The College of General Practitioners says many doctors in Auckland are still receiving what they believe to be incorrect results from laboratory tests.
The college has issued a report on several surveys conducted since a change from Diagnostic Medlab Limited to Labtests in September.
The report says there's been a definite improvement, but a third of the respondents still report experiencing delays in getting test results. Many also either believe or suspect they're getting incorrect results.
The college says a continued effort is needed by Labtests if the company is to establish widespread credibility and restore trust among doctors.
Auckland District Health Board says the service is delivering but it will take time for that to become apparent.
Chairman Pat Snedden says an evaluation by the College of Pathologists of Australasia has shown the service is up to standard.
Labtests says it is working to meet expectations.