According to the WHO, which of the following is NOT a key aspect of a healthcare system?

The World Health Organization (WHO) emphasizes several key aspects of effective healthcare systems, and understanding these elements is crucial for analyzing healthcare quality and efficacy. In this context, while cost is a significant consideration in the operation and financing of healthcare systems, it is not categorized as a core aspect by the WHO.

Access refers to the availability of healthcare services to individuals, ensuring they can receive necessary services without barriers. Quality involves the standard of care provided, which is essential for positive health outcomes and patient satisfaction. Sustainability relates to the system's ability to maintain health services over time, preserving resources and adaptability to changing conditions.

While cost may heavily influence how healthcare systems are designed and managed, it does not represent a fundamental attribute defining the essence of a healthcare system according to WHO guidelines. Instead, cost considerations are often seen as underlying factors that impact how access, quality, and sustainability are achieved. Therefore, the identification of cost as not being a key aspect aligns with the WHO's focus on the primary attributes necessary for a successful healthcare system.