The recovery patterns of back pain among workers with compensated occupational back injuries

Abstract

Objectives: To investigate the longitudinal patterns of recovery among workers with compensated occupational back injuries. Methods: A longitudinal cohort study, with one-year follow-up via structured telephone interviews, among respondents off work because of ''new'' back injuries. Self-reported pain intensity was recorded at baseline and at four follow-up time points over the course of one year. Workers who answered the questionnaire on at least three occasions (n = 678) were classified into clusters according to their patterns of pain intensity over time using a two-step cluster analysis. Results: Four pain recovery patterns were identified: workers with high levels of pain intensity showing no improvement over time (43%); those experiencing recovery in the first four months with no further improvement or possibly even some deterioration, in the second half year (33%); those experiencing a slow consistent recovery but still with considerable back pain at the end of the follow-up (12%); and those quickly progressing to low level of pain or resolution (12%). Trajectories of average Roland-Morris Disability scores and SF-36 Role of Physical scores for above clusters mapped consistently with the corresponding patterns in pain. However, individuals with fluctuating, recurrent pain patterns showed the shortest cumulative duration on 100% benefit and the earliest return-to-work among other clusters. Conclusions: Four clinically sensible patterns were identified in this cohort of injured workers, suggesting inter-individual differences in back pain recovery. The results confirm that recurrent or chronic back pain is a typical condition in respondents with new back injuries. Pain intensity and disability scores are good measures of recovery of back pain at the individual level. After initial return-to-work, or cessation of benefits, administrative measures of percentage of respondents back at work, or no longer on benefits, may not accurately reflect an individual's condition of back pain.

Patients with low back pain had distinct clinical course patterns that were typically neither complete recovery nor constant pain. A latent class analysis of longitudinal data

“…Subgroups based on LBP trajectories have previously been identified in studies of six different cohorts [6][7][8][9][10][11]. Five of these used some sort of computerized subgrouping technique [6][7][8][9]11] and described four to five distinct LBP trajectories.…”

“…Five of these used some sort of computerized subgrouping technique [6][7][8][9]11] and described four to five distinct LBP trajectories. Within these studies, substantial differences between the identified subgroups indicate that the traditional use of only a population-averaged clinical trajectory may be limiting, or even distorting, our understanding of LBP.…”

Trajectories of acute low back pain

“…4,8,14 For example, Dunn et al 14 studied 342 patients from primary care with back pain over 1 year using latent class analysis. The method identified 4 clusters that differed across pain status and impact, disability, and psychological characteristics.…”

How is recovery from low back pain measured? A systematic review of the literature

“…For example in some studies the term is used synonymously with global improvement [92], in others with improvement on various indicators such as disability [16] and return to work [69]. There is also a fundamental consideration regarding the meaning of recovery; that being whether recovery requires return to a prior health state or whether attainment of a fulfilling and satisfying life within the limitations of the condition is enough [21,80].…”