Effectiveness of shared care across the interface between primary and specialty care in chronic disease management

BACKGROUND: Shared care has been used in the management of many chronic conditions with the assumption that it delivers better care than either primary or specialty care alone. It has been defined as the joint participation of primary care physicians and specialty care physicians in the planned delivery of care, informed by an enhanced information exchange over and above routine discharge and referral notices. It has the potential to offer improved quality and coordination of care delivery across the primary-specialty care interface and to improve outcomes for patients. OBJECTIVES: To determine the effectiveness of shared-care health service interventions designed to improve the management of chronic disease across the primary-specialty care interface. SEARCH STRATEGY: We searched the Cochrane Effective Practice and Organisation of Care Group (EPOC) Specialised Register (and the database of studies awaiting assessment); Cochrane Central Register of Controlled Trials (CENTRAL); Database of Abstracts of Reviews of Effects (DARE); MEDLINE (from 1966); EMBASE (from 1980) and CINAHL (from 1982). We also searched the reference lists of included studies. SELECTION CRITERIA: Randomised controlled trials, controlled before and after studies and interrupted time series analyses of shared-care interventions for chronic disease management. The participants were primary care providers, specialty care providers and patients. The outcomes included physical health outcomes, mental health outcomes, and psychosocial health outcomes, treatment satisfaction, measures of care delivery including participation in services, delivery of care and prescribing of appropriate medications, and costs of shared care. DATA COLLECTION AND ANALYSIS: Three review authors independently assessed studies for eligibility, extracted data and assessed study quality. MAIN RESULTS: Twenty studies of shared care interventions for chronic disease management were identified, 19 of which were randomised controlled trials. The majority of studies examined complex multifaceted interventions and were of relatively short duration. The results were mixed. Overall there were no consistent improvements in physical or mental health outcomes, psychosocial outcomes, psychosocial measures including measures of disability and functioning, hospital admissions, default or participation rates, recording of risk factors and satisfaction with treatment. However, there were clear improvements in prescribing in the studies that considered this outcome. The methodological quality of studies varied considerably with only a minority of studies of high-quality design. Cost data were limited and difficult to interpret across studies. AUTHORS' CONCLUSIONS: This review indicates that there is, at present, insufficient evidence to demonstrate significant benefits from shared care apart from improved prescribing. Methodological shortcomings, particularly inadequate length of follow-up, may partially account for this lack of evidence. This review indicates that there is no evidence to support the widespread introduction of shared care services at present. Future shared-care interventions should only be developed within research settings and with account taken of the complexity of such interventions and the need to carry out longer studies to test the effectiveness and sustainability of shared care over time.