Is the occiput-wall distance valid and reliable to determine the presence of thoracic hyperkyphosis?

BACKGROUND

Hyperkyphosis may be frequently found nowadays due to the change in current lifestyles of sustained flexion postures and age-related system decline. The occiput-wall distance (OWD) is a practical measure that is commonly used to screen and monitor thoracic hyperkyphosis in epidemiologic studies. However, there was no clear evidence to support the clinical utility of the tool as compared to the data from direct standard measures.

OBJECTIVES

To investigate psychometric properties-including validity, reliability, and appropriate cut-off point-of the OWD to determine the presence of thoracic hyperkyphosis, as compared to a standard Cobb's method.

DESIGN

Observational study.

METHODS

This study was conducted in ninety-nine participants, aged 10 years and above who had different degrees of thoracic hyperkyphosis from several communities. All participants were assessed for their severity of thoracic hyperkyphosis using the OWD, and 14 participants were involved in a reliability study. Within 7 days later, all participants were at a hospital to complete a radiographic examination.

RESULTS

Outcomes from OWD had good concurrent validity with the Cobb angles (r = 0.683, P < 0.001) and excellent rater reliability when assessed by well-trained health professionals (ICCs > 0.9, P < 0.001). The OWD of at least 6.5 cm had the best diagnostic properties to determine the presence of thoracic hyperkyphosis (sensitivity = 71.4%, specificity = 76.6%, and area under the curve = 0.846).

CONCLUSION

The findings support validity and reliability of OWD, and offer a clear cut-off point to determine the presence of thoracic hyperkyphosis for clinical utility in various settings.