ITV News can reveal that up to 10,530 outpatient appointments have been cancelled in Jersey in the last three years because of administrative errors.
That's more than double the number of those cancelled due to absent doctors.
The Health Department says figures recorded as ‘admin errors’ include system recording errors and clinic changes which may not relate to an actual cancellation of an appointment.
However, this has led to criticism from some who have criticised the department's lack of tight grip on their own data.
One retired doctor from Jersey who asked to remain anonymous told ITV News:
"If even just 500 people have had to wait while they develop complications, that's potentially 500 lives changed."
A Freedom of Information request submitted by ITV News shows that between January 2019 and December 2021, thousands of outpatient appointments were cancelled by the Health Department, rather than at the patient's request:
That contrasts with 6,784 appointments cancelled over the same period due to the Coronavirus pandemic.
Overall, the most common reason for cancelled appointments was that patients no longer required them.
However, Jersey's Health Minister - Deputy Karen Wilson - says 'it is unacceptable' that patients continue to be affected, and warned 'the situation cannot continue':
"Over the last few months, islanders have experienced unacceptable delays and cancellations regarding operations at the hospital. It is unacceptable to me as Health Minister that patients continue to be detrimentally affected."
The Minister continued: "I recognise that in some cases this may be due to matters outside of the control of those charged with providing hospital-based services in particular, and the availability of ongoing care and support in the community for those who are medically fit for discharge and workforce supply issues. However, the situation cannot continue.
"I will be meeting with officers as a matter of urgency and can assure those who are affected by appointment delays and cancellation of operations that action will be taken to reduce the delay."
Over the same three-year period, there were 2,069 "operator errors" affecting adult mental health appointments - including many cancellations.
78 adult mental health appointments were booked against the wrong patient.
Within the Child and Adolescent Mental Health Service, 635 appointments were cancelled between January 2019 and December 2021, but the reason was not recorded.
The government says the data provided does not necessarily include all appointments from across Jersey's Health Service - as some practitioners do not use a centralised electronic booking system, and some may keep paper records and diaries of cancellations and rescheduled appointments.
It also says that waiting times may have been pushed up by a surge of urgent referrals, lack of available resources and restrictions brought in during the Covid-19 pandemic.
It added that work is underway to improve data on the quality of service provided within Jersey's mental health services.