Objective: This study aimed to investigate the concurrent validity of the block method as compared with the gold standard (Cobb's method). An additional aim was to examine the intra- and inter-rater reliability of expert and novice assessors using the block method.
Methods: In a cross-sectional study, we enrolled 62 participants with hyperkyphosis aged ≥10 years, with hyperkyphosis defined as one or more blocks. The participants were stratified by age (<60 years and ≥60 years). To determine concurrent validity, and kyphosis was assessed in all the participants using the block method and Cobb's method. Finally, 15 participants were included in a reliability study. To determine intra- and inter-rater reliability, each participant was assessed twice, 7 days apart, by one expert and one novice using the block method.
Results: The concurrent validity of the block method and gold standard method showed moderate correlation (rs = 0.53, P < .001). However, after stratifying the participants by age (<60 years and ≥60 years), there was small to moderate correlation (rs = 0.42, P = .006, and rs = 0.64, P = .002, respectively). The intra- and inter-rater reliability of the expert and novice assessors was excellent (ICC3,1 = 0.82-0.97, P < .001).
Conclusions: The findings showed small correlation in those <60 and moderate correlation in those ≥60 years, and reported excellent reliability. The block method can be used by novices with strong reliability. This method is a practical technique for early screening hyperkyphosis in the elderly.
Keywords: Hyperkyphosis; block method; postural deformity; reliability; validity.