Prognosis in nonspecific low back pain

Costa-Black, 2010Foster, 2014Hayden, 2009Hayden, 2010Hill, 2008Hill, Whitehurst, 2011Kamper, 2012Linton, 2003Shiri, 2010Shiri, 2010

Low back pain is designated as acute if it persists for less than 12 weeks or chronic if it persists for longer than 12 weeks. The outcome of a single episode of nonspecific low back pain is generally favourable. Most patients have acute nonspecific low back pain and their symptoms improve rapidly (usually within 4 weeks), with no ongoing limitation in daily activities. Patients can resume normal physical function and return to work quickly regardless of whether the pain has fully resolved. However, many of these patients will have recurrent episodes of low back pain.

A small number of patients develop chronic nonspecific low back pain, which can be severe and disabling. Among those who present with chronic symptoms, two-thirds are still not fully recovered at 1 to 2 years. Therefore, early intervention to address risk factors for chronicity is important in patients with acute low back pain.

Risk factors for poor prognosis include a high level of pain and disability at presentation, leg pain, older age, poor general health, psychosocial factors (eg mental stress, anxiety, depression), and reduced cognition. For work-related prognostic factors, see Prevention of work-related disability in people with nonspecific low back pain. Misconceptions about the nature of the pain and unhelpful coping strategies can also contribute to poor prognosis; these include:

• belief that back pain is harmful to the spine
• belief that there is structural damage to the spine associated with spinal weakness or instability
• fear-avoidance behaviour and reduced activity and participation
• lowered mood and withdrawal from social interaction
• belief that passive treatment(s) alone rather than active participation will help.

There are several tools that have been developed to aid in the assessment of risk factors for poor prognosis, such as the StarT Back tool, Örebro Musculoskeletal Pain Questionnaire and the PICKUP toolLinton, 2003Traeger, 2015. These aim to help to avoid unnecessary overtreatment in patients with a good prognosis and direct more intensive care to those who are at high risk of a poorer outcome. However, these may not add substantively to an experienced clinician’s assessment, and it is important to consider any potential consequences (undertreatment or overtreatment) that may arise from misclassification when using one of the above toolsKarran, 2017. Depending on the duration of symptoms at the time of presentation, some risk factors for poor prognosis may not be assessable initially.