Description of the condition
Non-communicable diseases, also known as chronic diseases, are not passed from person to person; they are of long duration and generally slow progression (Hunter 2013; WHO 2014). The four main types of non-communicable disease are cardiovascular disease, cancer, chronic respiratory disease and diabetes (Hunter 2013; WHO 2014). In many low- and middle-income countries (LMICs) the morbidity and mortality associated with non-communicable diseases have grown exponentially over recent years (WHO 2005; WHO 2011). It is estimated that about 80% of non-communicable disease deaths occur in LMICs, which is a reflection of both the size of this population and epidemiological changes (WHO 2005; WHO 2011). In 2010, it was estimated that more than nine million of all deaths attributed to non-communicable diseases occurred before the age of 60; 90% of these 'premature' deaths occurred in low- and middle-income countries (Lim 2012). LMICs are now experiencing epidemiological transition, the change from a burden of infectious diseases to chronic diseases (Omran 1971), due to dramatic changes in diet and lifestyle. The epidemiological transition in these regions is compressed into a shorter time frame than that experienced historically by high-income countries (Miranda 2008). Urbanisation and changing behaviour practices, such as sedentary lifestyles and consumption of diets high in saturated fat, salt and sugar, are increasingly cited as the main drivers for this epidemic in LMICs (BeLue 2009; Miranda 2008; WHO 2011). In addition, LMICs are not only dealing with the emerging burden of non-communicable diseases, but also the current burden of infectious diseases (Perel 2006; Reddy 2004; Yusuf 2001a; Yusuf 2001b).
Cardiovascular diseases account for most non-communicable disease deaths, or 17.3 million people annually, followed by cancers (7.6 million), respiratory diseases (4.2 million) and diabetes (1.3 million) (Lim 2012). It is estimated that these four groups of diseases account for around 80% of all non-communicable disease deaths and they share four risk factors: tobacco use, physical inactivity, the harmful use of alcohol and unhealthy diets (Ezzati 2013; Lim 2012). Cardiovascular diseases are a group of disorders of the heart and blood vessels and they include: coronary heart disease (disease of the blood vessels supplying the heart muscle); cerebrovascular disease (disease of the blood vessels supplying the brain); peripheral arterial disease (disease of the blood vessels supplying the arms and legs); rheumatic heart disease (damage to the heart muscle and heart valves from rheumatic fever, caused by streptococcal bacteria); congenital heart disease (malformations of the heart structure existing at birth); and deep vein thrombosis and pulmonary embolism (blood clots in the leg veins, which can dislodge and move to the heart and lungs). People in LMICs are more exposed to cardiovascular risk factors (such as tobacco), often do not have the benefit of the prevention programmes available to people in high-income countries and have less access to effective and equitable healthcare services that respond to their needs (including early detection services) (WHO 2014b).
Description of the intervention
Multiple risk factor interventions (health promotion activities) are defined as interventions that address more than one cardiovascular disease risk factor at the same time, in addition to, or instead of, pharmacological treatments, in order to modify major cardiovascular risk factors. The components of multiple risk factor interventions include, but are not limited to, the following: (a) dietary advice to modify the individual's eating habits in order to reduce the percentage of calories from saturated fats, decrease the dietary cholesterol intake and increase the percentage of calories from polyunsaturated fats; (b) reducing harmful alcohol intake; (c) advice on the cessation of cigarette smoking; (d) advice on increasing daily physical activity; (e) reducing body weight; and (f) stepped care treatment of hypertension (Benfari 1981; Davey 2005; Kornitzer 1985). Since the incidence of cardiovascular disease is mainly explained by the presence of modifiable risk factors (blood lipid levels, blood pressure and cigarette smoking), reducing these risk factors through health promotion that focuses on lifestyles has been suggested as a logical way to prevent cardiovascular disease (Ebrahim 2011).
Therapeutic lifestyle modification, including increasing physical activity, changing eating habits and eliminating addictions, has been seen as a cornerstone of therapy for managing patients with metabolic syndrome (Marquez-Celedonio 2009), a clinical entity characterised by a constellation of metabolically relevant abnormalities and cardiovascular risk factors, including obesity, insulin resistance/glucose intolerance, dyslipidaemia and hypertension (Grundy 2005; Magkos 2009). Several intervention trials have reported the effects of lifestyle intervention programmes among high-risk populations (Ebrahim 2011; Mattila 2003; Muto 2001; Nilsson 2001). Some studies have recently shown a 58% decrease in the incidence of diabetes in individuals with impaired glucose tolerance (Knowler 2002; Tuomilehto 2001). Others have reported the beneficial effects of lifestyle modification on blood pressure control (Appel 2003; Appel 2003a; Elmer 2006).
Lifestyle modification has an important role to play in the lives of hypertensive and non-hypertensive individuals (Cakir 2006). In hypertensive individuals, it can serve as initial treatment before the start of drug therapy and as an adjunct to medication in persons already on drug therapy (Appel 2003a; JNC-VII 2003; Svetkey 2005; Vestfold Heartcare Study Group 2003). Lifestyle modification has been found to improve and optimise glycaemic control (Beyazit 2011). It has been documented that for optimal diabetes control outcomes, daily self management, including diet, exercise and regular self monitoring of blood glucose, is required (Beyazit 2011). Therapeutic lifestyle interventions have been found to be at least as effective as pharmacotherapies (Gillies 2007), at little cost and with minimum risk (Appel 1997). In contrast to most pharmacotherapies, lifestyle modifications can also prevent or control other chronic conditions (Knowler 2002; Stamler 1989). However, it has been suggested that in order for therapeutic lifestyle modification to be effective, it is important to pay attention not only to one single cardiovascular risk factor but to several factors simultaneously (Tuomilehto 2011). Therefore, it is generally recommended that lifestyle modifications should be implemented as a group (JNC-VII 2003).
