The number of people in Northern Ireland waiting for a first outpatient appointment has increased by almost 37 per cent over the last year, according to the latest figures.
During the month of December 2015 there were 236,365 people on waiting lists compared to 171,866 the previous year.
The number of people waiting more than 18 weeks for a first outpatient appointment has more than doubled.
Ulster Unionist spokesperson on health Jo-Anne Dobson said the fact that more than one in five of Northern Ireland’s population - almost 400,000 people - are now on a hospital waiting list for a diagnostic test, hospital appointment or treatment, is the “most acutely felt failure of the current Executive”.
Mrs Dobson said: “For many people, increased waiting times – whether it be for diagostic test or treatament – can be hugely detrimental.
“Waiting time targets exist for sound medical reasons as it is proven that the longer a patient waits for treatment, the greater the risk that they may come to harm.
“Indeed, our own Health and Social Care Board openly acknowledges that delayed diagnosis of serious or life-threatening conditions means there is a much reduced likelihood of a successful outcome. People’s lives are being put at risk.”
Targets for diagnostic waiting times were also breached.
While Department of Health guidelines state that no patient should wait more than nine weeks for test results, the figures at the end of last year show that 35.7 per cent of patients - more than 33,000 people - were waiting longer than that.
In November last year, Health Minister Simon Hamilton said he was allocating £40 million to tackle the problem.
The SDLP’s Fearghal McKinney described the latest waiting list figures as “shocking and unnacceptable”.
Mr McKinney said: “The figures speak for themselves and the human stories behind them are sometimes horrendous. The extra money given last year is a drop in the ocean and today’s statistics show that it has had very little impact.”