An IT failure that prevented NHS Tayside from being judged on waiting time performance will not be fully resolved until next month.
Patient data for a key Scottish Government target was lost during the transfer onto a new management system in June.
The Tories said the public must be able to scrutinise the health board’s performance and called for lessons to be learned from the failures, in which the previous system was “unexpectedly decommissioned”.
The blunder meant Tayside was unable to publish data on the 18-week referral to treatment standard for July to September last year – thwarting proper scrutiny of its waiting time performance.
Health bosses say a solution has now been found by their IT team and insisted local teams have known throughout how long individual patients had been waiting for treatment.
A spokeswoman for NHS Tayside said: “During the implementation of TrakCare, NHS Tayside was unable to accurately report 18-week Referral to Treatment (RTT) data due to information linkage issues.
“These issues have now been resolved by our team of IT specialists and NHS Tayside is in the process of completing an updated report of the 18-week RTT data.
“This will be completed by the end of February 2018.”
The next publication of the 18-week waiting time figures is in late February, when it is hoped all missing data can be viewed.
Miles Briggs, for the Scottish Conservatives, said: “Tayside residents deserve to have absolute faith and confidence in the accuracy of patient data and that data must also be produced in an appropriate timescale so that local people can rightly assess the performance of NHS Tayside.
“I hope that SNP ministers will continue to monitor this situation closely to ensure that all issues are resolved without further delay and that lessons can be learned from this unfortunate IT system failure.”
Earlier this month, Health Secretary Shona Robison rejected calls for an inquiry, saying she expected the reporting capabilities to be restored “early in the new year”.
“I am confident that this matter is being appropriately handled and have no plan for further enquiry – beyond ensuring that reporting capability is restored within the timeframe I mention,” she said.
She added: “To be clear – no patient data has been wiped, patient treatment has not been affected.”