Examining laboratory accuracy and precision of 'cervical dilatometer, in measuring cervical dilatation

Abstract

Objective: To assess laboratory accuracy and precision of 'cervical dilatometer' in measuring cervical dilatation. Methods: Seven midwives in two groups of experimental phases were asked to measure cervix dilatation blindly in artificial simulators ranging from 40 to 100 mm by means of the device. Results were recorded and then after using a simple calculation, dilatations were reported. For the accuracy and precision of the instrument ICC (Inter-Class Correlation) between simulators and examiners reports, ICC between observers, Pearson's Correlation and Standard Error, all with 95% confidence interval, were used. Ninety-five examinations in 37 simulators were performed, none of the cases excluded. Results: According to the statistical analyses there were positive correlations between the instrument reports and simulators real sizes in either phases (ICC=0.968 in phase 1 and 0.834 in phase 2). Reliability of the instrument using Cronbach's Alpha was 0.995, inter-observer agreement due to ICC and Pearson's correlation was 0.995 and 0.697 in phase 1 and phase 2 respectively. Conclusion: Cervical Dilatometer qualifies accuracy, precision and reliability requirements to be used as a cervimetry instrument in laboratory phase. Further research is needed to determine those elements in clinical set-up.