Which of the following is a medical intervention factor that affects infection risk?

• A. Indwelling devices
• B. Hand hygiene
• C. Age
• D. Nutritional status

Answer: (A)

Medical intervention factors are elements of care that involve invasive devices or procedures introduced by healthcare workers, which can create routes or surfaces for infection. Indwelling devices, such as urinary catheters, IV lines, implanted hardware, or chest drains, stay inside the body and can harbor bacteria or form biofilms. They bypass some natural barriers and provide direct access to sterile sites, so infection risk increases the longer the device is in place and the more complex the care required. This makes them a prime example of a medical intervention factor that elevates infection risk. In contrast, hand hygiene is a prevention practice to reduce risk, while age and nutritional status are host-related factors reflecting immune strength, not a feature of the care intervention itself.