The objective of the study was to evaluate the reliability of a manual
assessment of cervical diameter through palpation. In an in vivo trial, 64
Holstein-Friesian cows between 2 and 5d in milk (DIM) and between 21 and 27
DIM were examined by transrectal palpation by 3 investigators. For calculation
of sensitivity and specificity, ultrasound-generated measurements were used as
reference standard; a cervix >7.5 cm was categorized as large. The Pearson
coefficient of correlation between the results of the 3 investigators and
ultrasound-generated measurements was moderate (r=0.71, 0.74, and 0.51). The
estimates generated by palpation by the 3 different investigators did not
differ and were similar to measurements obtained by ultrasound. The
coefficient of variation (CV) between the investigators and ultrasound was
high (20.9, 18.7, and 32.0%). The mean difference between the investigators
and the ultrasound was 0.60 cm (95% confidence interval: -2.4 to 3.6).
Sensitivity was 28.6, 42.9, and 42.9%, and specificity was 100, 96.2, and
92.6% for the ability of the 3 investigators, respectively, to detect the
7.5-cm cutoff by palpation. Overall sensitivity and specificity for all 3
investigators, considering ultrasound as the reference, were 37.5 and 96.2%,
respectively. In vitro, 24 wooden cylinders were used to represent cervical
diameter and to examine the reliability, as well as sensitivity and
specificity, of manual assessment of different diameters. The Pearson
coefficient of correlation between the results of the investigators (n=11) and
the actual diameters of the cylinders was 0.78. The CV between the
investigators and the cylinders was 27.8%. The variation in the results was
greater for cylinders with a larger diameter (3.5-cm diameter: mean ± standard
deviation = 2.6 ± 0.9 cm; 10.5-cm diameter: mean ± standard deviation = 13.2 ±
4.0 cm). The estimate obtained by palpation for the 7.5-cm cylinder was 7.4 ±
2.1cm. Sensitivity was 79.4% and specificity 92.5%. After training one group
of investigators, sensitivity and specificity improved to 85.9 and 94.4%,
respectively. Transrectal palpation of the cervical diameter shows moderate
repeatability and correlation and high variation between the investigators and
the reference standards. Variability increased with larger diameters