Abstract
Introduction
Low back pain (LBP) is well documented to be an extremely common health problem; however, its burden is often considered trivial. 1 LBP is an integral part of most human lives and causes different degrees of suffering and disability. The exact cause of pain cannot be identified in most instances. It is the leading cause of activity limitation and work absence and its causes are enormous economic burden on individuals, families, communities, industry, and governments. 2 This epidemiologic study of LBP investigates how its frequency varies by sociodemographic factors such as age, gender, race, and location.
Recent studies continue to confirm that LBP is a common disorder in Western and developing nations. 3 It has been estimated 4 that more than 80% of the population will report low back pain at some point of life and each year 7% of the adult population consult their general practice with symptoms. In an extensive review of the international literature on the incidence of disabling LBP, Nachemson 5 reported that the problem of LBP was even greater in Canada, Great Britain, the Netherlands, and Sweden in comparison with the United States and Germany. In the United States, back pain is the most common cause of activity limitation in people younger than 45 years, the second most frequent reason for visits to the physician, the fifth ranking cause of admission to hospital, and the third most common cause of surgical procedures. 6 The intercultural differences between nationalities in pain perception or pain reporting may be an explanation for the variation in prevalence rates in countries. It was largely thought of as a problem confined to Western countries, but at the moment, extensive amount of research has demonstrated that LBP is a major problem in low- and middle-income countries as well. 7
In the past, it was documented that LBP is a common complaint in general practice in primary care settings. 8 LBP has a substantial impact on individuals and their families, communities, health care systems, and business. Impacts and outcomes from LBP are likely to vary significantly between and within populations depending on socioeconomic status, general access to health services, occupational distribution, and other factors that are associated with the onset and prognosis of LBP. Sociodemographic factors have great impact on LBP. Bener et al 9 reported in their previous study that LBP can have a substantial negative impact on quality of life. Risk factors of LBP are multifactorial and include physical factors, sociodemographic characteristics, habits, and psychological factors. The present study reviewed the epidemiology of LBP with emphasis on frequency, the influence of age, gender, occupational, educational, social factors, and association of lifestyle habits on LBP.
Subjects and Methods
This is a cross-sectional study and the study included subjects aged 15 to 65 years who attended primary health care centers throughout Qatar. Primary health care centers are frequented by all levels of the general population as a gateway to specialist care. To secure a representative sample of the study population, the sampling plan was stratified with proportional allocation according to stratum size of primary health care clinics. The study was conducted among people, who were visiting 12 health centers; 9 centers from urban areas and 3 centers from semi-urban areas as a representative sample of the community.
The sample size was determined with the prior knowledge that the prevalence of LBP in the State of Qatar is similar to that in a neighboring country. A representative sample of 2742 subjects aged between 15 and 60 years was computed based on a prevalence of LBP in the United Arab Emirates10,11 reported to be 50% to 64% with allowed bound on 2.5% error of estimation and level of significance (type I error) of 5%. Accordingly, 2742 subjects aged between 15 and 60 years were approached and 2180 subjects agreed to take part in this study, thus giving a response rate of 79.5%. Data collection took place from March to October, 2012. Qualified nurses were trained to interview the patients and complete the questionnaires. The survey instrument was pilot tested on 100 patients who visited health centers and thus obtained face validation of the questionnaire. The study excluded patients aged younger than 15 years and older than 65 years, patients with any cognitive or physical impairment, and who refused to give consent to take part in the study.
Patients with current LBP were identified by asking a question, “Thinking back within the past 6 months, have you had any backache or pain in the lower back that lasted 1 day or longer?” In addition, patients with LBP were further examined by the primary health care physician to confirm the location of pain and its characteristics. By definition, LBP is a symptom with no external standard by which its presence can be validated. Additional data were collected through a validated self-administered questionnaire with the help of qualified nurses. The questionnaire included sociodemographic details of the patients, associated factors such as physical lifestyle pattern, triggering factors, and type of treatment taken by patients for relief for data collection. For some participants who were illiterate, the nurses read out the questions to complete the questionnaires.
Approval was obtained from the Hamad Medical Corporation Institutional Review Board for conducting this research in Qatar.
Chi-square analysis was performed to test for differences in proportions of categorical variables between 2 or more groups. In 2 × 2 tables, Fisher’s exact test (2-tailed) replaced the χ2 test if the assumptions underlying χ2 were violated, namely in case of small sample size and where the expected frequency is less than 5 in any of the cells. We used multivariate logistic regression model to determine the predictors of LBP. The level P < .05 was considered as the cutoff value for significance.
