Also many health maintenance organizations position PCPs as "gatekeepers", who regulate access to more costly procedures or specialists. Ideally, the primary care physician acts on behalf of the patient to collaborate with referral specialists, coordinate the care given by varied organizations such as hospitals or rehabilitation clinics, act as a comprehensive repository for the patient's records, and provide long-term management of chronic conditions. Continuous care is particularly important for patients with medical conditions that encompass multiple organ systems and require prolonged treatment and monitoring, such as diabetes and hypertension.