"Global Journal of Health Science; Vol. 7, No. 2; 2015ISSN 1916-9736 E-ISSN 1916-9744Published by Canadian Center of Science and EducationAn Overview of Chronic Disease Models: A Systematic LiteratureReview1 2Ashoo Grover & Ashish Joshi 1Indian Council of Medical Research, Government of India, New Delhi, India 2Center for Global Health and Development, College of Public Health, University of Nebraska Medical Center,Omaha, Nebraska, USACorrespondence: Ashish Joshi M.D., PhD, MPH, Assistant Professor, Center for Global Health and Development,College of Public Health, University of Nebraska Medical Center, Omaha, NE, USA. Tel: 1-402-559-2327, Fax:1-402-559-2330. E-mail: [email protected]: March 13, 2014 Accepted: August 18, 2014 Online Published: October 28, 2014doi:10.5539/gjhs.v7n2p210URL: http://dx.doi.org/10.5539/gjhs.v7n2p210 AbstractAims: The objective of our study was to examine various existing chronic disease models, their elements andtheir role in the management of Diabetes, Chronic Obstructive Pulmonary Disease (COPD), and Cardiovasculardiseases (CVD).Methods: A literature search was performed using PubMed and CINHAL during a period of January 2003-March 2011. Following key terms were used either in single or in combination such as “Chronic Disease Model”AND “Diabetes Mellitus” OR “COPD” OR ‘CVD”. Results: A total of 23 studies were included in the final analysis. Majority of the studies were US-based. Fivechronic disease models included Chronic Care Model (CCM), Improving Chronic Illness Care (ICIC), andInnovative Care for Chronic Conditions (ICCC), Stanford Model (SM) and Community based Transition Model(CBTM). CCM was the most studied model. Elements studied included delivery system design andself-management support (87%), clinical information system and decision support (57%) and health systemorganization (52%). Elements including center care on the patient and family (13%), patient safety (4%),community policies (4%), built integrated health care (4%) and remote patient monitoring (4%) have not beenwell studied. Other elements including support paradigm shift, manage political environment, align sectoralpolicies for health, use healthcare personnel more effectively, support patients in their communities, emphasizeprevention, identify patient specific concerns related to the transition process, and health literacy between visitsand treatments have also not been well studied in the existing literature.Conclusions: It was unclear to what extent the results generated is applicable to different populations andlocations and therefore is an area of future research. Future studies are also needed to test chronic disease modelsin settings where more racially and ethnically representative patients receive chronic care. Future programdevelopment should also include information on other barriers including transportation issues, finances and lackof services.Keywords: Chronic Disease Model, elements, CVD, Diabetes and COPD1. IntroductionChronic diseases are diseases of long duration and generally slow progression. As per World Health Organization(WHO), the four main types of chronic diseases are cardiovascular diseases (like heart attacks and stroke),cancer, chronic respiratory diseases (such as chronic obstructed pulmonary disease and asthma) and diabetes(Alwan, 2011). Chronic diseases are by far the leading cause of death in the world, representing over 60% of allannual deaths. Of the 57 million deaths that occurred globally in 2008, 36 million were due to chronic diseasescomprising mainly cardiovascular diseases, diabetes, chronic lung diseases and cancers (Alwan et al., 2010)About one fourth of global chronic disease related deaths took place before the age of 60 years. Some 80% of allchronic disease deaths occurred in low- and middle-income countries. The burden of chronic diseases is risingfastest among lower-income countries, populations and communities and is projected to increase substantiallyover the next 2 decades (Ezzati, Lopez, Rodgers, & Murray, 2005). 210 www.ccsenet.org/gjhs Global Journal of Health Science Vol. 7, No. 2; 2015Diabetes represents a significant public health problem worldwide by decreasing quality of life and causingdeath and disability at great economic cost. Though quality diabetes care is essential to prevent long termcomplications, care often falls below recommended standards regardless of health care setting or patientpopulation, emphasizing the necessity for system change. Cardiovascular disease (CVD) is the leading cause ofdeath worldwide accounting for approximately 18 million deaths a year (Ezzati et al., 2005). CVD is also theleading cause of mortality in developing countries. Mortality from ischemic heart disease in developing countriesis expected to increase by 120% for women and 137% for men (Leeder, Raymond, Greenberg, Liu & Esson,2004). The respiratory diseases, including asthma and chronic obstructive pulmonary disease (COPD), caused4.2 million deaths in 2008 and 90% deaths occurred in low and middle income countries (Ezzati et al., 2005).The World Health Organization estimates that there will be a significant economic impact of chronic diseasesworldwide. In 