Assessing the accuracy and reliability of direct height measurement for use in adult neurological patients with contractures: a comparison with height from ulna length

Abstract

It is not possible to measure the height of a patient with contractures in the normal way. On occasions, health professionals need to measure the height directly of patients with contractures because: (i) the patient is unable to report his/her height as a result of a lack of mental capacity and (ii) there is no-one available to report the height or the reported height is obviously inaccurate. Height derived from ulna length is an option but, in some individuals, it can be conspicuously inaccurate. Therefore, we have attempted to develop and validate a simple bedside method using a tape measure. Twenty-four normal healthy adult volunteers were recruited into the study. They were positioned on a hospital bed in three different standardised positions simulating patients with typical contractures. They were measured in each position by four measurers using blanked out tape measures. The participants were then measured standing giving a 'true' height. Ulna length was also measured. The mean of the tape-measured heights was 2.3cm taller than the 'true' height (95% confidence interval=4.6-9.3). The measurement in all three positions gave an over-estimate of the height, whereas the ulna-derived height gave an under-estimate (2.2cm). The estimated reliability between measurers (intraclass correlation coefficient) was 0.94 with a 95% confidence interval (0.91-0.96). This new method is giving an acceptable estimate of the height of contracted patients with a good inter-rater reliability. It comprises a useful additional tool for measuring the height of people with contractures.