Prevalence and associated characteristics of recurrent non-specific low back pain in Zimbabwean adolescents: a cross-sectional study

Background: Until recently, non-specific low back pain (NSLBP) in adolescents was considered a rare phenomenon unlike in adults. The last two decades has shown an increasing amount of research highlighting the prevalence in this age group. Recent studies estimate lifetime prevalence at 7%-80%, point prevalence at 10%-15%, and prevalence of recurrent NSLBP at 13%-36%. In Zimbabwe, there is dearth of literature on the magnitude of the problem in adolescents. Therefore, the aims of the study were to determine the prevalence (lifetime, point, recurrent) and the nature of recurrent NSLBP reported by adolescents in secondary schools. Methods: A cross-sectional study was conducted using a questionnaire. A cluster sample of 544 adolescents (age 13-19 years) randomly derived from government schools participated in the study. Lifetime prevalence, point prevalence and prevalence of recurrent NSLBP were presented as percentages of the total population. Exact 95% confidence intervals were given. Chi-square test was used to evaluate the effect of gender and age on prevalence. Results: The students' response rate was 97.8%. The lifetime prevalence was 42.9% [95% confidence interval = 40.8-44.6] with no significant difference between sexes [X-2 (1) = 0.006, p = 0.94]. However, NSLBP peaked earlier in female students (13.9 years) than in male students (15 years) [t (226) = 4.21, p < 0.001]. About 10% of the adolescents reported having an episode of NSLBP on the day of the survey. However, female students (14.2%) were more affected on the day [X-2 (1) = 11.2, p < 0.001]. Twenty-nine percent of the adolescents experienced recurrent NSLBP with 78% experiencing at least three episodes in the last 12 months. On average, recurrent NSLBP reported was mild in intensity (4.8 +/- 1.9) on the visual analogue scale (VAS) and short in duration. Recurrent NSLBP was associated with sciatica in 20.9% of adolescents. Conclusions: NSLBP is a common occurrence among Zimbabwean adolescents in secondary schools. It increases with chronological age and is recurrent in the minority of adolescents. Although much of the symptomatology may be considered benign, the existence of recurrent NSLBP in adolescents before their work-life begins should be a concern to health professionals, teachers and parents.