2005, the estimated loss in national income from heart disease, stroke and diabetes was 18 billiondollars in China, 11 billion dollars in Russian Federation, 9 billion dollars in India, and 2.7 billion dollars inBrazil. Similarly, the losses for UK, Pakistan, Canada, Nigeria and the United Republic of Tanzania were 1.6billion dollars, 1.2 billion dollars, 0.53 billion dollars, 0.4 billion dollars and 0.1 billion dollars respectively.Three quarters of health care expenditure in United States is on chronic disease bills (US $ 1-7 trillion per year)(WHO, 2011). The results indicate that the burden of chronic diseases poses appreciably greater constraints toeconomic performance in low and middle income countries. The estimates do not include the life-time cost ofmorbidity, disabilities, and foregone expected lifetime earnings of individuals (Abegunde & Stanciole, 2006).Age related changes, complicated by multiple, progressive physical, cognitive and emotional health problemscontribute to accelerate functional decline, poorer quality of life and decreased survival rates. The constraints onlimited resources, time and adequate information further adds to the challenge for the decision making process.Decision-makers at the population and individual levels each need to choose the best intervention for a specifichealth problem and this is particularly true for chronic diseases (Wagner, Davis, Schaefer, Von, & Austin, 2002).Chronic disease management has been a difficult challenge because of several factors including lack ofinformation technology in outpatient settings; multiple sources of nonintegrated information; limited access toand use of specialists including education services; and time constraints.Addressing increased incidence of chronic disease is one of the most important challenges for the health system.In contrast to the traditional medical model management of acute conditions, management of chronic diseaserequires that patients take a more active role in the day-to-day decisions about the management of their illness.This new disease paradigm requires that there be a working patient-provider partnership that involves effectivetreatment within an integrated system of collaborative care. The essential ingredient of effective chronic caremanagement is the partnership between the patient and health professionals because it offers the opportunity toempower patients to become more active in managing their health. When patients are more informed, involved,and empowered, they interact more effectively with healthcare providers and strive to take actions that willpromote healthier outcomes (Bodenheime, Lorig, Holman, & Grumbach, 2002). The patient is central to definingthe disease-related problems and the self-management program assists them with problem solving and gainingthe self-efficacy and confidence to deal with the problems. A large diversity of chronic disease models exist in the literature. Different models have different elements toconsider. Some consider self-management; others have health systems approach, and few have communityparticipation approach while others include selected chronic diseases treatments. However, model constructionand development is complex and difficult. Critiquing and providing a comprehensive overview of all models is achallenging task.The objective of our study was to systematically review and evaluate the strengths and limitations of existingchronic disease models and their applications towards the management of most common chronic diseases such asDiabetes, COPD and CVD. 2. Materials and Methods2.1 Search MethodologyAll searches in Pubmed and CINHAL were conducted with the following limits: date range from 1/1/2003 to31/3/2011, search term used was “Chronic disease model” OR “Chronic Care Model” AND “Diabetes” OR“COPD” OR “Cardiovascular Diseases”; studies should focus on humans, be in English and should be eitherclinical trial, controlled clinical trial, randomized controlled trial, journal article, practice guideline, orgovernment publications. A series of searches was conducted on MeSH entry terms. The inclusion criteriaincluded articles that described the origin of the chronic disease model, its rationale and their elements. 211 www.ccsenet.org/gjhs Global Journal of Health Science Vol. 7, No. 2; 2015Exclusion criteria for the search terms included duplicate terms, not related to chronic diseases, had infectiousdisease focus, genetics studies and did not specify chronic disease model. Articles involving genetics, treatments,or biomarkers of chronic diseases were excluded as were case reports, meta-analyses, and reviews. The lists ofarticles retrieved were saved as text files and as saved searches within PubMed's My NCBI feature. An overviewof the search strategy is shown in Figure 1. Article lists were compiled using PubMed's “Collections” feature inorder to group all the articles and to eliminate duplicate articles. Key word Search Search Limits Chronic Disease Model Human, English, Reviews,Metaanalysis, Govt.Publications, Multicentrestudies, Comparativestudies, randomizedcontrolled trial,PubMed N=8,756 CINHAL N=53 Exclusion criteria Not related to chronic diseases