One hundred and fifteen participants (115) were included in our study aged from 19 to 80 years, the mean being 52.62 (±12.65SD). There was a male to female sex ratio of 0.3. More than half of them (61.7%) were married and 45.2% were self-employed with 37.4% having an average monthly income lower than 50,000 FCFA and 30.4% earning more than 100,000 FCFA. The majority (57.9%) of employment types involved physical labour with 40.9% having a secondary educational level ( Table 1 ).

Out of the 115 participants of the study, 35 were alcohol consumers with the majority (36%) having an alcoholic index of 2 units per week. Most patients (89.6%) were non-smokers. Sick leave days were present in 53.8% of cases with the average number of days of work stoppage being 12.75 days (±12SD). Most patients were overweight (45.2%) with a mean BMI of 28.6 (±5SD). The median duration of CLBP was 7.15 (±7.5SD) years while the median duration of the current episode of LBP was 7 (±13.2SD) months and the median pain intensity was 7 (±2SD). Leg pain was present in 67.8% of patients, sensory neuropathy in 63.5% and BBDS in 20% of cases. The most requested radiological exam was radiography of the lumbar spine (45.2%) and lumbar osteoarthritis was found in 58 patients (62.4%). However, 22 patients were unable to perform any radiological exam at all. A specific cause of LBP was found in 34.4% of patients whereas in 65.6% of cases, the cause was non-specific. Hypertension was the most common comorbidity, found in 26.1% of patients and it was associated with diabetes mellitus in 11.3% of cases ( Table 2 ).

Medical treatment was used at least once in 98.3% of patients, but only 5 patients had recourse to surgery. Physiotherapy was used by 45% of patients, and always in combination with the other treatment modalities. The average cost of management per month was assessed and the median was 52,000 FCFA (±20,875SD) with the lowest being 4000 FCFA and the highest going up to 1,500,000 FCFA.

In regards to the Roland Morris Disability Questionnaire, 91 patients (79.1%) were classified as being “dysfunctional” with only 24 (20.9%) being “functional”. The median RMDQ score was 11.11 (±5.7SD), the minimum being 0 and the maximum being 21 on 24. Concerning the Oswestry Disability Questionnaire, 46 patients (40%) were classified as severely disabled with a median ODI score of 40%, the maximum being 86% and the minimum 0%. Using the Pearson’s correlation test, we established that there was a strong positive correlation (r = 0.765, p = 0.01) between the RMDQ and the ODI thus, either of them can be used in our study ( Figure 1 ). For the following data however, we will be using solely the ODI as our variable for disability.

The median value for psychological wellbeing was 56 (±17.3SD) with 53% of patients classified under “Poor psychological health” and 47% under “Good psychological health” the cut-off point being a score of 60% using the WHO-QOL assessment questionnaire. Sleep dissatisfaction was observed in 24.3% of patients.

Alcoholic index, pain intensity, cost of management, psychological wellbeing, sick day leaves, BMI and sleep satisfaction were identified as factors influencing disability in CLBP patients with p-value < 0.05 ( Table 3 , Figures 2-6 ).

Gender, level of education, alcohol consumption, leg pain, sensory neuropathy, and treatment type were identified as factors influencing disability in CLBP patients. p-value < 0.05 ( Table 4 ).

The variables that were found to be independently associated with disability with statistical significance after the Poisson regression were primary level of education (AOR = 1.104 95% CI [1.102 - 1.1205], p = 0.027), alcohol consumption (AOR = 0.876 95% CI [0.796 - 0.964], p = 0.007), a combination of treatment modalities (AOR = 1.085 95% CI [1.014 - 1.161], p = 0.018), pain intensity (AOR = 1.055 95% CI [1.030 - 1.080], p = 0.000), BMI (AOR = 1.006 95%CI [1.000 - 1.012], p = 0.045), psychological wellbeing (AOR = 0.994 95 % CI [0.992 - 0.996], p = 0.000) and sick leave days (AOR = 1.009 95% CI [1.006 - 1.012], p = 0.000) ( Table 5 ).

Existing evidence suggests that prevalence rates of chronic LBP increase with increasing age [12] . As compared to working-age adults, older adults are more likely to develop certain lower back pathologies. This aligns with our study in which the mean age of the study population was 52.62 years with 54% of the population aged 51 years and above.

For one man with chronic low back pain, there were 3 women and this does not come as a surprise as 50% of chronic pain conditions have a higher prevalence in women, with only 20% of conditions being more prevalent in men. A similar pattern was obtained in the study by Kahere et al. in 2019 [12] .

The mean number of sick day leaves during the previous month, attributable to LBP, was 12.71 days, similar with the findings of Doualla et al. in which the mean number of sick day leaves due to back pain was 6 ± 10 days [13] .

Most patients were self-employed and earned less than 50,000 FCFA per month. The work type usually involved physical labour in more than half of the cases. According to the socio-economic impact assessment report recently published by the National Institute of Statistics (INS), 53% of Cameroon’s households reported a decline in revenues from their family businesses in the 30 days before the survey, carried out in July 2021, in the framework of the report. In Yaounde, that percentage was 67% against 60% in Douala.

Primary and secondary level of education were the most prevalent among our patients and this is plausible when we consider the conclusion of a systemic review on formal education and back pain by Dionne et al. which stated that less well-educated people are more likely to be affected by disabling back pain [14] .

