Waiting times to see a medical specialist are on the rise across the country, the healthcare watchdog NZa has warned.

In the most extreme cases patients are having to wait 48 weeks between requesting an appointment and seeing the relevant specialist for the first time. The problem is particularly acute for illnesses associated with old age.

Hospitals and clinics have agreed national maximum waiting times of four weeks for a diagnosis and seven weeks for the start of clinical treatment, but there are no sanctions for exceeding the limit.

The northern provinces of Groningen, Drenthe and Friesland had the worst overall record, caused by a combination of an ageing population and a shortage of medical staff. The Scheper hospital in Emmen topped a league table of aggregate waiting times compiled by the NZa; the combined waiting time for all types of treatment was 139 weeks.

Other areas struggled in specific areas, such as Rotterdam and Noord-Friesland, where cardiac patients face longer waits for treatment. The NZa said healthcare providers and insurers needed to stop blaming each other and work together to improve the situation for patients.