Understanding the burden of chronic back pain: a spatial microsimulation of chronic back pain at small area level
Harrison Smalley1, Kimberley Edwards2
1Queens Medical Centre, School of Medicine, University of Nottingham, Nottingham, UK. harrison.smalley@nottingham.ac.uk.
Purpose:
Chronic back pain (CBP) carries a significant burden. Understanding how and why CBP prevalence varies spatially, as well as the potential impact of policies to decrease CBP would prove valuable for public health planning. This study aims to simulate and map the prevalence of CBP at ward-level across England, identify associations which may explain spatial variation, and explore 'what-if' scenarios for the impact of policies to increase physical activity (PA) on CBP.
Methods:
A two-stage static spatial microsimulation approach was used to simulate CBP prevalence in England, combining national-level CBP and PA data from the Health Survey for England with spatially disaggregated demographic data from the 2011 Census. The output was validated, mapped, and spatially analysed using geographically weighted regression. 'What-if' analysis assumed changes to individuals' moderate-to-vigorous physical activity (MVPA) levels.
Results:
Large significant clusters of high CBP prevalence were found predominantly in coastal areas and low prevalence in cities. Univariate analysis found a strong positive correlation between physical inactivity and CBP prevalence at ward-level (R2 = 0.735; Coefficient = 0.857). The local model showed the relationship to be stronger in/around cities (R2 = 0.815; Coefficient: Mean = 0.833, SD = 0.234, Range = 0.073-2.623). Multivariate modelling showed this relationship was largely explained by confounders (R2 = 0.924; Coefficient: Mean = 0.070, SD = 0.001, Range = 0.069-0.072). 'What-if' analysis showed a detectable reduction in CBP prevalence for increases in MVPA of 30 and 60 min (- 2.71%; 1, 164, 056 cases).
Conclusion:
CBP prevalence varies at ward-level across England. At ward-level, physical inactivity is strongly positively correlated with CBP. This relationship is largely explained by geographic variation in confounders (the proportion of residents that are: over 60, in low-skilled jobs, female, pregnant, obese, smokers, white or black, disabled). Policies to increase PA by 30 min weekly MVPA will likely result in a significant reduction in CBP prevalence. To maximise their impact, policies could be tailored to areas of high prevalence, which are identified by this study.