Using the RMDQ cut-off point proposed by Stratford PW. and Riddle DL. in 2016 [11] , we found the prevalence of CLBP-associated disability which was 79.1%. This is higher than the prevalence of 65% found in a study by Salvetti et al. in 2012 in Sao Polo [15] . This difference can be explained by the type of study design used and the difference in the socioeconomic settings of the two countries. Available prevalence studies systematically reviewed have identified high LBP prevalence rates in LMICs [5] . In addition, lifetime LBP prevalence in LMICs can be as high as 93%, with greater prevalence in working populations [16] .

The Roland Morris Disability Questionnaire (RMDQ) and the Oswestry Disability Index (ODI) are the two mainly used condition-specific patient reported outcomes and the choice of the tool used is generally operator dependent. In our study, the two had a strong level of association (r = 0.765, p < 0.05) and this is higher than the results of a study done in Korea (r = 0.592, p < 0.01) by Chung EJ et al. in 2013 [17] which can be explained by the bigger sample size of our study population.

Using the Oswestry Disability Index Questionnaire (ODI), 46 patients that is 40% of the study population were classified as severely disabled with a mean ODI score of 38.59% ± 16.55%, the maximum being 86% and the minimum 0%. This is in harmony with the results obtained from a study done in China in 2017 by Chin-Pang Lee et al. [18] where the mean ODI score was 31.4 ± 15.4.

Using the Pearson’s correlation test, we established that there was a strong positive correlation (r = 0.765, p = 0.01) between the RMDQ and the ODI thus either of them can be used in our study. For the following data however, we will be using solely the ODI as our variable for disability.

On bivariate analysis, pain intensity, and sick leave days had a strong to moderate positive correlation with disability.

The median pain intensity level was 7 ± 2SD and it was moderately correlated to disability (r = 0.678, p < 0.01). Our study suggested that pain intensity was independently associated with the level of disability and for every unit increase in pain, there was a 5.3% increase in disability (AOR: 1.055; 95% CI: 1.030 - 1.080, 0.000). This correlates with the findings of Doualla et al. [13] and can be explained by the fear avoidance theory.

Our study suggests that more than half of our study population had recourse to sick leave days during the month prior to the interview due to low back pain and this correlates moderately (r = 0.688, p < 0.01) and independently (AOR = 1.009, 95% CI = 1.006 - 1.012; 0.00) with the level of disability in these patients. For every unit increase in the number of sick leave days, there is a 0.9% increase in disability level. This is in contrast to the findings of Klemenc-Ketis Z. et al. in 2011 [19] where the number of sick leave days was not significantly associated with disability and can be explained by the difference in the study methods.

BMI had a weak positive correlation with disability (r = 0.225, p = 0.016) and was found to be independently associated with disability after regression (AOR: 1.006; 95% CI: 1.000 - 1.012, 0.045). This aligns with the results of an analytical cross-sectional study done by Teck et al. in 2016 which suggested that BMI and disability had a positive correlation in patients with CLBP [20] .

There was a strong negative correlation between psychological wellbeing and disability (r = −0.745, p < 0.01) and a 0.6% increase in disability level for every unit decrease in psychological wellbeing. This is in line with the findings of P. Manninen et al., and supports the theory of psychological wellbeing.

Sleep satisfaction had a moderately negative correlation with disability (r = −0.356, p < 0.01), however, there was no significant association between the two after multivariate regression. This is different from the results of Pagan R. et al. in 2017 where sleep satisfaction was significantly associated with disability as an independent variable [21] .

The American College of Physicians recommends firstly non-pharmacologic treatment modalities such as: exercise, acupuncture, physical therapy, spinal manipulation, in chronic low back pain. However, more often than not in our study, we saw patients who were being managed with a combination of these modalities, especially physiotherapy and pharmacotherapy (39.1%). Our study suggests that patients on combination therapy have a higher disability score than those on single therapy (AOR = 1.085; 95% CI = 1.014 - 1.161). These findings support the validity of the fear-avoidance model which suggests that the presence of psychological factors, such as fear of pain, catastrophising and depression after experiencing pain, leads to fear of movement, resulting in disuse and further disability.

History of alcohol consumption and alcoholic index were both found to be associated with disability to some extent. The results indicate that there is a weak positive correlation between the alcoholic index and the disability level (r = −0.216, p < 0.05) and the mean level of disability is higher in patients who are non-consumers (F = 14.56, p < 0.01). However, only the history of alcohol consumption was independently associated with the level of disability, that is, patients consuming alcohol were less likely to develop disability than those who didn’t (AOR: 0.876; 95% CI: 0.796 - 0.964, 0.007). This concords with the cohort study done in 2010 by Jensen et al. where lack of alcohol consumption was identified as a risk factor for increased pain and disability [22] .

Our findings indicated that mean ODI was higher in patients with lower level of education compared to those with high educational level (primary: 46.18, secondary: 35.74, tertiary: 30.17). Those with a low level of education were more at risk of being disabled compared to those with a high one (AOR: 1.104, 95% CI: 1.012 - 1.205, 0.027). This finding seems to support the theory of fundamental causes which states that when new opportunities for lowering mortality arise, higher socioeconomic groups will benefit more because of their greater material and non-material resources. That is higher-educated adults appear to effectively manage their resources (e.g., cognitive, noncognitive, social, economic) to avoid disease, disability, and premature death across vastly different contexts. Lacking this “personal firewall,” their less-educated peers are more exposed, vulnerable, and dependent on resources in those contexts.

Our findings suggest that the mean ODI is significantly higher in females (41.38 ± 14.622) compared to males (29.52 ± 19.342), however, gender was not significantly associated with the level of disability after regression thus, corroborating with the results of Doualla et al. [13] .

The presence of both leg pain and sensory neuropathy resulted in a higher ODI compared to their absence, but they were not significantly associated with disability after regression.