The role of ancillary services in client-centred systems of care.

The studies in this issue reflect the operation of the Ryan White CARE Act's holistic model of health and support services for people living with HIV in the USA. Ancillary services available through the CARE Act are responsive to predisposing factors, enabling factors, and system characteristics that pose barriers to clients' receipt of primary medical care. That nearly all of the studies use cross-sectional rather than longitudinal data makes it difficult to draw causal inferences. Taken as a whole, however, the studies suggest that receipt of ancillary services such as case management, mental health and substance abuse treatment, transportation, and housing assistance is associated with primary care entry and retention among CARE Act clients. The studies and the literature out of which they arise suggest that there is a need to refine further our understanding of care systems so that we can refine the care systems themselves. Among the concepts proposed for the study of care systems are comprehensiveness, capacity, coordination, integration, cultural competence, and client-centredness.