More than 6m people worldwide live with low back pain – with women more than men being affected – but research shows that tacking the major risk factors like smoking, obesity and workplace ergonomics, could curb the trend, write Jaimie Steinmetz and Manuela Ferreira in The Conversation.
Low back pain is the leading cause of disability in the world, according to a recent systematic international analysis that synthesised data from 500 global studies to estimate the global burden of low back pain, broken down by country, year, age, sex and severity.
The scientists measured low back pain from five-year-olds onwards, and found it has ranked first among causes of disability for the three decades.
Back pain, however, is not inevitable, even if that sometimes feels like the case, they said.
Their findings are part of a larger project called the Global Burden of Disease Study, which aims to quantify all health loss globally.
The study found that if society could directly address three major risk factors – obesity, smoking and workplace ergonomic factors – it could slash the burden of low back pain by 39%.
Smoking has been previously associated with damaged microcirculation of the spinal structures, for example, the discs and joints, as well as weakening of the bones. But researchers also know that smoking is often linked other lifestyle factors, including physical inactivity, obesity and poor sleep, all of which have been tied to an increased risk of low back pain.
Similarly, obesity is associated with other unhealthy lifestyle factors, all of which can increase the risk of low back pain. Obesity is also linked to an increased load on the spinal structures, predisposing them to injury, and a systemic inflammatory response.
Why it matters
Low back pain is influenced by many factors, including biological, social and psychological. The anatomical complexity of the human spine means that in most cases, a simple structural cause such as a single joint or muscle cannot be identified, even with sophisticated diagnostic imaging.
This means diagnoses are made largely on the basis of reported symptoms. And whereas most cases are short-lived, with recovery experienced within the first six weeks of pain onset, one-third of cases will become persistent and may last for years. This persistence contributes to the significant burden of this condition.
As part of this work, the scientists estimated how many people are likely to experience low back pain over the next 30 years if little changes – and predicted that a whopping 843m people around the world will be living with the condition.
They said the problem won’t go away unless policymakers intervene.
Although a person’s sex does not directly determine the risk of low back pain, the condition is much more common among females, the study finding a global total of 395m women reporting back pain compared 225m males.
This discrepancy could be explained by differences in care-seeking behaviour, as well as in access to health care, between men and women.
The rates of occurrence also differ depending on age. It is a common myth that low back pain is most common in working-age adults, but in fact, rates are highest for people in their 80s. Older adults often are overlooked when it comes to care.
Older adults with low back pain have limited access to evidence-based treatments that encourage a healthy lifestyle and recovery, such as those that support patients to manage their own symptoms.
They are also less likely to recover from severe pain and disability than their younger counterparts, are more prone to develop long-term, persistent symptoms, and are at an increased risk of falls.
What still isn’t known
Better and more effective ways are needed to manage this pain. Studies show many current treatments either don’t work or do very little. These treatments include pain relievers and some surgical procedures.
It’s clear, said the study authors, that more research is needed to identify effective preventive strategies.
Study details
Global, regional, and national burden of low back pain, 1990–2020, its attributable risk factors, and projections to 2050: a a systematic analysis of the Global Burden of Disease Study 2021
GBD 2021 Low Back Pain Collaborators
Published in The Lancet Rheumatology in June 2023
Summary
Background
Low back pain is highly prevalent and the main cause of years lived with disability (YLDs). We present the most up-to-date global, regional, and national data on prevalence and YLDs for low back pain from the Global Burden of Diseases, Injuries, and Risk Factors Study 2021.
Methods
Population-based studies from 1980 to 2019 identified in a systematic review, international surveys, US medical claims data, and dataset contributions by collaborators were used to estimate the prevalence and YLDs for low back pain from 1990 to 2020, for 204 countries and territories. Low back pain was defined as pain between the 12th ribs and the gluteal folds that lasted a day or more; input data using alternative definitions were adjusted in a network meta-regression analysis. Nested Bayesian meta-regression models were used to estimate prevalence and YLDs by age, sex, year, and location. Prevalence was projected to 2050 by running a regression on prevalence rates using Socio-demographic Index as a predictor, then multiplying them by projected population estimates.
Findings
In 2020, low back pain affected 619m (95% uncertainty interval 554–694) people globally, with a projection of 843 million (759–933) prevalent cases by 2050. In 2020, the global age-standardised rate of YLDs was 832 per 100 000 (578–1070). Between 1990 and 2020, age-standardised rates of prevalence and YLDs decreased by 10·4% (10·9–10·0) and 10·5% (11·1–10·0), respectively. A total of 38·8% (28·7–47·0) of YLDs were attributed to occupational factors, smoking, and high BMI.
Interpretation
Low back pain remains the leading cause of YLDs globally, and in 2020, there were more than half a billion prevalent cases of low back pain worldwide. While age-standardised rates have decreased modestly over the past three decades, it is projected that globally in 2050, more than 800 million people will have low back pain. Challenges persist in obtaining primary country-level data on low back pain, and there is an urgent need for more high-quality, primary, country-level data on both prevalence and severity distributions to improve accuracy and monitor change.
Jaimie Steinmetz is lead research scientist in Population Health, Institute for Health Metrics and Evaluation, University of Washington;
Manuela Ferreira is professor of Musculoskeletal Health, University of Sydney.
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