Had infectious disease focus Genetics studies Chronic diseases other than diabetes,CVD and COPDDuplicate articles in Pubmed andCINAHLExclusion criteria Chronic disease includingPubMed CINHAL N=3 those other than the focusof the studyN=53 Exclusion criteriaSystematic review andInclusion criteriaMeta analysis articlesDescription of chronic diseaseexcludedmodelFinal Analyzable Sample Description of either one or moreN=23elements of chronic disease modelFigure 1. Overview of the search methodology2.2 Data ExtractionTable 1 shows variable extracted for the study.212 www.ccsenet.org/gjhs Global Journal of Health Science Vol. 7, No. 2; 2015Table 1. Information about the various variables extracted for the overview of chronic disease modelsStudy year Information was recorded on the number of studies that were published during the various years from2003-2011Study location Information was recorded on the location of the studies including U.S. versus non U.S. based andwhether or not the studies were done in rural or urban settings.Study design Information was also recorded if the studies were observational or randomized controlled clinical trialsand if they were interventional or not.Studies follow up The duration of the studies was also recorded to examine the impact of the chronic models onlongitudinalDisease studied The review is focused on diseases including Diabetes, Chronic Obstructive Pulmonary Disease andCardiovascular diseases because of their predominance in resulting death and disability worldwide. Chronic disease Information was recorded on the specific chronic disease models and their elements that weremodel and its described and evaluated across all these studieselementsOutcomes assessed Information was also recorded about the various outcomes that were measured in these studies. 2.3 Statistical Analysis Descriptive analysis was performed to report frequency analysis on the various variables that were extracted witha particular emphasis on the various chronic disease models and its elements. Additional analysis was performedto examine the distribution of the process, clinical and non-clinical variables. Stratified analysis was performedto determine frequency of the health outcomes studied. Stratified analysis was performed to examine the changein the various outcomes that were assessed. The stratification analysis was performed by chronic diseaseelements studied and the chronic diseases studied such as CVD, DM and COPD. All analysis was performedusing SAS V9.1.3. ResultsThe study identified 8,756 articles from PubMed search and CINHAL search resulted in 53 articles. Afterapplying the relevant inclusion and exclusion criteria as described, 53 articles were found relevant to the study.The articles were reviewed and those which had included information about the specific chronic disease modeland their associated elements were included in the final analysis resulting in an overall analyzable sample of 23articles (Table 2).213 www.ccsenet.org/gjhs Global Journal of Health Science Vol. 7, No. 2; 2015Table 2. Summary of different elements of chronic disease models studied during 2003-2011 (Diabetes Mellitus,CVD and COPD). The X sign indicates that an element of a specific chronic disease model was studied primarilywhile + sign shows the presence of similar element being a part of other chronic disease model. The + signshows an overlap of different elements for various chronic disease modelsChronic Disease Models 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 NWagner CCMHealth system or Health organization + X X X X X X X X X X X 11Clinical Information System (CIS) X X + X X X X X X X X X X 12Decision support + X X X X X X X X X X X X X 13Delivery system design X X + X X X X X + X X X X X X X X X X X X 19Self management support X X X + X X X X X + X X X X X X X X X X X 19Community linkages+ X X X X X X X X 8Improving Chronic Illness Care Patient safety (in Health System) X 1Cultural competency (in Delivery System+ X + 1Design)Care coordination (in Health System and X + + + 1Clinical Information Systems)Community policies (in Community X 1Resources and Policies)Case management (in Delivery System X + 1Design)Innovative Care for chronic conditions Support a paradigm shift 0Manage the political environment 0Build integrated health care X 1Align sectoral policies for health 0Use healthcare personnel more effectively 0Center care on the patient and family X X X 3Support patients in their communities 0Emphasize prevention 0Stanford ModelSelf Management + + + + + + + X + + + + + + + + + 1Transition Care Model patient-specific concerns related to the 0transition processMedication adherence and persistence 0Health literacy between MD 0visits/treatmentRemote patient monitoring X 1The majority of the articles were US-based (n=18/23), followed by New Zealand (n=2/23) and one each inAustralia, Switzerland and Italy. More than half the studies were interventional (n=12/23), followed by crosssectional (n=10/23) and one study was a descriptive study (N=1). The average follow up period in these studiesranged from 18 weeks to 4 years. Only two studies were done in rural settings that implemented chronic disease214 "