Trajectories of Physical Function and Disability Over 12 Months in Older Adults With Chronic Low Back Pain.

The sample was community-dwelling, not care-seeking, and lacked racial diversity while being generally well-educated, so it may not apply to all older adults with chronic low back pain. All outcomes were self-reported questionnaires, not performance-based tests, so reported function and disability may not match observed function. The physical function worsening class had only 5 people, so that subgroup is small and could be influenced by other health events such as hospitalization or worsening knee pain. Five participants who had low back surgery during follow-up were excluded, so the results do not describe trajectories after surgery. The study described classes that emerged from the data and did not test an intervention, so it cannot show that changing steps, pain, fear, catastrophizing, mood or comorbidity will change a person's course. The authors state that replication in a larger sample is required.

Do not read the step-count and pain differences as proof that changing those factors will improve prognosis. The study observed baseline characteristics alongside trajectory classes; it did not test whether changing them changes outcomes.