Haemoglobinopathies are a group of inherited disorders of haemoglobin with over 800 recognised types. The two most important clinical syndromes are sickle cell disease and thalassaemia. Thalassaemia is due to reduced production of the affected haemoglobin chains and therefore referred to either as alpha or beta thalassaemia. Beta thalassaemia major is associated with severe anaemia and therefore dependent on blood transfusion, while other forms present a variable degree of severity with anaemia depending on the type of genetic mutation. Sickle cell disease (SCD) on the other hand is due to a single amino acid substitution of the beta chain of haemoglobin that results in the formation of abnormal haemoglobin. Among the most common SCD syndromes are sickle cell anaemia (Homozygous SS), double heterozygote such as sickle haemoglobin C disease (SC) and sickle β thalassaemia disease (Sβ) [1, 2].

The World Health Organisation estimates that over 300,000 babies with severe forms of these disorders are born worldwide each year making it the most prevalent inherited disease of mankind [1]. In the UK, SCD is particularly common among people of African and African-Caribbean origin and people whose ancestors come from the Mediterranean region, southern Europe, the Middle East and Asia [2]. There are no UK national registers for this condition but best estimates suggest that there are over 12,500 patients with SCD and about 700–800 patients with thalassaemia [3]. In England, SCD is now the most common genetic condition, affecting more than 1 in 2,000 live births. The birth prevalence in some urban areas may be as high as 1 in 300 [4, 5]. Sickle cell disease is now more more common than cystic fibrosis in England, although the distribution of cases is concentrated in London where it is about five times as common. The prevalence is also more in other urban areas [5, 6]. About 10 per cent of African-Caribbean people carry the sickle cell trait, whereas 1 in 12 Pakistani individuals carry the thalassaemia trait [7].

The central pathology in SCD is the fact that in deoxygenated states affected haemoglobin form polymers of haemoglobin and 'sickling' distortion leading to occlusion of small blood vessels. It is worth emphasising that both SCD and Thalassaemia undergo haemolysis with anaemia as a common feature. Blood transfusion therapy plays an important role as a disease-modifying strategy for several manifestations of these conditions, including very low haemoglobin, acute chest syndrome, stroke, acute intrahepatic sequestration, acute multi-organ failure syndrome, acute splenic sequestration, aplastic crisis, bacterial and malarial infections and chronic organ failure [8]. Patients may receive simple or chronic blood transfusions episodically or regularly depending on their clinical manifestations. Each transfusion of a unit of red blood cells (RBC) poses a risk of RBC antigen alloimmunisation. This is the development of antibodies to the red blood cells further compromising the success of subsequent blood transfusions. Alloimmunisation, as a result of antigenic discrepancy between patients of African ancestry and predominantly Caucasian blood donors, affects 5 to 50 percent of patients with SCD [9]. Alloimmunisation can be reduced by transfusing phenotypically matched red blood cells [10]. Such units of blood may be found in ethnically matched donors, from directed donors, or by phenotyping donor RBC components [11].

Studies in USA show that although there is a 93 percent probability that RBCs of the E-, C-, Fy (a-), K-, Jk(b-) phenotype would be from an African American donor, only about 10 percent of African Americans in an urban population donate, making it difficult to support the transfusion needs of patients with SCD with these red blood cells alone. On the other hand, although about 90 percent of Caucasian donors in this same setting donate, there is only a 7 percent probability that their RBCs would be of this phenotype [11]. Data from the UK is limited but the pattern may be similar (personal communication), necessitating the need to increase awareness of SCD within the populations at risk and establish a more effective blood donor scheme within these communities. Increased awareness about the services available, such as prenatal diagnosis, will assist at-risk individuals in making informed decisions.