Results
Table 1 shows the sociodemographic characteristics of the studied subjects according to gender. Of the subjects studied, 52.9% were males and 47.1% were females. There were significant differences between males and females in terms of nationality (P < .001), body mass index (BMI; P = .001), occupation (P < .001), monthly household income (P < .001), cigarette/sheesha smokers (P < .001), and type of bed mattress being used (P = .006).
Sociodemographic Characteristics of the Participants According to Gender (N = 2180).
Table 2 reveals the sociodemographic characteristics of patients with LBP according to gender. The prevalence of LBP in the study sample was 59.2%. Among the study sample of patients with LBP, women (53.9%) were more likely to present with LBP compared with men (46.1%). Majority of the male and female patients with LBP were in the age-group 45 to 55 years (37.6% and 36.4%, respectively). The figures declined after the age of 55 years (23.7% and 28.5%, respectively). Men (22.5%) and women (24.5%) with educational level of secondary school graduation had higher chance of developing LBP than with those with university degree (19.2% and 21.6%, respectivley). More than half of the women (50.4%) with LBP were housewives, whereas most of the men with LBP had clerical jobs (36.8%). In all, 93.3% of the patients with LBP were married. A significant difference was observed between men and women in terms of BMI (P < .001), nationality (P < .001), marital status (P = .005), and occupation (P < .001).
Sociodemographic Characteristics of the Patients With Low Back Pain According to Gender (N = 1290).
Table 3 examines the prevalence of exacerbating factors on LBP according to gender. The use of sponged mattress was significantly higher among male patients with LBP as compared with females (50.9% vs 45.8%, respectively; P = .041). Significantly higher proportion of males with LBP reported prolonged standing as compared with females with LBP (41.2% vs 29.5%, respectively; P < .001). Exercise and coughing/sneezing/straining were the most common triggering factors among males with LBP as compared with females (18.7% vs 13.2%; P = .024 and 9.7% vs 5.9%; P = .010, respectively). Males reported worsening of LBP in morning (30.2% vs 21.9%; P < .001); on the other hand, among females pain worsened in the evening time (53.4% vs. 44.2%; P = .001).
Prevalence of Exacerbating Factors on Low Back Pain According to Gender (N = 1290).
Multivariable logistic regression analysis for the predictors of LBP (Table 4) reveals that obesity (odds ratio [OR] = 3.26, 95% confidence interval [CI] = 2.50-4.24; P < .001), low monthly income (OR = 1.38, 95% CI = 1.15-1.65; P = .001), being married (OR = 1.6, 95% CI = 1.64-2.35; P = .008), being female (OR = 1.96, 95% CI = 1.64-2.35; P < .001), and smoking (OR = 1.4, 95% CI = 1.11-1.77; P = .003) were the predictors for LBP.
Figure 1 compares the prevalence rate of LBP in the general population of developed and developing countries. The prevalence rate of LBP in Qatar was much higher than the rate observed in developed countries such as Canada (28.7%), the United Kingdom (36.1%), and Sweden (39.2%), and it is very close to rates in Africa (62%) and China (64%).
Comparison in prevalence rate of low back pain in general population of developed and developing countries.
Figure 2 examines the treatment taken by patients with LBP for relief. Most of them had bed rest (45.3%) followed by warm compression (32.2%) and physiotherapy (31.5%).
Treatment taken by studied low back pain patients for relief (n = 1290).
Discussion
Low back pain is a multifactorial disorder with many possible etiologies. The present epidemiologic study of LBP analyzed various risk factors in the general population of Qatar. The study has focused on risk factors for LBP attempting to analyze sociodemographic characteristics and individual and physical factors such as gender, age, nationality, BMI, lifestyle habits, physical strain, heavy lifting, and postural stress. In the study sample, the prevalence of LBP was 59.2%, which is in line with the rates observed in Denmark (56%), 12 Africa (62%), 13 and China (64%). 7 The prevalence rates observed in developed countries such as Australia (25.6%), 14 Canada (28.7%), 15 the United Kingdom (36.1%), 16 and Sweden (39.2%) 17 were reasonably lower than the study prevalence.
