NTS levels of urgency2 5
| NTS urgency level | Definition | Response time | Medical help |
| U0—Resuscitation | Loss of vital functions | Immediately | Ambulance |
| U1—Life threatening | Unstable vital functions | Within 15 minutes | Ambulance |
| U2—Emergent | Vital functions in danger or organ damage | As soon as possible, within one hour | Home visit by GP or appointment at OHS-PC |
| U3—Urgent | Possible risk of damage, humane reasons | A few hours (within three hours) | Home visit by GP or appointment at OHS-PC |
| U4—Non-urgent | Marginal risk of damage | Within 24 hours | Appointment at OHS-PC or telephone advice |
| U5—Advice | No risk of damage | Advice, no time related | Telephone advice |
GP, general practitioner; NTS, Netherlands Triage Standard; OHS-PC, out-of-hours services in primary care.