The results of the newborn SCD screening programme in England 2003–2004 demonstrated that the variation in the distribution of different ethnic minority populations across the country was mirrored by the sickle cell carrier distribution [6]. Providing culturally-sensitive health information and health education to people from ethnic minorities has been a challenge due to factors which include communication difficulties and poor access to health services [13]. Religion is traditionally believed to be particularly salient to people from groups that are likely to be most affected by sickle cell disorders and thalassaemia major [14]. A potential avenue for disseminating information and increasing awareness about SCD is through the influence of religious leaders and faith organisations. Increasingly many faith organisations are being used to deliver preventive health programmes.

This review aims to examine whether religious leaders and faith organisations have the potential to influence health outcomes and health services utilization with particular reference to haemoglobinopathies. Religious leaders in this regard refers to ministers of various religions within the context of organised religiosity including priests, bishops, imams, monks etc, authoritative religious figures and scholars with capacity to influence religious practice.

Of the eleven studies reviewed four were qualitative studies, four descriptive studies, and three randomised clinical trials. The interventions were heterogeneous with four of the studies involving haemoglobinopathies, three health promotion services, and one each for smoking cessation, improving vaccination uptake, mammography promotion and use of contraception. Most of the studies (6) were carried out in the USA, two in Pakistan, one in the UK, one in Thailand and one Saudi Arabia. The findings have been categorised below based on the broad objectives of the review.

The number of patients diagnosed with sickle cell disease in the UK is increasing making it of public health relevance. Immigration is changing the demography with more adults immigrating to the UK from Africa and the Caribbean, some with sickle carrier status or with established SCD.

The NHS has shown increasing commitment to the diagnosis and management of patients with SCD over the recent years with the establishment of routine screening for sickle cell and thalassaemia and provision of guidelines for the management of sickle cell patients. However the full benefits of these services depend on their utilisation.

The majority of those affected by SCD are from the ethnic minority population. There is a large evidence base to show that disparities exist in access to healthcare services for ethnic minority populations in the UK [13], highlighting the need for a culturally appropriate means of health education and health promotion.

Religion plays a prominent role in the social and cultural life of individuals from the ethnic minority population with people identifying with a variety of faith-based groups where their leaders have a considerable measure of influence built on a combination of trust and culture. Whilst not being the only outreach medium for health education the faith community is characterised by a large population of people who show commitment, effective social and community support, socio-cultural belief systems acceptable to the groups and some element of trust in their leaders. Thus religious leaders provide potential access to this underserved ethnic minority population for health promotion, health education and improvement in utilization of health services.

The findings from the studies in this review indicate a positive outcome for the health interventions delivered through faith organisations irrespective of the mode of delivery of the intervention, whether through collaboration with health care establishments or through trained lay members of the religious community. The success of these interventions may have little to do with specific religions but more to do with the existing and effective social support system existing within faith communities and the fact that they are more likely to commit to healthier lifestyle changes or interventions. These attributes increase the chance of success for health interventions such as vaccination programmes. They may also introduce bias; thereby confounding factors during evaluation of the effects of such interventions as observed in the study by Yanek et al [19].

Some of the studies demonstrated that involvement of religious leaders were influential in encouraging the utilization of available health services, albeit indirectly. The involvement of influential Islamic scholars and their legislation on the upper limit of permissibility of pregnancy termination enhanced the utilization of health services in Pakistan and Saudi Arabia. [15, 16]. In the authors' experience individuals who were hesitant in using prenatal diagnosis were relieved to learn that Islam permitted termination of pregnancy under special circumstances and this had resulted in increased utilization of the services. Involvement and enlightenment of religious leaders on health interventions have the potential of encouraging the use of these services among their members especially if they are aware of the endorsement by their leaders.

The success of health-related interventions correlates directly with the attitude and commitment of the religious leaders to the project. Most of the studies indicated that religious leaders were willing to be involved in health related projects however some leaders may be hampered by very busy schedules, limited resources or even a distrust or suspicion of the health system or its intensions towards members of their congregation [25]. These challenges would need to be taken into consideration to ensure favourable outcomes for future interventions.

