Larry Hand
March 24, 2014
Low back pain (LBP) causes more disability globally than any other condition, according to 2 studies published onlineJanuary 30 and March 24 in the Annals of the Rheumatic Diseases. As the world population continues to age, an urgent need exists for research to find out why and how LBP might be prevented or better managed, researchers write.
Damian Hoy, MPH, from the University of Queensland School of Population Health, Australia, and colleagues conducted systematic reviews of the prevalence, incidence, remission, duration, and mortality risk for LBP. Their research was conducted as part of the Global Burden of Disease 2010 Study(GBD).
The researchers included 2566 data points from 170 published studies representing 85 countries and 20 of the 21 GBD 2010 world regions in their analysis. Of 291 conditions studied in GBD 2010, LBP, defined as pain that lasts a day or longer and may or may not extend into 1 or both legs, ranked highest in years lived with disability.
The researchers calculate the global age-standardized prevalence of LBP in 2010 at 9.4% (95% confidence interval [CI], 9.0% – 9.8%), with no significant change from 1990. Men had a higher prevalence (mean, 10.1%, 95% CI, 9.4% – 10.7%) than women (mean, 8.7%, 95% CI, 8.2% – 9.3%).
Western Europe had the highest prevalence (mean, 15.0%; 95% CI, 14.1% – 16.0%), followed by North Africa/Middle East (mean, 14.8%; 95% CI, 13.8% – 15.9%). The Caribbean had the lowest prevalence (mean, 6.5%, 95% CI, 5.6% – 7.4%). High-income regions of North America had a relatively low prevalence, at 7.7% for men and women (95% CI for men, 6.2% – 9.4%; 95% CI for women, 6.1% – 9.5%).
LBP also ranked sixth in disability-adjusted life years (DALYs), which increased from 58.2 million in 1990 to 83.0 million in 2010. “Population increase contributed 30% of the 43% increase in DALYs between 1990 and 2010 while ageing was responsible for the remaining 13%,” the researchers write.
High Prevalence Worldwide
“The process for estimating the global burden of LBP has been extensive, and has taken almost 6 years,” they continue. “The results show that the prevalence and burden from LBP is very high throughout the world.”
A strength of the study, researchers write, included improvements between 1990 and 2010 in defining LBP cases and use of more advanced models. Limitations include considerable methodological variation among studies analyzed in the systematic review.
“There is a clear need for further research on the natural history of LBP,” the researchers write. “With expanding and ageing populations in many low-income and middle-income countries, the enormous burden from LBP in these areas will grow significantly over coming decades. There is an urgent need to increase our understanding, and attempt to mitigate the growing burden of LBP in these areas.”
Occupation-Related LBP
In an accompanying article, Tim Driscoll, BSc, from the Sydney School of Public Health, University of Sydney, Australia, and colleagues analyzed data from the International Labour Organization Labour Force database to calculate how occupational exposure affect the incidence of LBP. The database contains 8849 data points for 133 of the 187 GBD 2010 countries.
Occupational risk factors for LBP include rapid pace and repetitive nature of work tasks, heavy lifting, bending and twisting, strained postures, and inadequate recovery time between exposures.
The researchers found that the number of occupation-related DALYs increased 22% overall between 1990 and 2010 because of population growth, but the rate of occupation-related DALYs decreased by 14%.
They calculated a total of 21.8 million work-related DALYs in 2010 (95% uncertainty interval, 14.5 – 30.5 million). Of these, men accounted for 13.5 million (61.9%) and women accounted for the remaining 8.3 million.
The greatest burdens for work-related LBP were being aged between 35 and 65 years, being in the agriculture sector of the economy, and living in regions with high populations, including Asia and North Africa/Middle East.
“This study has shown that LBP arising from occupationally related ergonomic exposures is an important cause of disability in working persons,” the researchers write. “Focus on interventions to reduce exposure to the causative ergonomic risk factors, and work to improve the available exposure and risk information, especially in developing countries, would be appropriate responses to these findings.”
For the Hoy article, research was supported by the Bill and Melinda Gates Foundation, the Australian Commonwealth Department of Health and Ageing, the Australian National Health and Medical Research Council, Practitioner Fellowships, and the Ageing and Alzheimer’s Research Foundation. Dr. Hoy and the other authors have disclosed no relevant financial relationships. For the Driscoll article, Dr. Driscoll has reported receiving partial funding from the Australian National Occupational Health and Safety Commission (Safework Australia). The other authors have disclosed no relevant financial relationships.
Ann Rheum Dis. Published online January 30 and March 24, 2014. Hoy abstract, Driscoll abstract