disorder of the airways characterized by periods of reversible airflow obstruction known as asthma episodes or attacks [3, 4]. The attacks come about due to the contraction of the muscles around the airways, interrupting the airflow and thus making breathing extremely difficult.The exact cause of asthma are unknown, although a number of doctors assert that asthma is genetic and thus passed on from one person to another through the genes, but this has no scientific evidence to back it up [5]. It is also observed that a number people who show symptoms of asthma in their adulthood yet they did not present such while still young. This has casted doubt on the belief that hereditary factors are entirely be blamed for the occurrence of asthma in the victims [6].Multiple host and environmental factors may also be involved in the development of asthma and exacerbation of asthma symptoms [7]. Exposures associated with asthma attacks include exercise, airway infections, airborne allergens (e.g., pollen, mold, dust mites etc.), occupational exposures, and air pollution (e.g. tobacco smoke, particulate matter, and volatile organic compounds) (Asthma Facts, 2013). However, important to note is that these exposures that trigger an attack are different from patient to patient; as such what might be extremely dangerous for one patient may be off the list of exposures for another patient.The Global Asthma Report puts the number of asthma victims at approximately 334 million [2]. Out of all the children in the world, 14% present symptoms of Asthma. Asthma was ranked as the 14th most important disorder in as far as the extent and duration of disability is concerned [2]. The symptoms of asthma are more or less the same in both children and adults. Common symptoms during an asthma attack include: wheezing, coughing, shortness of breath, and chest tightness or pain. Asthma attacks may be mild, moderate, or severe enough to become life-threatening events (Asthma Facts, 2013). Although asthma has no cure, it can be controlled by proper medical care and better still particularly avoiding the various exposures that trigger an attack [8]. Asthma is the most common childhood condition in the world. Despite it?s prevalence being high in the countries within the gulf region [9], the knowledge gap of the distribution and risk factors associated with this disease across regions in Oman is still wide. Some attempts have been made to study estimate costs and the burden of asthma[10, 11]. However, the burden on the livelihood and health-care system caused by asthma cannot be precisely estimated without clearly understanding the regional differences in the prevalence and distribution of asthma. Asthma is categorized among the chronic disease because it has no known cure. All the medicines on the market only help to abate the symptoms. In spite of many patients outgrowing asthma as they age, doctors are never willing to declare them asthma free, insisting that the asthma episodes will always come back sometime depending on what the patient is allergic to. Globally, the Sultanate of Oman is ranked in the intermediate range by the International Study of Asthma and Allergies in Childhood [12]. The burden and associated factors is not yet established, hence, the burden and distribution of asthma patients. In the Sultanate of Oman, most asthma-related information and data are obtained from hospital records and almost none from a national population survey that would otherwise provide more extensive indicators related to factors and risk factors of asthma. Oman is listed as one of the countries with only one source of data on asthma often presented in an annual Health Report[10, 13].