How the intervention might work
The majority of the models of health behaviour change that are currently used as a basis for multiple risk factor interventions for preventing cardiovascular disease are derived from traditional cognitive theory (Bandura 1977a). They include the health belief model (Maimen 1974), health promotion model (Pender 1988), theory of reasoned action (Ajzen 1980; Ajzen 1985; Ajzen 1991), theory of planned behaviour (Ajzen 1980; Ajzen 1985; Ajzen 1991), self efficacy theory (Bandura 1977), and stages of change model (Norcross 2011; Prochaska 1979; Prochaska 1983). The theory of planned behaviour proposes that a person's intention to perform a behaviour is the immediate determinant of that behaviour as it reflects the level of motivation a person is willing to exert to perform the behaviour (Ajzen 1991). Another widely applied cognitive model is the stages of change model (also referred to as the transtheoretical model) (Chouinard 2007; Mochari-Greenberger 2010; Salmela 2009). The transtheoretical model sub-divides individuals into five categories (Norcross 2011; Prochaska 1979; Prochaska 1983); these represent different milestones or 'levels of motivational readiness' along a continuum of behaviour change (Heimlich 2008). These stages are: (i) pre-contemplation (the individual is unaware of the problem and there is no intention to change behaviour in the foreseeable future); (ii) contemplation (the individual is aware of the problem and there is a serious consideration of change in behaviour); (iii) preparation (the individual is willing to take action); (iv) actionable (the individual modifies their behaviour, experiences and/or environment in order to overcome the problem); and (v) maintenance (the individual works to prevent relapse and consolidate gains).
Joshi and colleagues conducted a cluster-randomised trial in rural Andhra Pradesh to develop, implement and evaluate two cardiovascular disease prevention strategies (Chow 2009; Joshi 2012). The health promotion intervention included posters, street theatre, rallies and community presentations designed to increase the knowledge of the adult population about stopping tobacco use, heart-healthy eating and physical activity (Chow 2009; Joshi 2012). The main aim of the clinical intervention was to increase the identification of people at high risk of cardiovascular events, who could benefit from proven preventive pharmacotherapies (Chow 2009; Joshi 2012). The trial found no detectable effect of the health promotion interventions on the primary outcome of knowledge about six lifestyle factors affecting cardiovascular disease risk or on either systolic or diastolic blood pressures (Joshi 2012).
The Isfahan Healthy Heart Program (IHHP) is a comprehensive, integrated, community-based programme for cardiovascular disease prevention and control, aiming to reduce cardiovascular disease risk factors and improve cardiovascular health behaviour among Iranians (Sarraf-Zadegan 2003). The IHHP advocated prevention and control of high blood pressure and diabetes, healthy eating patterns to lower cholesterol, non-smoking and regular physical activity (Sarraf-Zadegan 2003). Sarraf-Zadegan and colleagues reported that the prevalence of abdominal obesity, hypertension, hypercholesterolaemia and hypertriglyceridaemia decreased significantly in the intervention areas compared with reference areas in both sexes (Sarrafzadegan 2013).
Jeemon and colleagues examined the impact of a comprehensive cardiovascular risk reduction programme on risk factor clustering associated with elevated blood pressure using a sentinel surveillance study in an Indian industrial population (SSIP), using a population-based approach (Jeemon 2012; Prabhakaran 2009; Reddy 2006). The components of the SSIP intervention included: 1) workplace-organised individual and group counselling sessions, health displays, cooking competitions and dance classes; 2) posters, banners, handouts, booklets and real-time videos with simple, captivating messages translated into seven Indian languages for health education; 3) initiation of changes by management and employees (e.g. increasing salads and decreasing salty and fried foods on canteen menus, and enforcing smoking bans); and 4) identifying high-risk individuals through screening who were referred to the on-site health facilities for risk management (individual and group counselling was also offered). The results of the SSIP programme showed that a comprehensive cardiovascular disease risk reduction programme significantly reduced the cardiovascular risk burden (Jeemon 2012).
Why it is important to do this review
There is a comprehensive Cochrane review that has examined the effectiveness of multiple risk factor interventions in all settings, predominantly high-income countries (Ebrahim 2011). Ebrahim 2011 pooled data from 14 trials that randomised 139,256 participants and reported clinical event endpoints. They found that counselling and education interventions designed to change health behaviours do not reduce total or coronary heart disease mortality or clinical events in general populations, but they may be effective in reducing mortality in high-risk hypertensive and diabetic populations (Ebrahim 2011). The Ebrahim review, in which most studies were based in developed countries, concluded that health promotion interventions have limited use in general populations. Caution is needed in generalising evidence from high-income countries to the current LMIC context because of the differences in settings and the nature of the communities, as well as the targeted population.
One vital element in improving this situation is a comprehensive and relevant evidence base, which would equip LMICs to take informed action. To the best of our knowledge, no systematic review has been undertaken that specifically examines the effectiveness of multiple risk factor interventions for preventing cardiovascular disease in LMICs; such a review is therefore needed.