The role of religious leaders as perceived by the followers was highlighted. Their involvement in general and reproductive health programmes was perceived to be essential for the programmes' effectiveness [23]. In a telephone survey to assess barriers and motivators to blood and cord blood donation in young African-American women 17% of the participants would donate blood if encouraged by their religious leaders [26].

However, on crucial personal issues such as decisions-making about prenatal diagnosis and abortion people tended to defer to their individual faith, morals and information from relevant health personnel before making their decisions [22]. Religious leaders were perceived to be relatively uninformed about their situations from a health or scientific perspective. Religious representatives however thought otherwise, emphasizing that their role was to support people rather than tell them what to do [27].

The findings of this review are consistent with the review on effectiveness of health programmes in faith based organisations by De Haven et al [28]. Unlike this review, however, the studies were restricted to faith based organisations in the United States and were all within Christian settings. The similarity of the findings indicates that the positive health outcomes of faith based organisations are not limited by religion or geographical location.

One of the areas to explore the potential influence of religious leaders is in helping parents of newly-diagnosed SCD patients to cope with and accept the fact of the diagnosis. Many parents tend to go through a period of denial which could last from a few weeks to many years and this could potentially delay the commencement and use of antibiotic prophylaxis for their children putting them at risk for infections and other consequences.

The access provided by faith organisations for health education cannot be over-emphasised. Genetic counselling provided within a culturally sensitive environment would be helpful especially since there is a high proportion of individuals with carrier status for sickle cell disease (1 in 10) and some of them may have moral and religious reasons for not considering prenatal diagnosis or termination of pregnancy [29]. The consensus of the respondents in the aforementioned study was that SCD was best controlled through effective genetic counselling rather than through prenatal diagnosis and selective abortion of the affected pregnancies.

The potential for educating communities at risk for SCD about the condition and the role of blood transfusion in the management of haemoglobinopathies is one of the major considerations for this review. Altruism and the awareness of the need for blood are major motivators to donate blood [30]. Although data from the UK are not readily available communication with relevant staff of the National Blood Service at Tooting, London has confirmed that the proportion of blood donors from African-Caribbean origin was very low compared with Caucasians. Given the potential risk for alloimmunisation in the absence of phenotypically matched red blood cells there is need for establishment of ethnic blood donation drives. The success of The Sickle Cell Sabbath and the Charles Drew Blood donation programmes confirm this stance [18, 31]. Grassineau et al [32] reported the utilization of an anthropologic approach and cultural mediation to improve minority blood donation within a migrant community. There are in existence some local or regional blood donor drives in the UK. It is our belief that involvement of religious leaders and faith organisations would extend the reach and outcomes of such interventions.

Another potential benefit of the combination of education about SCD and the influence of religious leaders is combating the issue of stigmatization to which patients with SCD and their families are subjected.

Religious leaders are a very heterogeneous group with variations in levels of education and medical knowledge, cultural beliefs and practices, acceptance of science or perceived 'western' or modern practices, biases, variations in interpretation of their holy scripts etc. They share some of the concepts and beliefs about disease causation and inhibitions held by their members e.g. views on blood donation or transfusion. Thus there will be the need for education, enlightenment and sharing of information with religious leaders using culturally-sensitive and appropriate media in order to channel their influence on their members towards positive outcomes for health.

An important observation from this review is the paucity of published studies from the UK on sickle cell disease, haemoglobinopathies, blood compatibility issues and the role of religious organisations or religious leaders on health-related matters. There is need for more research to be carried out in the UK to add to body of evidence available locally and for purposes of comparison.

SCD is now the most common genetic condition in the UK and presents a public health challenge. Whilst improvement in health services for patients with SCD has enhanced overall management and quality of life and survival; there are still challenges for health access for many of the at-risk populations. Greater awareness and education about SCD and blood donation is necessary for these populations to encourage greater utilization of the available health services for SCD patients.

The findings from the review indicate that religious leaders and religious organisations have influence over their followers or congregations and provide potential access to these underserved, at-risk populations for increasing awareness, encouraging health service utilization and designing ethnic blood donor drives.