Curso e prognóstico da dor lombar aguda em idosos: estudo de coorte prospectivo Back Complaints in the Elders - BACE Brasil

Abstract

Low back pain (LBP) is one of the main causes of physical disability, affecting functioning, autonomy and independence of the elderly population. It is a common and frequent complaint among older adults, for one in four Brazilian elderly is affected by an episode of LBP. However, there are only few studies investigating LBP and aging. The aim of this study was to investigate the course and prognosis of acute LBP on an inception cohort of older adults during a 12-months longitudinal study. Methods: This prospective cohort study is part of the international consortium of epidemiological studies - Back Complaints in the Elders (BACE). Older adults with a new episode of acute LBP were assessed at baseline, 6-week and at 3, 6, 9 and 12 months of follow-up. We excluded participants with cognitive impairment and severe mobility impairments that will limited the realization of assessment procedures. The Numeric Rating Scale (NRS) and the Roland Morris Disability Questionnaire (RMDQ) measured the outcomes pain intensity and LBP related disability, respectively. The Global Perceived Effect (GPE) measured LBP chronicity (non-recovery) three months after baseline assessment. Biopsychosocial factors including clinical, functional, health status, psychological, social variables were evaluated by a multidimensional and structured questionnaire and physical examination. We analyzed data by conducting descriptive statistics, multiple linear regression, logistic regression and latent class analysis, significance level set at 0.05. Results: Total sample consisted of 602 older adults with a new episode of acute LBP aged 67.7 (± 7.0) years, mean pain intensity of 7.2 (± 2.5) in NRS and mean disability of 13.7 (± 2 5) in RMDQ. The majority of the sample consisted of women (84.9%), with low levels of education (62.5%) and low levels of physical activity (61.8%). Worse physical and mental health, low self-efficacy for falls, difficulty in sleeping due to pain, worse levels of kinesiophobia, higher body mass index, presence of morning stiffness in the lower back, more intense pain, being female and having worse functional mobility were significantly associated with disability (p <0.05). These factors combined explained 62% of its variability. Painful hypersensitivity of the lower back, performing imaging examinations for lumbar spine, difficulty sleeping due to pain, expectation of non-recovery, having worse mental health status, perception of income poor and low levels of physical activity were negative predictors for chronicity for the acute episode of LBP. LBP course demonstrated a significant yet discreet reduction in mean pain (20.8%) and disability (12.4%) scores at 3 months. Later, these reductions were slower and less significant, reaching 27.2% and 16.2% at 12 months, respectively for pain and disability. However latent class analysis identified marked reductions in specific subgroups of participants, and more than 50% of participants of the present study showed reductions in pain and disability that were superior to 49% and 30%, respectively. The results showed three different trajectories for course of pain and 4 trajectories for the course of disability over time. Conclusion: Chronicity and LBP related disability were associated with biopsychosocial factors of negative slant to health in older adults. Our findings reinforce the theory of the complex and multidimensional nature of the LBP phenomenon. The course of acute LBP varied in subgroups of older adults with differences in biopsychosocial characteristics. Analyze the course of LBP looking into different trajectories seems to be more appropriate in light of the complexity of LBP complaints. This variability should be considered for proposing specific actions for care of LBP in the elderly population.