This study highlights the high prevalence and burden of LBP in Brazil. We found that LBP prevalence increased by 26.82% (95% UI 23.08 to 30.41) between 1990 and 2017 and tends to be higher among southern and southeastern Brazilian states. However, it appears to be increasing more between northern, northeastern, and midwestern federative units in the last 27 years. LBP represents the most important cause of YLDs in Brazil, remaining in the first place of rankings of YLDs for GBD diseases in this 27-year period. Although the increase in this burden is mainly related to increases in population size and aging. As with prevalence, GBD also estimated higher rates of YLDs for the southern and southeastern states, but the increase in the period 1990-2017 is similar in almost all states, except for Rio de Janeiro that had a decrease. Brazilian age-standardized YLDs rates are similar between states and higher than global estimates. LBP is a disease that does not lead to death. Hence, it does not contribute to years of life lost (YLL), and 100% of all LBP DALYs are due to YLDs. The chronicity of LBP and the fact that it begins at younger ages causes the burden for LBP to rank in the top three causes of DALYs in Brazil.
The Brazilian National Health Survey (PNS) 2013 found a prevalence of back pain of 18.5% in persons 18 years or older, higher than GBD estimates [12]. The PNS evaluated chronic pain with the question: “Do you have a chronic back problem, such as chronic back or neck pain, LBP, sciatica, vertebrae or disc problems?” but did not delimit the period of the pain occurrence, while the GBD assessed prevalence in last year (at least 1 day in last 12 months) only for LBP [12]. This difference in classifications could in part explain the differences between GBD prevalence estimates and PNS. Furthermore, results from the PNS were not included in the data selection process used to generate GBD estimates; that is, the real values may be even larger, which only reinforces the magnitude of the problem.
Although in this study the prevalence rate of LBP seems to be higher among women, there was no statistically significant difference in relation to men’s rates. A higher prevalence of LBP in women has been observed in some previous studies [12, 30]. In the literature, this has been attributed to the greater awareness of women about the symptoms and signs of diseases [14, 31]; factors such as performing housework in greater intensity in non-ergonomic position and repetitive tasks [31]; differences in anatomical and functional characteristics, such as smaller height, less muscle mass, less bone mass, joints more fragile, and less adapted to strenuous physical effort, may result in more overload in the back [31]; pregnancy factors, like hormones, weight increase, inadequate posture during pregnancy, postural inadequacies when breastfeeding, the child’s weight, and other factors [31].
Age is one of the most common risk factors for MSK conditions. The ratio of older to younger people will continue to increase throughout the world. Additionally, the number of people who are obese, which is now one of the major risk factors for MSK conditions, is expected to increase more dramatically in low-income and middle-income countries over the coming two decades [8]. Data from a Brazilian national survey shows that factors associated with a higher prevalence of chronic back pain in both sexes, adjusted by age and education, were increasing age; low education level; smoking history; high salt intake; heavy activity at work or at home, and the increase in the time spent on these activities; being overweight or obese; having chronic diseases; and poor health assessments [12]. The main risk factors for LBP according to the GBD study are occupational ergonomic factors, smoking, and high body mass index [26].
LBP is the largest cause of MSK disability in Brazil [6] and a large proportion of those affected are in their most productive years of life. This can have a major effect on a family’s livelihood as the ability to be productive in these years is often required to support younger and older family members [3]. Chronic back pain is one of the most commonly reported complaints by the adult population, causing disability, reduced functionality, absence from work, and the most common cause of social security pension disability claims and early retirements in Brazil [13]. In addition to indirect costs, related to lower productivity, time away from work, and expenses resulting from sick leaves and early retirements, the direct costs are quite significant—tests, medications, physical therapy, and hospitalizations [31]. Between 1995 and 2014, expenditure on spinal surgery in Brazil increased by 540% (from R$27.1 million to R$146.5 million) [8]. Nevertheless, few studies exist for these disabling health conditions.
Progress in reducing the impact of disabling conditions has been much slower—the focus remains on reducing mortality rather than the main causes of disability. The slower progress in addressing non-fatal compared with fatal health outcomes and aging of populations make YLDs an increasingly important component of global DALYs. In some countries with advanced aging, YLDs already make up more than half of the total burden in DALYs [6].
The growing number of people affected by MSK conditions in low- and middle-income countries, including Brazil, is of great concern. Health services are not prepared to meet such demand. A paradigm shift is urgently needed if we are to alleviate the increasing global burden of non-fatal diseases, such as MSK conditions, and reduce the number of avoidable disabilities [3].
Our findings call for the integration of prevention and control programs for MSK disorders within health system programs, which may reduce the severity of disabilities. Interventions should include control of known risk factors especially through health education and awareness; ergonomic factors in occupational health and safety assessments; provide evidence-based early diagnosis and treatment; rehabilitative care and community programs to increase knowledge of relevant risk and protective factors.
A recent meta-analysis of population-based interventions to prevent LBP concluded that combined strengthening with stretching or aerobic exercises two to three times per week can be recommended to prevent LBP [32]. Greater exercise appears to prevent incident episodes of LBP, and the effect may be greater when exercise is combined with self-care education [33]. Greater effort by the Brazilian National Health System (SUS: Sistema Único de Saúde) and private health systems to stimulate the regular practice of physical activity and stretching should be pursued. The relative lack of studies on the prevention and management of this condition also calls for a greater priority in research funding for investigation of the prevention and management of LBP. In addition, it is necessary to improve the collection of health data to monitor trends and efficacy of interventions.
There are inherent limitations in estimating LBP, because their measurement is fully dependent on self-reported metrics and the recognition of the disease by the individual depends on the degree of perception, frequency of signs and symptoms. To mitigate this, the GBD 2017 study makes adjustments for variations in recall period, anatomical location, minimum duration of episodes, and the extent to which the condition limits activity. Also, there are limitations inherent to the GBD process estimation. One of them is the absence of studies about LBP prevalence in all Brazilian states. Rio Grande do Sul was the state which presented the highest rates for prevalence and YLDs for LBP, and also was the one with the largest number of studies. It is possible that estimates may be under assessed in other states. To mitigate this other limitation, GBD uses complex modeling to get closer to real estimates.