关键词: 沃文特FA280S； ,  , 复检规则； ,  , 粪便常规； ,  , 隐血试验

Abstract:

Objective　To establish and validate the re-examination rules for the ORIENTER FA280S fully automatic feces analyzer at the Dadelu Main Hospital of The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, and to improve the efficacy of routine and occult blood testing in feces samples. Methods　A total of 500 routine feces samples were randomly collected from the Dadelu Main Hospital of The Second Affiliated Hospital of Guangzhou University of Chinese Medicine between March 1 and May 31, 2024. These samples were tested using the ORIENTER FA280S fully automatic feces analyzer, with manual microscopic examination as the gold standard. χ² test was conducted to compare the results of instrumental analysis and manual smear microscopic examination, allowing for the screening of re-examination rules for the fully automatic feces analyzer. To validate the re-examination rules, 248 true-positive feces samples for any test item were collected between June 1 and August 31, 2024, and the missed detection rate was calculated. The re-examination rules were evaluated against internationally accepted criteria (false negative rate <5%). Results　For the group used to establish re-examination rules, the positive rates for red blood cells, white blood cells, fungi, parasite eggs, and occult blood test were 5.6% (28/500) , 5.6% (28/500), 4.4% (22/500), 7.2% (36/500), and 24.8% (124/500), respectively. For the validation group, the positive rates for red blood cells, white blood cells, fungi, parasite eggs, and occult blood test were 18.55% (46/248), 29.03% (72/248), 9.27% (23/248), 22.18% (55/248), and 67.34% (167/248), respectively. Five re-examination rules formulated were as below: ⑴ microscopic examination was taken when feces were loose/watery, and red/white blood cells or fungi were negative; ⑵ high-power microscopic review was done when parasites or eggs were reported by the instrument and confirmed by the analyzer's high power field and if the analyzer's field was blur; ⑶ microscopic examination for suspected red/white blood cells or fungi; ⑷ chemical re-test for occult blood was done when feces were dark, brown, or black, and the occult blood test was negative; ⑸ gold standard re-test for occult blood was done when red blood cells were positive, but the occult blood test was negative. The false negative rate for the validated re-examination rules was 4.03% (10/248), lower than 5.00%. Conclusion These rules effectively control the false negative rate, meet international standards, and satisfy testing requirements.

Key words: ORIENTER FA280S,  Re-examination rules,  Fecal routine,  Occult blood test