A validation study of the Australian Maternity Care Classification System

The Maternity Care Classification System is a novel system developed in Australia to classify models of maternity care based on their characteristics. It will enable large-scale evaluations of maternal and perinatal outcomes under different models of care independently of the model's name.

To assess the accuracy, repeatability and reproducibility of the Maternity Care Classification System.

All 70 public maternity services in New South Wales, Australia, were invited to classify three randomly allocated model case-studies using a web-based survey tool and repeat their classifications 4-6 weeks later. Accuracy of classifications was assessed against the correct values for the case-studies; repeatability (intra-rater reliability) was analysed by percent agreement and McNemar's test between the same participants in both surveys; and reproducibility (inter-rater reliability) was assessed by percent agreement amongst raters of the same case-study combined with Krippendorff's alpha coefficient for a subset of characteristics.

The accuracy of the Maternity Care Classification System was high with 90.8% of responses correctly classified; was repeatable, with no statistically significant change in the responses between the two survey instances (mean agreement 91.5%, p>0.05 for all but one variable); and was reproducible with a mean percent agreement across 9 characteristics of 83.6% and moderate to substantial agreement as assessed by a Krippendorff's alpha coefficient of 0.4-0.8.

The results indicate the Maternity Care Classification System is a valid system for classifying models of care in Australia, and will enable the legitimate evaluation of outcomes by different models of care.