Estimating the height of elderly nursing home residents: Which equation to use?

Estimating equations can be used when measuring the height of elderly persons is not possible. However, such methods are not always applicable; therefore, it is necessary to consider several aspects, such as sex, age, and ethnicity of the studied population to generate these equations. This study aimed to compare and validate methods of estimating the height of the Brazilian elderly nursing home residents. An accuracy study was conducted with 168 elderly persons. A total of 23 equations were quantitatively evaluated by plotting the differences in means, the Student's t-test for paired samples, the coefficient of determination (R2), the root-mean-square error (RMSE), the interclass correlation coefficient (ICC), and by graphic analysis of the residuals. A significance value of p <0.05 was adopted. An equation was considered applicable when it had R2 >0.7, the lowest RMSE among the equations evaluated, ICC >0.7, and a confidence interval of 95%, with the smallest difference between the upper and lower limits. A greater mean height was noted among younger elderly persons and elderly men compared to up to 80 years and women elderly. Quantitative analysis revealed that equation for Puerto Ricans, using knee height and age, was the most applicable for the overall population (ICC = 0.802). The same equation was applicable for the elderly Brazilian male participants (ICC = 0.838) and for those aged 60-69 years (ICC = 0.895). None of the equations used were applicable for the height estimation of elderly women or individuals aged 70 years or more.