Comparison of three methods for measuring height in rehabilitation inpatients and the impact on body mass index...

To compare standing height, estimated current height and demi-span estimated height and examine their impact on body mass index (BMI) classification.

Cross-sectional data was collected on 104 patients admitted to an adult rehabilitation ward and seen by the dietitian. Patient's standing, estimated current height and demi-span estimated height were collected and grouped by age: 19-64 and ≥65 years.

The limits of agreement (95% confidence interval) for estimated current height compared with standing height were +9.9 cm and -7.9 cm, in contrast to +8.7 cm and -14.3 cm for demi-span estimated height. Demi-span underestimated height when compared with standing height in both age groups, 19-64 years: (mean ± SD) 3.0 ± 6.5 cm (P = 0.001, n = 68) and ≥ 65 year age group 4.0 ± 6.0 cm (P < 0.001, n = 36), resulting in a significantly greater mean BMI (analysis of variance P < 0.001, P = 0.02). In the 19-64 and ≥65 year age groups, 3% (2/68) and 10% (4/36) of patients, respectively, had a different BMI classification using demi-span estimated height compared with standing height.

Estimated current height is a simple and practical alternative if standing height is unable to be obtained when performing a nutrition assessment. Demi-span estimated height should be used with caution when calculating BMI to assess nutritional status, particularly in the elderly.