Research question

What are the changes in the use of four types of counting chambers by laboratories enrolled in an Australian-based external quality assurance programme, and what are their accuracy and precision?

Design

Samples of latex beads of known concentration up to 20 × 10⁶/ml were distributed quarterly to enrolled laboratories over a 12-year period. The results of each distribution were then used to calculate a bias relative to the target value as an indicator of accuracy and a coefficient of variation to indicate the level of precision.

Results

The proportion of laboratories in 2007–2008 using improved Neubauer haemocytometers (44%), Makler® (9%) and Vetriplast chambers (19%) remained constant in 2018–2019, unlike Kova chamber users (20%), which reduced. The mean (range) bias of improved Neubauer haemocytometers (–2.8% [–22.5 to +32.0%]) was less than Makler® chambers (+17.0% [–2.9 to +41.2%]), Kova chambers (+33.9% [0.0 to 115.0%]) and Vetriplast chambers (+47.9% [0.0 to 170.0%]). The coefficient of variation of improved Neubauer haemocytometers (14.6% [8.7 to 25.0%]) was less than both Vetriplast (20.7% [8.8 to 36.4%]) and Makler® (24.1% [13.6 to 48.6%]) and Kova chambers (35.5% [15.9 to 123.0%]).

Conclusions

The improved Neubauer haemocytometer has been shown to be superior in accuracy and precision to the Makler®, Kova and Vetriplast chambers in their estimation of concentrations up to 20 × 10⁶/ml. Users of Makler® chambers, specifically designed for counting spermatozoa, should take care to monitor the performance of their own chambers, whereas Kova and Vetriplast chambers (designed for microscopic urinalysis) should not be used.

中文翻译：

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测量精子浓度的四个腔室的性能：来自外部质量保证计划的结果。

研究问题

参加澳大利亚外部质量保证计划的实验室使用四种类型的计数室有何变化，它们的准确性和精密度如何？

设计

在 12 年的时间里，已知浓度高达 20 × 10 ⁶ /ml的乳胶珠样品每季度分发给注册实验室。然后使用每个分布的结果来计算相对于目标值的偏差，作为准确度的指标和变异系数以指示精确度。

结果

2007-2008 年，使用改进的 Neubauer 血细胞计数器（44%）、Makler®（9%）和 Vetriplast 腔室（19%）的实验室比例在 2018-2019 年保持不变，而 Kova 腔室用户（20%）则有所下降。改进的 Neubauer 血细胞计数器的平均（范围）偏差（–2.8% [–22.5 至 +32.0%]）小于 Makler® 腔室（+17.0% [–2.9 至 +41.2%]）、Kova 腔室（+33.9% [ 0.0 至 115.0%]）和 Vetriplast 腔室（+47.9% [0.0 至 170.0%]）。改进的 Neubauer 血细胞计数器（14.6% [8.7 至 25.0%]）的变异系数小于 Vetriplast（20.7% [8.8 至 36.4%]）和 Makler®（24.1% [13.6 至 48.6%]）和 Kova 室（ 35.5% [15.9 至 123.0%]）。

结论

已证明改进的 Neubauer 血细胞计数器在估计高达 20 × 10 ⁶ /ml的浓度时在准确度和精确度方面优于 Makler®、Kova 和 Vetriplast 室。专为精子计数而设计的 Makler® 腔室的用户应注意监测自己腔室的性能，而不应使用 Kova 和 Vetriplast 腔室（专为显微尿液分析而设计）。