Which of the following is characteristic of secondary care?

Secondary care primarily involves specialized medical services that are provided by healthcare professionals who do not have the first contact with patients. This level of care typically requires a referral from a primary care physician. The correct answer reflects that secondary care services are often provided in hospitals and specialized clinics rather than in the patient's home or community settings.

In terms of healthcare structure, primary care is usually where initial evaluations occur, while secondary care includes more specialized and often more complex treatments that may involve surgery, hospitalization, or advanced diagnostic tests.

While some of the other options describe relevant attributes of healthcare delivery, they do not specifically encapsulate what defines secondary care as precisely as the chosen answer does. For example, highly specialized diagnostic services can be part of secondary care, yet that doesn't encompass the full range of services. Personal treatment and preventive measures are typically associated with primary care, emphasizing routine health maintenance rather than the specialized interventions characteristic of secondary care. Lastly, while major medical centers do often provide secondary care, it is not exclusive to those environments, as secondary services can be offered in various healthcare settings. Thus, the chosen option accurately captures the essence and setting of secondary care within the broader healthcare system.