Limitations
Only three of the reviewed studies were rated with a high level of
evidence based on rigorous experimental prospective RCT designs that
included power analysis. Although kyphosis and QOL may track along the
same direction (correlation), a causal inference cannot be made without
a true experimental controlled study. The reviewed studies did not
include equal representation of the sex demographic variable (i.e.,
recruited participants were primarily female) or pediatric oncology
patients. Perhaps the underlying pathophysiology of osteoporosis or
scoliosis affected the kyphosis in a different way than cancer would.
Furthermore, characteristics of the study populations including previous
life experiences were not well defined, which could impact their
baseline QOL and/or posture status. Inconsistency in utilized posture
and QOL measures make the findings less generalizable. Finally, we did
not find evidence that posture is a more sensitive and precise measure
of QOL than existing self-report or proxy-report questionnaires, so it
fits better as a physical sign to augment QOL measurement than a
surrogate biomarker.14