RELIABILITY OF USING A SMARTPHONE APPLICATION TO OBJECTIFY SKULL DEFORMATION

S. Meijer¹, I. Suir², F. Maissan², J. Nuysink²

Background: Skull deformation in infants occurs as a result of prenatal and/or postnatal forces on the growing skull. The potential interference with motor development is why these infants are often seen by paediatric physiotherapists (PPTs), and warrants a fast and efficient way to objectify the degree of skull deformation. For this reason a new smartphone application, Skully Care App, has been developed. This app is developed for PPTs, and it might be an accessible and easy to use application for other professionals and/or parents.

Purpose: To establish intrarater and interrater reliability of a new developed smartphone app to determine the severity of infantile skull deformation by taking a cranial photo of an infant’s head.

Methods: Measurements were performed during three days at two private paediatric physiotherapy practices in 30 infants aged 1-12 months, who were all treated at the time for any asymmetric or delayed motor development. Three PPTs each took three photos of every infant. For intrarater reliability, all three photos were included in the analyses. For interrater reliability, only the best of three photos was included, according to the opinion of the PPT based on the quality of the photo. The Skully Care app calculates two clinical indices from a photo of the cranial side of the skull: the Cranial Vault Asymmetry Index (CVAI) and the Cranial Index (CI).
Data regarding intrarater and interrater reliability were analyzed with intraclass correlation coefficients (ICC), the standard error of measurement (SEM) and the smallest detectable difference (SDD).

Results: The intrarater reliability showed to be excellent both for CVAI and CI, with an ICC(3,1)= 0.97 (95% CI 0.95-0.98) and ICC(3,1) = 0.98 (95% CI 0.97-0.98) respectively. The SEM(agreement) for the CVAI was 0.55 and 0.90 for the CI. The SDD(agreement) was calculated and came to a value of 2.06 for the CVAI and 2.63 for the CI.
Also the interrater reliability with an ICC(2,1)= 0.97 (95% CI: 0.95 – 0.99) for the CVAI and ICC(2,1)= 0.99 (95% CI: 0.98 – 0.99) for the CI was excellent. The SEM(agreement) was 0.41 for the CVAI and 0.69 for the CI. The SDD(agreement) was 1.13 for the CVAI and 1.90 for the CI.

Conclusion(s): The reliability of the app Skully Care proved to be excellent when used by PPTs, even after limited training. In a following stage of the research, this study can be completed with a test-retest research in varying circumstances. In addition, it will be relevant to investigate the usability of the app for other professionals and parents.  

Implications: The Skully Care app is a time-saving and easy-to-use app for PPTs to objectify skull deformation. Professionals and parents can be informed quickly, in order to start treatment in time, if necessary. Parents’ understanding on skull deformation will grow, which motivates them to apply  posture and handling advices.

Funding, acknowledgements: This study received no funding.

Keywords: Infant, skull deformation, smartphone application

Topic: Paediatrics

Did this work require ethics approval? No

Institution: HU University of Applied Sciences

Committee: Medical Ethical Screening Committee (HU University of Applied Sciences)

Reason: The study did not impose any additional burden on the child and parents, and included informed consent procedure.