It was reported in the United Kingdom 16 that the presence of LBP was associated with sociodemographic factors, such as gender, age, education level, smoking, and occupation. The present study also revealed significant correlations between the frequency of LBP and sociodemographic factors, which is in accordance with earlier observations.7,12,13 Age has been suggested to play a role in the development of LBP. In the study sample, the occurrence of LBP continues to increase with age as patients aged toward the 45- to 55-year range (37%), after which there seems to be a decline (26.3%) after 55 years. Similar results were reported in earlier studies18,19 that LBP increased with age (up to 50- to 60-year range) and decreased gradually thereafter. This shows that age is one of the more common risk factors for LBP and the incidence was highest in the third decade. Also, majority of the patients with LBP were married (93.3%) and the OR revealed that marital status was a significant predictor for LBP (OR = 1.6; P = .008), which is similar to the results of Gatchel et al 20 that LBP was more frequent among married patients (61%) than among divorced or single patients (39%).
Although few studies 20 have found no significant differences in the prevalence of LBP between genders, the present study found that LBP was higher in women (67.7%) compared with men (51.6%). It was found in 2 studies21,22 that LBP symptoms were consistently more common among women. Women continue to be the primary informal caregivers for the majority of children and older people in Asian countries and this too is a factor in women’s back pain syndromes. Hathorn et al 22 stated that the risk of LBP is higher among women because of the stress of hormonal changes, gynecological problems, and childbirth.
In the study sample, subjects with an educational level of high school graduation (23.6%) had higher chance of developing LBP than those with college graduation (20.5%). Low educational status, that is, below intermediate educational level (39.5%) has been shown to be associated with an increased prevalence of LBP, which is similar to the study findings of Kwon et al. 23 Also, majority of the patients with LBP had clerical jobs (28.8%). Among patients with LBP, more than half of the women (50.4%) were housewives, whereas most of the men (36.8%) had clerical jobs with a significant difference between both the genders in their occupation (P < .001). Economic status was very low in the LBP patients with monthly income (QRs [Qatari Riyal] 5000-10 000; (36.6%). Low monthly household income <QR10 000 was a significant predictor (OR = 1.38; P = .001) for LBP in patients studies. Waddell24(pp85-101) reported in his study that the prevalence of LBP may be slightly greater in those from a lower socioeconomic class.
Obesity (45.4%) and overweight (28.5%) were significantly higher in men and women with LBP. Stepwise logistic regression revealed that overweight (BMI > 30 kg/m2) was a strong contributing factor for LBP (OR = 3.26; P < .001), which is in accordance with earlier studies 25 that obesity or higher BMI was associated with an increased occurrence of LBP. Generally, it is believed that persons with good state of physical fitness appear to have a lesser risk of chronic LBP.
Life style habits had a great influence on patients with LBP. The present study indicated some of the exacerbating factors that male subjects with prolonged standing (41.2% vs 29.5%; P < .001) had significantly higher proportion as compared with their female counterparts. Also, exercise (18.7% vs 13.2%; P = .024), and coughing/sneezing/straining (9.7% vs 5.9%; P = .010) were reported as significant triggering factors for LBP among male participants as compared with females with LBP. It was reported 26 that factors such as heavy physical work, prolonged sitting, or standing, bending, twisting, pulling, and pushing have often been associated with LBP. In the study sample, smoking was a strong contributing factor for LBP (OR = 1.4, 95% CI = 1.11-1.77; P = .003), which is similar to findings in a study 27 that smoking was found to increase the risk for patients with LBP, whereas a systematic review of the epidemiologic literature 28 on smoking and LBP revealed that there was no consistency of statistically significant position associations between smoking and LBP. It showed that there is no consistent evidence in favor of a casual link between smoking and LBP and it concludes that smoking should be considered as a weak risk indicator and not a cause of LBP.
These study findings support the fact that LBP continues to be an important clinical, social, economic, and public health problem affecting the population of the entire world. It is clear that LBP is an extremely common problem, which most people experience at some point in their life. LBP is a common problem affecting both genders and most ages with a higher prevalence among women and in older age.
Conclusion
The epidemiologic analysis revealed that sociodemographic factors such as gender, marital status, low monthly income, overweight, and smoking status were the major contributors for the occurrence of LBP. Women were more likely to present with LBP than men. LBP was observed more frequently among older people and among those who were overweight. Prolonged standing and coughing/sneezing were reported as triggering factors for LBP among male patients.
Footnotes
Acknowledgements
The authors would like to thank Hamad Medical Corporation for their support and granting ethical approval (HMC RP# 12061/12).
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was generously supported and funded by the Qatar Foundation, UREP Grant No. 11-074-3-015.