Deviation of diagnostic analyser incident in Tuen Mun Hospital

The following is issued on behalf of the Hospital Authority:

     The spokesperson for Tuen Mun Hospital (TMH) made the following announcement today (July 22) regarding an incident of deviated reference ranges of an alkaline phosphatase analyser:

     When an alkaline phosphatase analyser was installed at the Department of Clinical Pathology in TMH in 2013, the reference ranges of male and female patients for the age group 60 or above were swapped inadvertently. TMH had rectified the reference ranges immediately when it was recognised during an inspection of medical equipment on July 6 this year.

     Alkaline phosphatase analysis is usually regarded as one of the indicators of liver function test. When printing the reports, apart from the exact alkaline phosphatase reading of the patient's blood sample, the analyser would also state a reference range according to gender and age group of the patient. In normal circumstances, the reference range for male patient for the age group of 60 or above should be from 56 to 119 U/L, and female should be from 53 to 141 U/L. When the patient's alkaline phosphatase reading exceeds the reference range, it represents one's liver function or bone metabolism may experience abnormal situation and further examination may be necessary.

     In general situation, when formulating the treatment plan, the case doctor would make reference to various assessments such as different pathological examinations, data, medical history and clinical symptoms, while the alkaline phosphatase reading is only one of the references. Thus, the reference range provided on report is only a reference tool for doctor to consider patient's alkaline phosphatase level.

     It was believed that the deviation occurred when the analyser was installed in the Department of Clinical Pathology in August 2013. At that time the reference ranges of male and female patient for the age group 60 or above were swapped inadvertently, leading to the reference range of male patient being set at 53 to 141 U/L while female patient at 56 to 119 U/L.

     Given the reference range of female patient was tightened, some female patients with normal liver functions or bone metabolism might have undergone repeat examinations such as blood test or liver ultrasound to confirm any abnormality, but there was no effect to the treatment they had received. However, as the reference range of male patient was relaxed, some male patients whose reading exceeded the reference range might mistakenly be regarded as normal.

     Following a comprehensive examination, it is confirmed that only the reference range was affected. The results of alkaline phosphatase analysis performed by the analyser were accurate. It was thus believed the incident has caused very minimal risk to patients' treatment and health condition.

     In order to address the concerns of patients involved, after consulting the experts from the Hospital Authority Central Co-ordinating Committee in Pathology, TMH has decided to  thoroughly review the reports of all 4,634 male patients concerned. Among the 1,065 reports we have already reviewed so far, there are 236 patients need to be called back for further examinations to confirm their health condition.

     The TMH will continue to review the remaining 2,144 reports at the earliest possible. Initial reviews show that most of the patients are either having medical follow up or their alkaline phosphatase level have already been back to normal. It is reasonable to estimate that the numbers of patients need to be called back for medical examinations should be minimal.

     Among the patients concerned, 1,425 had already succumbed due to various causes. After initial review of their records, there is no indication showing their death was related to the incident. However, TMH will prudently review their records to ascertain the cause of death.

     The New Territories West Cluster is highly concerned about the incident and has reported to the Hospital Authority Head Office (HAHO). The Cluster will set up an investigation panel with representatives from HAHO and independent pathologist, to thoroughly investigate the root cause of the incident and to make recommendations. The panel will submit the report to HAHO within eight weeks.

     TMH expresses sincere apology to the patients concerned. A telephone hotline 64680016 has been set up for patient enquiries. The Patient Relation Officer of TMH would render necessary assistance to patients in need.

Ends/Wednesday, July 22, 2015
Issued at HKT 19:55